ManagingIonising Radiations andRadioactive Substancesin Schools, etcL93September 2008

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Supporting practical science & technologyin schools & colleges

Acknowledgements:CLEAPSS acknowledges the help of about a dozen Radiation Protection Advisers, the staff of variousgovernment departments and agencies and others who worked with us to make what we believe to bewell-reasoned judgements in areas where there are differences of opinion between professionals workingin radiation protection and science education. Particular thanks are due to Ralph Whitcher, Health andSafety Manager for West Sussex County Council and Chair of the Safeguards in Science committee of theAssociation for Science Education (ASE), for many useful ideas. We hope that this publication will assisteveryone involved to ensure that practical teaching about radioactivity continues to be carried out legallyand safely.

This publication replaces the CLEAPSS guide L93 Managing Ionising Radiations and Radioactive Substances,August 2001.

Whilst CLEAPSS publications are normally strictly confidential, with circulation restricted to Members and AssociateMembers only, this edition was produced with financial support from the Department for Children, Schools andFamilies and thus is publicly available.© CLEAPSS 2008 CLEAPSS,

The Gardiner Building,Brunel Science Park,

Kingston Lane,UxbridgeUB8 3PQ

Tel: 01895 251496Fax: 01895 814372

E-mail: science@cleapss.org.ukWeb site: www.cleapss.org.uk

Foreword

ContentsPART A ROUTINE GUIDANCE FOR RADIATION PROTECTION SUPERVISORS (SCHOOLS) .......................... 1

1 PURPOSE AND SCOPE OF THIS GUIDE ............................................................................................................................. 11.1 Introduction................................................................................................................................................................ 11.2 Availability ................................................................................................................................................................. 11.3 Related guidance ........................................................................................................................................................ 21.4 Further help ............................................................................................................................................................... 21.5 Legislative background .............................................................................................................................................. 21.6 Teaching about ionising radiations............................................................................................................................ 31.7 Why school investigations with radioactive substances are safe................................................................................ 3

2 WHO DOES WHAT......................................................................................................................................................... 42.1 The radiation employer .............................................................................................................................................. 4

2.1.1 The role of the radiation employer ................................................................................................................... 42.1.2 Who is the employer? ....................................................................................................................................... 5

2.2 The Radiation Protection Adviser (RPA) ................................................................................................................... 52.2.1 The employer’s need for a Radiation Protection Adviser (RPA)...................................................................... 52.2.2 Who is the RPA? .............................................................................................................................................. 62.2.3 The role of the RPA.......................................................................................................................................... 62.2.4 The CLEAPSS RPA Service ............................................................................................................................ 7

2.3 Managing the sources within a school ....................................................................................................................... 82.3.1 Who should be in charge of radioactive sources?............................................................................................. 82.3.2 The role of the RPS (Schools) .......................................................................................................................... 9

2.4 Who may handle radioactive sources? ..................................................................................................................... 102.4.1 Teacher qualifications..................................................................................................................................... 102.4.2 Support-staff qualifications ............................................................................................................................ 102.4.3 Staff training................................................................................................................................................... 112.4.4 Students below the age of 16 .......................................................................................................................... 112.4.5 Students aged 16 and above............................................................................................................................ 112.4.6 Pregnant females and new mothers (staff or students).................................................................................... 12

3 DAY-TO-DAY MANAGEMENT OF THE SOURCES............................................................................................................ 123.1 Standard operating procedures and contingency plans ........................................................................................... 123.2 Standard school holding........................................................................................................................................... 133.3 X-ray equipment ....................................................................................................................................................... 143.4 Standard school experiments.................................................................................................................................... 163.5 The need for effective monitoring equipment ........................................................................................................... 163.6 Storage, labelling and security................................................................................................................................. 17

3.6.1 Source containers............................................................................................................................................ 173.6.2 Location of the radioactives store................................................................................................................... 173.6.3 Construction of the store................................................................................................................................. 173.6.4 Labelling the store .......................................................................................................................................... 183.6.5 Security .......................................................................................................................................................... 19

4 RECORD KEEPING AND AUDITING ............................................................................................................................... 194.1 What records are required? ..................................................................................................................................... 19

4.1.1 History of the sources ..................................................................................................................................... 204.1.2 Use log............................................................................................................................................................ 204.1.3 Auditing record............................................................................................................................................... 21

4.2 Auditing tasks ........................................................................................................................................................... 214.2.1 The reason for leak tests and contamination checks ....................................................................................... 214.2.2 Carrying out inspections and leak tests........................................................................................................... 224.2.3 Contamination checks .................................................................................................................................... 23

4.3 Checking the monitoring equipment works effectively ............................................................................................. 24

5 USEFUL CHECKLISTS, RECORD SHEETS, LETTERS ETC.................................................................................................. 255.1 Checklist for management of radioactive sources in schools ................................................................................... 275.2 Radioactive source history ....................................................................................................................................... 285.3 Use log for radioactive sources................................................................................................................................ 295.4 Audit record for radioactive sources and store ........................................................................................................ 305.5 Staff authorised to use/handle radioactive sources .................................................................................................. 315.6 Sample letter to supplier when purchasing radioactive sources .............................................................................. 325.7 Labels for protactinium and radon-220 generators ................................................................................................. 335.8 Sample letter for radiation employers to notify HSE................................................................................................ 345.9 List of radioactive sources held................................................................................................................................ 35

PART B GUIDANCE FOR ALL TEACHERS & TECHNICIANS HANDLING OR USING SOURCES................... 36

6 STANDARD OPERATING PROCEDURES (& CONTINGENCY PLANS) WHEN USING RADIOACTIVE SOURCES......................... 366.1 The need for standard operating procedures (“Local Rules”)................................................................................. 366.2 Ensuring staff awareness of the standard operating procedures.............................................................................. 36

7 RISK ASSESSMENTS WHEN USING RADIOACTIVE SOURCES ........................................................................................... 417.1 The need for risk assessments .................................................................................................................................. 417.2 Use of model risk assessments.................................................................................................................................. 417.3 Notes on these model risk assessments..................................................................................................................... 417.4 List of model risk assessments (including use, storage & disposal) ......................................................................... 42

PART C FURTHER GUIDANCE FOR RADIATION PROTECTION SUPERVISORS (SCHOOLS) ....................... 61

8 EMERGENCIES ........................................................................................................................................................... 618.1 Spills and decontamination ...................................................................................................................................... 61

8.1.1 Avoiding spills ............................................................................................................................................... 618.1.2 Anticipating a spill ......................................................................................................................................... 618.1.3 Action to be taken following a spill................................................................................................................ 628.1.4 Checking a source after a spill........................................................................................................................ 63

8.2 Misplacement or loss of a radioactive source .......................................................................................................... 64

9 OBTAINING RADIOACTIVE SUBSTANCES...................................................................................................................... 649.1 What sources can schools use? ................................................................................................................................ 64

9.1.1 Is approval needed? ........................................................................................................................................ 649.1.2 Limits set by the Exemption Orders ............................................................................................................... 659.1.3 Limits set by government education departments........................................................................................... 66

9.2 Buying radioactive sources ...................................................................................................................................... 679.2.1 Suitable sources.............................................................................................................................................. 679.2.2 Placing an order for a radioactive source........................................................................................................ 68

10 TRANSPORTATION OF RADIOACTIVE SOURCES ............................................................................................................ 6810.1 Driver awareness training........................................................................................................................................ 6910.2 Packaging................................................................................................................................................................. 6910.3 Labelling .................................................................................................................................................................. 7010.4 Documentation ......................................................................................................................................................... 70

11 DISPOSAL OF RADIOACTIVE SOURCES ......................................................................................................................... 7311.1 Reasons not to dispose of radioactive sources ......................................................................................................... 7311.2 Reasons to dispose of radioactive sources ............................................................................................................... 7411.3 Methods of disposal.................................................................................................................................................. 74

11.3.1 Very low-level radioactive waste (VLLW) .................................................................................................... 7411.3.2 Disposal of surplus radioactive sources.......................................................................................................... 7511.3.3 Disposal of uranium and thorium compounds ................................................................................................ 75

11.4 Organisations offering a disposal service ................................................................................................................ 7711.5 Summary of possible disposal methods .................................................................................................................... 79

12 DEFINITIONS AND DOSES............................................................................................................................................ 8112.1 Definitions................................................................................................................................................................ 8112.2 Dose ......................................................................................................................................................................... 8212.3 Dose from storage of school sources........................................................................................................................ 8312.4 Dose from background compared to a school radioactive source ........................................................................... 83

13 LEGISLATION, CODES OF PRACTICE AND GUIDANCE .................................................................................................... 85

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Part ARoutine Guidance for Radiation Protection

Supervisors (Schools)1 Purpose and scope of this guide

1.1 IntroductionThis publication is designed to support practical work involving radioactivesubstances in schools and colleges, providing guidance on their safe storage,handling and use. It is divided into three main parts:

Part A: This gives guidance on what the person responsible for the radioactivesubstances in the science department needs to know and do on a day-to-day basis,ie, how to manage the sources and their use.Part B: This gives guidance on what all teachers and technicians who use orhandle sources need to know and do. It provides a set of model standardoperating procedures (“Local Rules”), to be adapted as necessary for use in aparticular school or college.Part C: This gives further guidance for the person responsible on the moreunusual situations. It is for reference if the need arises. It covers variousemergencies, transporting sources, buying new sources or disposing of old ones.Most schools will not encounter these situations, or only very rarely. It also givesmore detailed background information, for example justifying the suggestedprocedures and explaining how the requirements of the legislation have changedover time.

This guide is thus a reference to be used by the person responsible for theradioactive substances in the science department. It is also a reference for theemployer and for the Radiation Protection Adviser as to what is considered goodpractice in school science. The employer should be familiar with this guide and alsowith one or other of the CLEAPSS leaflets PS46A, Radiation Protection in SchoolScience: Guidance for Employers - Information for local authorities or PS46B RadiationProtection in School Science: Guidance for Employers - Information for independent schools& colleges (including foundation & voluntary-aided schools).

1.2 AvailabilityWhereas CLEAPSS publications are normally available only to members, thisedition has been produced with financial support from the Department forChildren, Schools and Families (DCSF)1 and hence is publicly available on theCLEAPSS web site, www.cleapss.org.uk. It is intended to replace the guidancewhich the Department and its predecessors previously issued as AM1/92 The Use ofIonising Radiations in Education Establishments in England and Wales, which waswithdrawn for England as from 1st September 2008.

1 Previously Department for Education and Skills, DfES, Department for Education and Employment,

DfEE, and earlier variations.

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1.3 Related guidanceThe information provided in this guide will normally be sufficient for the day-to-day work. It also covers some unusual situations. CLEAPSS also publishes a guideR92, The Measurement of Radioactivity, which explains the detection andmeasurement of ionising radiations using a range of equipment suitable for theschool science laboratory. A further CLEAPSS publication, L256 Specification ofRadioactive Sources for School Use, is a technical document, mainly intended formanufacturers, suppliers and employers but will be available to school staff ifrequired. When buying new sources, employers may well insist that in futureschools only purchase those complying with this specification. In specific instances,other CLEAPSS publications, eg the Laboratory Handbook, Hazcards and Recipe Cardsmay also be relevant. Most publications are available on the CLEAPSS SciencePublications CD-ROM, which is updated and reissued to members annually.

1.4 Further helpIf the person responsible is unclear about any aspect of his or her work, CLEAPSSmembers may contact the CLEAPSS Helpline. In some cases, he or she may contactthe employer’s Radiation Protection Adviser (RPA) for advice (or, for some localauthorities, the initial contact may be the Radiation Protection Officer). However,the RPA’s legal role is to advise the employer on compliance with the IonisingRadiations Regulations 1999, not to provide a general radiological helpline.

1.5 Legislative backgroundWork with radioactive substances and ionising radiations is governed by legislation,which must be followed by all employers; see sections 9 and 13. In the past,legislation and guidance from the various government education departments hasinterpreted this legislation for maintained schools1 and colleges and has definedcategories of work. However, for schools in England, the legislation was repealed asfrom September 20082 and the guidance (AM1/92, see section 1.2 above)withdrawn. The legislation is still in place in Wales but we understand the WelshAssembly supports repeal in principle. Some very out-of-date guidance doesremain, at the moment, in Northern Ireland3. Institutions for further education inEngland have their own regulation dating from 20044. This is very similar to theregulation for schools which has now been repealed. There is thus a situation inEngland in which FE colleges are still regulated (by DIUS, the Department forInnovation, Universities and Skills) whilst schools are no longer regulated by theDCSF. We understand that there is an intention to address this at some point in thefuture.Our experience is that almost every maintained school, in which students are taughtup to the age of 18 years, has been using only sources in category C as defined byAM1/92 (B3 in Northern Ireland). Although not subject to government education

1 A “maintained school” means a community, foundation, voluntary aided or voluntary controlled

school [defined in the School Standards and Framework Act 1998, section 20 (7)].2 The Education (Hazardous Equipment and Material in Schools) (Removal of Restrictions on Use) (England)

Regulations, 2008.3 The use of Ionising Radiations in Educational Establishments, DENI, 1986.4 The Education (Hazardous Equipment and Materials) (England) Regulations, 2004.

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department guidance in recent years, most independent schools and colleges havefound it convenient and appropriate to work within this category voluntarily. Theprevious edition of this guide was therefore written specifically for category Cschools and this revised version takes similar limits as its starting point. A very fewschools and colleges may be carrying out unusual activities for which they needadditional guidance not found here. In such cases, CLEAPSS members may contactthe Helpline for advice.

1.6 Teaching about ionising radiationsEveryone is exposed to background radiation of varying levels, depending onwhere they live and what activities they undertake. Ionising radiations are undetect-able by the senses. Partly for this reason they tend to be feared to an irrationaldegree or just ignored.Radioactive materials are essential tools in many areas of scientific research anddevelopment. Ionising radiations are used widely in medicine, food processing,imaging, tracing chemical reactions, archaeological investigations, fire protection,electricity generation and numerous industrial processes.Teaching about ionising radiations helps people to develop a balanced attitudetowards the subject, neither blasé nor apprehensive. For many students, the study ofionising radiations at school may be their only opportunity to achieve this. Thevarious national curricula for science include work on atoms and radioactivity, soeveryone who teaches science to this level should know how to handle radioactivesubstances and perform demonstrations. Beyond GCSE, the study of ionisingradiations forms a very important part of many science courses in which responsiblestudents can safely carry out investigations themselves under careful supervision.Practical work in this subject provides a unique opportunity to undertakemeaningful investigations at the atomic level. A wide range of support materials,many free of charge, for teaching about ionising radiations is readily available.

1.7 Why school investigations with radioactive substances are safeSchool and college work involving ionising radiations is very safe because great carehas been taken in the choice of sources, control measures and procedures. However,all radioactive substances can cause harm if misused, so various aspects oflegislation, codes of practice and guidance must be followed; see section 13.Radiological protection is currently founded on the assumption that any ionisingradiation, at no matter how low a dose level, presents a hazard, ie, it has thepotential to cause harm1. There are three key principles of radiological protection.

Justification;showing that the benefits outweigh any detriment that the radiation mightcause. Optimisation;keeping all exposures as low as reasonably practicable (ALARP). Dose limitation;keeping the doses for workers below specified limits.

1 The background to this is explained in Topics in Safety, 3rd edition, ASE, 2001, ISBN 0 86357 316 9.

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The principles apply to the potential for accidental exposures as well as predictedexposures.In education, we try to design activities with ionising radiation to achieve thelearning objectives while keeping the exposures of students and staff as low asreasonably practicable.Background radiation varies from place to place in the UK, giving us each an annualeffective dose (a weighted dose which relates to the whole body)1 of between about1 and 10 millisievert (mSv). Medical radiation (X-rays and radioactive materialsused in diagnosis), gives an average diagnostic dose of 0.38 mSv per year perperson. By comparison, the dose received by the hand (not the whole body) duringa standard school demonstration will be no more than 0.01 mSv. Consequently ateacher could carry out hundreds of demonstrations in a year before acquiring adose equal to that from annual exposure to a typical background level. Doses tostudents observing demonstrations will be far lower.Nevertheless, before work with radioactive substances takes place, there must be aprior risk assessment. This is the employer’s responsibility. The Model RiskAssessments given in section 7 of this document cover all the likely situations inschool science (unless novel sources are introduced) but they may need somecustomisation to cover the detailed situation in a particular school or college.

2 Who does what

2.1 The radiation employer

2.1.1 The role of the radiation employerUnder the Ionising Radiations Regulations 19992, any employer who carries out workwith ionising radiations is deemed a ‘radiation employer’. The radiation employer• must notify the Health and Safety Executive (HSE) before work commences

with radioactive sources (hence schools must inform their employer beforedoing so);

• has the legal responsibility to ensure that there are safe systems of work whenusing radioactive substances;

• must consult (and may subsequently appoint) a Radiation Protection Adviser(RPA).

Under the Ionising Radiations Regulations 1999 (and the 1985 regulations which theyreplaced) all radiation employers have to notify the HSE3 before work starts withionising radiations or if there are significant changes to an existing notification (eg,if school moves to a new address or the employer changes)4. However, mostschools were using their sources long before notification became a requirement. Inany case, in some areas HSE granted a waiver from notification because the

1 See section 12.2 for more details about radiation dose.2 Or the Ionising Radiations Regulations (Northern Ireland) 2000.3 All statutory radiation notifications are now processed at one office: HSE, Phoenix House, 23-25

Cantelupe Road, East Grinstead, West Sussex, RH19 3BE; fax 01342 334257 or e-mailnotificationfor.ionisingradiation@hse.gsi.gov.uk.

4 This is a one-off notification, not before each use of sources commences.

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government education department had such information anyway. Such waivers nolong apply and all radiation employers should ensure they notify the HSE beforework commences or if the work address or employer change. Since notificationcannot be delegated, local authority schools (see section 2.1.2) must keep theauthority informed, eg about new sources they propose to acquire. Other schoolsand colleges can notify the HSE directly, using the Sample Letter given in section5.8.

2.1.2 Who is the employer?The employer is the organisation, or person, with whom the employee has his or hercontract of employment. At the time of writing (August 2008), the situation is asfollows.

Schools and colleges in England and Wales

In community and voluntary-controlled schools, the employer is the local authority(previously local education authority, LEA).In foundation, voluntary-aided and some independent schools (includingacademies) the employer will be the governing body.For some independent schools, the employer may be a trust or the proprietor.In post-16 colleges the employer will be the corporation of the college.In some PFI1 schools the teachers will have the employer stated above but someancillary staff (including technicians) may have a different employer. Where two ormore employers share the same premises they must collaborate on health and safetymatters.

Schools in Northern Ireland

In controlled schools, the appropriate Education and Library Board (ELB) iscurrently the employer but, when these are abolished in 2009, the Education andSkills Authority is expected to become the employer. However, at the time ofwriting details are not clear.In Catholic schools, the Catholic Council for Maintained Schools is normally theemployer of teaching staff, but safety management responsibilities are usuallyassumed by the appropriate ELB, which normally employs the technicians.Employees in Catholic schools unsure of their position are advised to check withtheir ELB.In voluntary grammar, integrated and independent schools, the employer is likelyto be the governing body, corporation, trust or proprietor.

2.2 The Radiation Protection Adviser (RPA)

2.2.1 The employer’s need for a Radiation Protection Adviser (RPA)The radiation employer must consult an RPA who is able to satisfy the HSE’scriteria of competence and has the requisite knowledge and experience to provideadvice on compliance with the regulations for the type of work normally carried outin schools. There may be a few instances in which the materials being used do not

1 Private Finance Initiative.

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require the appointment of an RPA (or notification to the HSE). The role of theconsulted RPA would then be no more than to tell the employer of that fact.However, in most circumstances, the advice is that the radiation employer shouldappoint an RPA in writing1. Before work begins, it is essential to know who theemployer is and the name of the RPA that the employer has consulted and/orappointed. Schools will not normally need to deal directly with the RPA – routineenquiries from members can be directed at the CLEAPSS Helpline or, where,relevant, a local authority officer.

2.2.2 Who is the RPA?Since January 2005 all RPAs must satisfy the Health and Safety Executive (HSE)Criteria of Competence2. These are very demanding and most local authorityofficers are unable to satisfy them. Accordingly, nearly all local authorities nowemploy someone outside the authority as RPA. This may be a member of staff froman organisation such as the Health Protection Agency (previously known as theNational Radiological Protection Board, NRPB) or the Northern Ireland RegionalMedical Physics Agency at Forster Green Hospital but over half the local authoritieschoose to subscribe to the CLEAPSS RPA Service (see section 2.2.4 below).Where the employer is not the local authority (including foundation and voluntaryaided schools and academies) a similar position arises. Employers have sometimesappointed RPAs though local contacts or via parents or ex-pupils, eg, from a nearbyuniversity physics department, a local hospital medical physics department or aprofessional organisation offering radiation protection services. Because of the morestringent requirements on the qualifications of RPAs since 2005 some former RPAshave been unable to continue. CLEAPSS has issued a leaflet giving guidance onwhere such schools might find an RPA3. However, there is a shortage of RPAs andstrategies that bring more of them into science education work, eg, personalcontacts, are welcomed.

2.2.3 The role of the RPAThe role of the RPA has been defined by the HSC (now merged into the HSE)4. TheRPA has a duty to advise the radiation employer on radiological protection andcompliance with the Ionising Radiations Regulations 1999. There are statutory matterson which a radiation employer must consult an RPA but many of these would notnormally apply to schools. Those likely to be of relevance are:

appropriate risk assessments for each activity involving work with ionisingradiation5;

1 More details on the employer’s responsibility for the management of ionising radiations and the

appointment of an RPA is given in the CLEAPSS leaflets PS46A, Radiation Protection in School Science:Guidance for Employers - Information for local authorities and PS46B Radiation Protection in School Science:Guidance for Employers - Information for independent schools & colleges (including foundation & voluntary-aided schools).

2 The current HSE Statement on Radiation Protection Advisers is available on the Internet atwww.hse.gov.uk/radiation/ionising/.

3 PS46B Radiation Protection in School Science: Guidance for Employers - Information for independent schools& colleges (including foundation & voluntary-aided schools).

4 Work with Ionising Radiation. Approved Code of Practice and Guidance, HSE, 2000. ISBN 0 7176 1746 7.5 Model risk assessments for radioactive sources used in schools are provided in section 7.

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drawing up contingency plans; selection and use of personal protective equipment (PPE); storage of and accounting for sources; training.

An RPA may also give pragmatic advice on radiological protection matters. Thepurpose of this guide is to provide advice for schools that RPAs will be happy toendorse. This will not obviate the need for employers to appoint RPAs but shouldensure a degree of consistency between schools, may help prevent unnecessarilybureaucratic systems and should define good practice in the education sector.The name and contact details for the RPA should appear in the school’s StandardOperating Procedures (“Local Rules”, see section 3.1) and in the sciencedepartment’s Health and Safety Policy1.Where an RPA is appointed to an individual school or college, s/he will usuallywant to visit that school occasionally (perhaps every 2 or 3 years) to monitor what isgoing on. Where an RPA is appointed to a local authority, s/he will usually visit asmall sample of the schools every year unless the authority is operating under theCLEAPSS RPA Scheme (see below), in which case a trained officer of the authoritywill visit instead.Emergencies involving ionising radiations in schools are highly unlikely and veryrare. Should one occur, the RPA can be expected to give advice. However, it is notthe responsibility nor the role of the RPA to take over and remedy any emergency,nor clear away any contamination, nor dispose of unwanted or damaged sources.These are all the responsibility of the school and/or the employer.

2.2.4 The CLEAPSS RPA ServiceWell over half the local authorities subscribe to the CLEAPSS RPA Service. Thisservice is optional and CLEAPSS itself is not the RPA. Membership of CLEAPSSdoes not automatically provide access to an RPA. CLEAPSS has contracts with anumber of fully-qualified and experienced RPAs who provide the RPA service.Some local authorities which subscribe to the CLEAPSS RPA Service are willing toextend the service to other establishments in their area – commonly foundation andvoluntary aided schools but sometimes also independent schools (includingacademies) and post-16 colleges. This is not straightforward, as an officer of theauthority would need to visit the school from time to time (see below). This isentirely at the discretion of the local authority. Strictly speaking, a radiationemployer should formally appoint the RPA and this will certainly have been doneby local authorities. However, when a local authority acts on behalf of schools forwhich it is not the employer it is usual to assume that the governing body or trusthas empowered the local authority to act on its behalf in respect of RPAappointments.As a condition of subscribing to the CLEAPSS RPA Service a local authority mustappoint one of its officers as Radiation Protection Officer (RPO). This is not a termrecognised in the legislation but is a convenient description of their role in theCLEAPSS RPA Service. The RPO acts as the link person between the schools and the

1 See CLEAPSS guide L223, Model Science Health and Safety Policy.

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RPA. Schools in the scheme will not normally need to contact the RPA directlythemselves, except perhaps in an emergency. In practice, some non-technical aspectsof the RPO role may be delegated to administrative staff. CLEAPSS providestraining for RPOs in the scheme.Generally, under the CLEAPSS RPA scheme, the RPA will not visit schools. Instead,the RPO will visit schools from time to time to monitor practice and procedure.S/he will check that the record of sources is accurate, that sources are appropriatelystored, that the log of source use is kept up to date, that sources are checked forleakage at suitable intervals and that the general source management and use isappropriate (see section 4). In other words, the role of the RPO is to reassure theemployer that its arrangements for radiation protection are working. The RPA willreceive information from the RPO about the sources held1 and will issue advice thatthe RPO will pass on to schools. The RPO then ensures that this advice isimplemented2.It is because of this monitoring role of a local authority officer that the CLEAPSSRPA Service cannot be offered to independent schools and colleges unless a localauthority is willing to carry out the monitoring. They will of course charge a fee forthis service. In the circumstances, many independent schools have found itbeneficial to appoint an RPA directly.

2.3 Managing the sources within a school

2.3.1 Who should be in charge of radioactive sources?Radioactive sources need day-to-day management, ie, checking, auditing, ensuringstaff training, etc (see section 3). The Ionising Radiations Regulations 19853 requiredone or more members of staff to be appointed as Radiation Protection Supervisor(RPS). The requirement has been reiterated in much guidance to educationestablishments since then. However, the Ionising Radiations Regulations 19994 nolonger require the majority of schools to have an RPS because the annual dosesreceived by staff and students are very low and schools will not normally need“supervised areas”. On the other hand, someone, whatever his or her title, musthave day-to-day responsibility for the safe storage, use and monitoring ofradioactive sources. In this guide, we are calling this person the RadiationProtection Supervisor (Schools) [RPS (Schools)] to achieve continuity with the pastwhilst emphasising that such persons have duties much less than those normally

1 Normally schools in the scheme are required to complete a detailed form (CLEAPSS RPA1) which is

copied to the RPA, who may then raise questions and ask the RPO to investigate.2 Note that some local authorities buy RPA services from the Health Protection Agency (HPA,

previously known as the National Radiological Protection Board, NRPB). The HPA uses slightlydifferent terminology to CLEAPSS. The local authority designates one of its officers as a RadiationProtection Supervisor, RPS (see also section 2.3.2). This person will have a very similar role to theRPO as defined above in the CLEAPSS scheme.

3 Or the Ionising Radiations Regulations (Northern Ireland) 1985.4 Or the Ionising Radiations Regulations (Northern Ireland) 2000.

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expected of an RPS1 and hence need less training. There may be a few circumstancesin which a school really does need a fully-trained RPS.The person in charge of sources should normally be a member of the scienceteaching staff, usually the head (or deputy head) of science or the most senior orexperienced physics teacher or perhaps the departmental health and safety officer.For the level of work in schools, government education departments have notrequired this person to have any formal training or qualifications in addition to thoseneeded to be able to teach science while health and safety legislation simply requires‘adequate training’. However, the employer will wish to ensure that thoseappointed are competent and fully aware of their role. The employer may well beadvised to do this by the RPA. In local authorities subscribing to the CLEAPSSscheme, part of the role of the RPO is to check what is happening. The RPS (Schools)should understand the basic principles of radiological protection and the relevantrequirements of the Ionising Radiations Regulations 19992. Attendance on a coursespecifically designed for school-level work is highly recommended. This type ofcourse is available from CLEAPSS3 and run in all parts of the country (exceptScotland).We normally recommend that the RPS (Schools) should not be a technician. This ismainly because technicians do not usually have a sufficient overview and activeinvolvement with all aspects of the use of radioactive sources, including classroompractices, and in some schools may find it difficult to enforce compliance with theStandard Operating Procedures (“Local Rules”). Whilst many technicians make animportant contribution to the safe use of sources and are involved in routinemonitoring, the actual management responsibility is more appropriately reservedfor a head of department or similar experienced teacher. There may, however, bevalid exceptions, especially in schools where there is high teacher turnover, where asenior and qualified member of the school’s support staff can be assigned overallmanagement of radioactive sources. Alternatively, a technician might be appointedas the deputy RPS (Schools), with day-to day oversight of the logging system, etc.

2.3.2 The role of the RPS (Schools)The RPS (Schools), should:

inform the employer before acquiring new sources (some employers mayhave a form to be completed);

be directly involved with work using ionising radiations, including practicalteaching;

be able to exercise suitable authority to ensure that all such work is carriedout in accordance with the school’s Standard Operating Procedures (“LocalRules”);

be able to exercise supervision, though need not be present all the time; 1 Note that if a local authority obtains its RPA service from the HPA (see section 2.2.2) the individual in

the school, ie the teacher i/c radioactive sources, may sometimes be referred to as the ‘authorisedperson’.

2 Or the Ionising Radiations Regulations (Northern Ireland) 2000.3 See the termly CLEAPSS Bulletin or web site (www.cleapss.org.uk) for courses currently planned. If

there are none planned in your area, please contact CLEAPSS as we may be able to arrangesomething.

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ensure all teachers and technicians (especially new ones) who need to handleor use sources are appropriately trained;

ensure that the radioactive sources are all accounted for and kept secure; ensure that equipment is maintained in good working order; ensure regular monitoring is carried out on radioactive sources, their

containers and stores; ensure that all records required are accurate, up-to-date and kept secure; know what to do in an emergency.

The RPS (Schools) should be aware of the hazards, risk assessments and controlmeasures associated with each radioactive source in his or her care. The immediateresponsibility for handling sources and the supervision of practical work may oftenbe delegated to other members of staff. Therefore, the RPS (Schools) should besatisfied that all persons involved are informed and trained to a level which enablesthem to carry out procedures safely. Such training could be carried out in-house, egat departmental meetings and a suitable record kept (see section 5.5).After radioactive sources have been used, the RPS (Schools) should be confidentthat they have all been replaced in the store and that the Use Log (see sections 4.1.2and 5.3) has been completed. Occasionally, schools have been embarrassed, when asource has disappeared, by staff not knowing when the sources were last seen (seesection 8.2).

2.4 Who may handle radioactive sources?Appropriately qualified and trained staff may handle all the radioactive sources. A listof those authorised to do so by the RPS (Schools) could be kept with the Use Log (seesections 4.1.2 and 5.3) or included in the Science Department Health and Safety Policy.However, the handling of sources by students is restricted. Advice for pregnant femalesand new mothers is also included here.

2.4.1 Teacher qualificationsThe qualifications required to handle radioactive sources are generally those of teachersappointed to permanent positions on the science staff1, although some basic radiationprotection training may be needed and this can be provided in-school. Trainees, sometemporary staff, or those for whom science is a secondary subject, may not be suitablyqualified. If they are to handle sources, they must be supervised by a teacher who isqualified, until the RPS (Schools) considers that they have gained sufficient knowledgeand experience.The RPS (Schools) should compile a list of teachers (and support staff) authorised tohandle/use radioactive sources (see section 5.5 for a pro forma) and ensure it is kept upto date. This could be kept in the science department Health and Safety Policy.

2.4.2 Support-staff qualificationsTechnical support staff have various levels of qualifications and experience. The RPS(Schools) should decide what functions (if any) they can reasonably be given. It is

1 This requirement assumes that schools have the Standard School Holding; see section 3.2. More

stringent requirements would apply in the few schools outside this category.

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important that technicians are confident and competent, if they are to deal withradioactive sources.In some establishments, technicians never handle radioactive sources; teachers alwayscollect and return sources from the store. In other schools, technicians transfer sourcesto laboratories, carry out annual monitoring and prepare half-life investigations.

2.4.3 Staff trainingThe RPS (Schools) must ensure that all those who work with ionising radiations andradioactive substances follow the school’s Standard Operating Procedures (“LocalRules”) and are aware of the contingency plans. To achieve this, the RPS (Schools)should check that each member of staff (teaching or non-teaching), who works withionising radiations, is competent and follows correct procedures. The RPS (Schools)should provide appropriate instruction, as a matter of course, in the following areas.

Security and storage arrangements. Record keeping. Safe handling of each type of radioactive source. The general principle of keeping exposure as low as possible. Correct use of associated equipment, particularly that used for monitoring

purposes. Appropriate methods for standard school experiments. Action to be taken if a source is dropped or a spill occurs and other

contingencies. When to seek help and advice from the RPS (Schools).

A brief record should be kept of the training provided. Training is particularlyimportant for newly-qualified or newly-recruited staff. Prior knowledge should not beassumed. Equipment often differs considerably from school to school.

2.4.4 Students below the age of 16Students below the age of 16 must not normally be allowed to handle radioactivesources. Work at this level is largely restricted to teacher demonstrations. As generallywith demonstrations, students should normally be kept at least 2 m away from thesources, partly to reduce the risk of pilfering. However, suitably-responsible and well-supervised students may use devices containing low-level radioactive sources (eg,small cloud chambers, spinthariscopes, smoke alarms, radioactive watch dials andradioactive rocks) in standard experiments, provided the sources are fully enclosed.Contamination of the fingers must be prevented, particularly with radioactive rocks,which should be stored in suitable transparent containers. All sources, whatever theiractivity, must never be left unattended by the teacher in charge.

2.4.5 Students aged 16 and aboveStudents aged 16 and above may handle sealed sources in order to carry out standardinvestigations of the properties of ionising radiations. The teacher in charge must besatisfied that the students are sufficiently responsible, have received appropriate inst-ruction and have seen and understood the appropriate sections of the StandardOperating Procedures. The teacher must closely supervise all work. The sources mustbe inspected for signs of damage as soon as they are returned to the teacher. Theprocedure for doing this is explained in section 4.2. All sources, whatever their activity,must never be left unattended by the teacher in charge.

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2.4.6 Pregnant females and new mothers (staff or students)It is always important for a pregnant employee to let her employer know as soon as sheis aware that she is pregnant, so that the employer may advise her of any specialprecautions or changes to working procedures1. This applies equally to students whomay be pregnant. The employer must carry out a risk assessment. In the context of thisdocument the task is likely to be delegated to the RPS (Schools).Provided the standard operating procedures are followed (see section 6), nobodyhandling radioactive materials in schools will receive an additional dose anywherenear the limits laid down by the regulations, even the lower limit for women duringpregnancy.A pregnant female or a new mother may continue to carry out normal procedures withsealed sources. However, if she is still concerned over the risk to her (unborn) child, itwould be advisable to ask another person to carry out the work on her behalf.Unnecessary stress is likely to be far more harmful than the radiation.In order to eliminate the already very low risk of contamination, we recommend thatpregnant females and new mothers do not carry out leak tests, contamination checks orwork with unsealed sources [eg, dealing with spills of radioactive substances, preparingprotactinium or radon-220 (thoron) generators, etc].

3 Day-to-day management of the sources

3.1 Standard operating procedures and contingency plansThe Ionising Radiations Regulations 19852 introduced the term “Local Rules” for the useof radioactive sources. The Ionising Radiations Regulations 19993 do not require localrules in the majority of schools, because the annual doses received by staff and studentsare very low. Until recently, however, guidance from government educationdepartments still recommended maintained schools to have local rules. All schools andcolleges need written information and instructions for their work with radioactivesubstances and contingency plans for various emergencies. However, we now thinkthat these day-to-day instructions are better described as Standard OperatingProcedures but doubtless many people will continue to use the term Local Rules.The employer (acting on the advice of the RPA) is responsible for preparing StandardOperating Procedures and contingency plans for the RPS (Schools). Model StandardOperating Procedures and contingency plans are printed in section 6, although somecustomisation may be needed for particular situations. All staff handling or workingwith ionising radiations should be familiar with, and have easy access to, theseprocedures. Students aged 16 years and above, who are allowed to carry out supervisedinvestigations with sealed sources, should also be given access to the appropriatesections of the operating procedures.

1 See CLEAPSS leaflet PS13, New & expectant mothers taking part in school science on the CLEAPSS Science

Publications CD-ROM.2 Or the Ionising Radiations Regulations (Northern Ireland) 1985.3 Or the Ionising Radiations Regulations (Northern Ireland) 2000.

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3.2 Standard school holdingProviding various conditions are met, several Exemption Orders made under theRadioactive Substances Act (including the Radioactive Substances (Schools, etc) ExemptionOrder) allow users of some radioactive sources to avoid having to register with theEnvironment Agency (which is expensive) (see section 9.1.2).Separately, for 40 years, government education departments, by means of regulationsor administrative memoranda (see section 9.1.3), exerted much tighter restrictions onmaintained schools than were required by the Schools Exemption Order and otherExemption Orders. Most independent schools also kept within or close to those limits.Holding sources in this category allowed schools to meet their educational objectivesand carry out a wide range of valuable practical work. The statutory basis of theserestrictions has now been withdrawn in England (see section 1.5), whilst the goodpractice aspects of the memoranda are brought forward within this guidance. Bearingin mind the three key processes of radiological protection (see section 1.7), justification,optimisation and dose limitation, in this guide we define a ‘Standard School Holding’,roughly equivalent to the limit which has worked successfully for many years andwhich we would encourage education departments in Wales and Northern Ireland toretain or adopt as well. See the illustration of typical sources on the next page. Ingeneral this guide assumes that schools will have no more than the Standard SchoolHolding and that the sources will be used for Standard School Experiments.The Standard School Holding comprises the following.

Up to 1.2 MBq (30 µCi) as approved sealed sources1 (eg, six 200 kBq (5 µCi)sources), so long as no single sealed source has an activity greater than 400 kBq(10 µCi).

Up to 100 g of uranium compounds, as chemicals2. Protactinium generators for half-life experiments. Radon-220 (thoron) generators for half-life experiments3. Up to 37 kBq caesium-137/barium-137 elution source4 for half-life experiments. Low activity (about 1 kBq) radium-paint cloud chamber sources. Low-level radioactive consumer artefacts such as protected luminous dials,

smoke alarms, gas mantles, thoriated tungsten electrodes and glass or ceramicitems (eg, Vaseline glass, Fiesta ware).

School spinthariscopes. Radioactive rocks5.

1 Based on nominal activity of the parent radionuclide, ie, the original activity stated on the source or

its container. Whilst most sources will become less active over time, a few will become more activeinitially because they produce radioactive decay products.

2 Thorium compounds are not regarded as part of the Standard School Holding, other than in radon-220generators.

3 Some employers do not permit radon-220 generators containing loose thorium compounds to beused; see section 7.

4 Some 370 kBq caesium-137/barium-137 elution sources are on the market but are not suitable for theStandard School Holding, as they would exceed the Exemption Order limit for disposal.

5 It may be inappropriate to keep particularly active specimens; see section 7.

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Schools could have one or two cobalt-60 sources in excess of the Standard School Holdingif these were so decayed as to be unusable for normal work, in order to compare themwith new ones, thus demonstrating decay over time1. They might also have a little morethan the Standard School Holding, for example if they operate on more than one site orhave unusually large amounts of post-16 student practical work. This would need to beagreed by the employer acting on the advice of the RPA. However, schools shouldavoid hoarding sources they do not need. Excessive holdings increase the risk of lossand would be difficult to justify under ALARP Principle2.This also assumes that the procedures carried out are recognised as ‘standard’, seesection 3.4, below. Should a school wish to keep sources significantly in excess of theStandard School Holding, or use different sources or carry out non-standard procedures,prior advice should be sought from the RPA. Special training, different operatingprocedures and contingency plans and dose calculations might be required.Sources not mentioned above (eg, radium-luminised equipment such as altimeters,compasses, etc), or kept in greater quantities than those listed, may need to be disposedof; see section 11. Information and model risk assessments for the most commonradioactive sources kept by schools are given in section 7. If it is not possible to identifya source, contact CLEAPSS or the RPA (via the RPO in local authorities subscribing tothe CLEAPSS scheme).As well as sources intended for educational use, the Standard School Holding also coverssome consumer items containing radioactive substances, the radiation from which canbe detected by a Geiger-Müller (GM) tube. These might include, for example, a smokealarm and older self-luminous watch or clock dials. It is essential that these consumeritems remain intact, sealed sources, usually in their original containers. They must notbe opened, adapted or mutilated in the interests of science or economy. Sometimesradium-luminised paint becomes brittle with age and, where there is evidence of this,items may need to be disposed of safely (see section 11).

3.3 X-ray equipmentX-ray equipment (such as a Tele-X-Ometer) is not regarded as part of the StandardSchool Holding but could be kept (but not used) if it is disabled by removing the mainsplug. Note that gas discharge and vacuum tubes such as those in the Teltron range,operating at up to 5 kV, do not produce significant X-rays and can be used.Should a school wish to use X-ray equipment and electron microscopes, prior adviceshould be sought from the RPA. Special training, different operating procedures andcontingency plans and dose calculations might be required.

1 A similar case could be made for strontium-90 but the longer half-life means that sources should be

usable for at least 40 years.2 ALARP: As Low As Reasonably Practicable.

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Typical items containing radioactive sources used in science laboratories

Information on their safe storage and use is provided in section 7. Drawings are not to scale.

Cup source Domestic glassware & ceramicitems

Perspex slide source

Protactinium generator Radon-220 (thoron) generator Protected luminous dial

Smoke alarm Gas mantles Expansion cloud chamber

Diffusion cloud chamber Spinthariscope Scintillation plate

Becquerel plate Radioactive rock Radioactive source housed inrecessed aluminium holder

(Iso-trak design)

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3.4 Standard school experimentsThese are experiments which it is reasonable to assume could take place in anysecondary school, although some are only relevant post-16. Indeed, they could beregarded as part of the essential curriculum to which any student is entitled, dependingon the level at which they are working.

• The existence of ionising radiations• Different methods of detecting ionising radiations• The existence of background radiation• That the emission is random in time• The different types of radiations and their main properties• The ranges of radiations in air and other materials• That the radiation intensity can be reduced to varying levels by different

materials• Radioactive decay• Half-life determination• Back-scattering of beta-radiation• The inverse square law for uncollimated gamma-radiation• The deflection of beta-radiation by a magnetic field

3.5 The need for effective monitoring equipmentEvery establishment, which keeps radioactive materials, must possess appropriate,working equipment to detect ionising radiations. (This is necessary even if the sourcesare not actually used.) In schools and colleges, this is usually a GM tube connected to asuitable measuring instrument1. The low count rates involved in leak tests andcontamination checks mean that the measuring instrument should be able to countdiscrete pulses from the GM tube. This type of instrument is known as a counter or ascaler. It will be necessary to check this equipment is working effectively, see section4.3. Small diameter GM tubes (such as those often supplied with data-logger sensors),although adequate for many standard experiments, are not suitable for monitoring,because they have too low an efficiency. A thin window GM tube (2 – 3 mg cm-2) of atleast 15 mm diameter is required, such as the ZP1481 GM tube (previously MX168)used over many years in schools2.Very occasionally, it may be necessary to carry out more-sensitive checks for contamin-ation or dose rate. This would only arise in very unusual situations. For example, aschool with an unusual source might want to reassure staff about the dose rate from it,or during disposal where a specialist contractor might require the information. In suchcases, more sophisticated monitoring equipment may be required and CLEAPSS or theRPA (via the RPO in local authorities subscribing to the CLEAPSS scheme) should becontacted for advice.

1 See CLEAPSS Laboratory Handbook, section 12 and CLEAPSS guide R92, The Measurement of Radio-

activity.2 A suitable alternative is the LND 72233, found in some schools. More information is given in the

CLEAPSS leaflet PS79 Radioactivity: Instrumentation for leak tests and contamination checks.

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3.6 Storage, labelling and securityRadioactive sources must be kept in suitable containers (“receptacles”) when not in use.These must be locked in a secure store when a member of staff is not supervising them1.

3.6.1 Source containersEach radioactive source should be kept in a suitably-labelled container. This is normallythe container in which the source was supplied. It allows the source to be identifiedeasily and carried safely. For example, the common cup source is kept in a lead potinside a wooden box. The labelling on each container should uniquely identify the

source(s) inside and include a trefoil warning sign, r, with the wording ‘radioactivematerial’. Specific guidance on appropriate containers for the sources commonly foundin schools is provided in section 7. Each source must be uniquely identified, if morethan one of the same type is held. If necessary, mark the outside of the container.

3.6.2 Location of the radioactives storeThe store for radioactive materials should be indoors, where security is better, access iseasier and corrosion damage to sources is minimised. It should not be in the same roomas the bulk storage of highly flammable material. This is to save fire fighters having toworry about radioactive sources and flammables at the same time. Neither should thesources be kept in a chemical store room where corrosive materials are also stored. Thestore will normally be in a prep room or laboratory, which is easily accessible from thearea(s) where the radioactive sources will be used. The store should be easy to reachand view the contents. (One source was reported lost to the HSE because it was noteasy to see what was at the back of the top shelf.)The dose rate at the surface of the store cupboard should be less than2.5 microsieverts / hour (see sections 12.2 and 12.3). Any container enclosing a gammasource will allow some radiation through. For this reason, and assuming the school hasonly the Standard School Holding, the radioactives store should be at least 2 m (ignoringwalls) from a place where anyone spends extended periods of time, usually interpretedas more than half the week. In a prep room, this means well away from the technician’sdesk and the washing-up sink. Do not overlook work locations above the ceiling orbelow the floor, if relevant. If the store is in a teaching laboratory, with differentstudents present throughout the day, it should be at least 1 m from areas wherestudents sit and at least 2 m away from the usual teacher position. Distances aremeasured in a straight line, through walls, floor or ceiling.The fire authority should be informed of the location of the store, usually via the schoolsite manager, who will liaise with the fire authority on these matters.

3.6.3 Construction of the storeThe minimum requirement for a radioactives store is a strong, steel container (such as atool box) which should be recognisable after a fire or other calamity. A lead container orlead-lined wooden container alone is insufficient protection in a fire. The steel containershould be kept in a fixed, locked cupboard or drawer, making sure there is no accessvia an adjacent cupboard or drawer.

1 The Ionising Radiations Regulations 1999, [or the Ionising Radiations Regulations (Northern Ireland) 2000]

Regulation 29. See also section 6 of this guide, Standard Operating Procedures, 1.6.

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Alternative storage arrangements for radioactive sources

A lockable, steel cupboard is preferable. This must be screwed or bolted securely to thefabric of the building. Educational suppliers usually offer a cupboard specificallydesigned for the purpose.Stock containers of unsealed sources may be placed on a small tray within the store, inorder to minimise problems in the unlikely event of a spill.Nothing other than radioactive substances and their immediate containers should bekept in the store, which means:

the store needs to be opened only when sources are required; every item kept in the store is radioactive, avoiding any possible confusion; in the unlikely event of a spill or leak, decontamination is much easier.

3.6.4 Labelling the storeThe outside of the cupboard or drawer (and the separate metal container, if used) mustbe marked with a warning sign. This must be of the standard triangular warning type,with a black trefoil pictogram on a yellow background with black edging1 (see below).Text (eg, Radioactive Sources Store) is optional, but serves as a useful reminder for usersunfamiliar with the symbol. A suitable sign can be printed in colour from the CLEAPSSdocument E232 Common Safety Signs and Hazard Symbols which is on the CLEAPSSScience Publications CD-ROM. Alternatively the coloured pictogram with captions canbe copied from the electronic version of this guide also on the CD-ROM. Good-quality,hard-wearing, self-adhesive warning signs are available from various suppliers2 andshould be used where possible.

Radioactive material

Standard warning sign for theradioactives store withrecommended text.

Authorised users only

1 The Health and Safety (Safety Signs and Signals) Regulations 1996 [or the Health and Safety (Safety Signs

and Signals) Regulations (Northern Ireland) 1996].2 Suitable signs are available from suppliers such as Seton Ltd (Tel: 0800 585501) and Safetyshop

(previously Signs and Labels Ltd) (Tel: 0800 132323).

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Teachers may come across the following symbol1. This is only intended for use insidethe containers of very high activity sources – the meaning of the running person shouldbe obvious - and will never be encountered in schools.

Do not use this symbolanywhere. It is reproduced herefor information only but it doesnot appear on the CLEAPSSScience Publications CD-ROM.

The local fire prevention officer may request that an additional standard warning signbe placed on the door of the room in which the radioactive sources are stored. While itis important that the site manager and fire authorities know where the radioactivesources are kept, advertising their presence could, in some circumstances, encouragevandalism or even theft by terrorists. Therefore it is important to review risks carefullybefore labelling room doors. Simply informing the Fire Brigade and the site managerwhere the sources are kept may be sufficient.It is useful to compile a list of the sources (see section 5.9), laminate it and fix it to theinside of the store cupboard to aid identification of the sources when they arewithdrawn and returned.

3.6.5 SecurityThe key to the store should be unique and kept securely. It is a good idea to keep aspare key at another secure location outside the science department, eg, in case of fire.Ideally, authorised staff should fetch sources from the store for immediate use andreturn. Whenever sources are outside the locked store, an authorised member of staffmust supervise them. Where temporary storage is required just before or after a lesson(eg, where a laboratory is far from the normal store), sources, in their containers, maybe locked for short periods in another cupboard or drawer. They should always bereturned to the normal store as soon as possible.Section 5.5 includes an example of a form which can be used to list the members of staffwho are authorised to handle and/or use radioactive sources. This could be included inthe science department Heath and Safety Policy and updated as staff move on and newstaff are trained.Security must be maintained at all times. Problems tend to arise especially whenschools or colleges are being merged, closed or refurbished.

4 Record keeping and auditing

4.1 What records are required?An appropriate record-keeping system must be in place in order to account for radio-active substances2 and to show that regular auditing of the sources and monitoring forleakage and contamination occurs. The records should be kept securely for as long as

1 From the International Atomic Energy Authority, IAEA, and the International Standards

Organisation, ISO.2 The Ionising Radiations Regulations 1999 [or the Ionising Radiations Regulations (Northern Ireland) 1999,

Regulation 28] and the Schools Exemption Order.

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the sources are kept and for at least two years (preferably more) beyond that1,2. In caseof loss or damage to the records, it is good practice to keep back-up copies in anotherbuilding (such as in the school office). Suggested formats for the documents requiredare given in section 5 and it may be helpful to refer to these whilst reading theparagraphs below. Three kinds of record are required:

• History of the sources• Use log for the sources• Auditing record of the sources.

4.1.1 History of the sourcesRegulations and/or good practice require there to be:

an individual record for each source, ie, the radioactive source history3 including,where possible, the:

unique name or reference number;radionuclide (and chemical name for radiochemicals);original activity of parent nuclide;delivery date and supplier.

results of inspections and leak tests on the source (see section 4.2) should also berecorded here. If the source is no longer kept, the history should include detailsof its disposal and, if not via the refuse collection or sewage system, writtenconfirmation from the organisation accepting responsibility for it (including thename and address) (see section 11 for information on disposal);

a copy of the approval letter from the appropriate government education depart-ment (this, in England, would only be for sources acquired by maintainedschools up to 2008 and any independent schools that opted into the system).

4.1.2 Use logThis should be completed every time a radioactive source is removed from, or returnedto, the store. It should show:

the source used; the date and time when the source was removed from the store (with signature); the name of the member of staff supervising the source; the teaching group present (including the names of any students aged 16 years

and above using the source);

1 Radioactive sources in schools and colleges are usually kept for many years. Original purchase

documentation is particularly useful if disposal becomes necessary. On very rare occasions employershave received enquiries about the safe use of sources, perhaps when former students or staff havehealth concerns. No case is known to CLEAPSS in which these types of sources have been found tocause a health problem. However, in these circumstances, it is helpful to have records to show thatsources have always been monitored and used correctly.

2 If a maintained school closes, the records should be passed to the local authority which could thenlodge them with the County Record Office or equivalent (for a fee). If an independent school closesthe management should consult the Records Management Society, Woodside, Coleheath Bottom,Speen, Princes Risborough, Bucks HP27 0SZ. Tel: 01494 488566; Fax: 01494 488590; E-mail: info@rms-gb.org.uk; Web site: www.rms-gb.org.uk.

3 A suitable ‘radioactive source history’ sheet is provided in section 5.2.

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the date and time when the source was returned to the store (with signature,confirming that the source is present in its container);

any other comments (eg, mass of radiochemical used).

Sometimes, the RPS (Schools) attaches the key to the store to the Use Log, so that staffare reminded to complete it. However, in this case both items must be kept securelyand preferably out of sight.An up-to-date list of staff authorised by the RPS (Schools) should be kept with the UseLog or in the science department Health and Safety Policy.

4.1.3 Auditing recordThis should be completed regularly, in order to verify that all other records, includingthose of inspection, leak tests and contamination checks (see section 4.2), are up to date.In particular, it provides formal confirmation that all radioactive sources are present inthe store.Regulations require that the whereabouts of sources are checked at ‘appropriateintervals’ but the HSE takes the view that monthly is the minimum. In most schools,sources are used over a period of a few days, and then not for another year. Providedthe Use Log is always completed correctly, the store is always locked and the key keptsecurely, a year would be an appropriate interval between detailed checks. However, atleast once a month there should be a simple, quick check that the boxes of sources are inthe locked steel cabinet – there is no need to remove the boxes and check individualsources. This is a task which could be delegated to a technician. However, if there aredoubts or, unusually, the sources are subject to frequent use and/or by severalmembers of staff, then more frequent detailed checking may be necessary. Whenever a(detailed) check is made for the presence of the sources, the containers will need to beremoved from the store and opened. This constitutes a ‘use’ of the sources and shouldtherefore be recorded as an entry in the use log.

4.2 Auditing tasks

4.2.1 The reason for leak tests and contamination checksIncidences of damage to, or failure of, radioactive sources used in schools and collegesare extremely rare. However, sealed sources have, very occasionally, been known toleak radioactive material and this might cause contamination of the immediate contain-ers and the surrounding area. Also a radium source may cause its container to becomeslightly contaminated after several years. This is quite normal – see below. Regularinspections, leak tests of sources and contamination checks of their containers aretherefore necessary1. CLEAPSS recommends that these are carried out annually2.The RPS (Schools) should ensure that monitoring for leaks and contamination takesplace. However, another member of staff who has received appropriate instruction maycarry out the actual work, eg, a technician. This should not be too time-consuming,

1 The Ionising Radiations Regulations 1999 [or the Ionising Radiations Regulations (Northern Ireland) 1999],

Regulation 27 (3); Working With Ionising Radiation, HSE Approved Code of Practice paragraph 483.2 The HSE Approved Code of Practice states that the interval between leak tests should not exceed 2 years.

CLEAPSS recommends annual testing, as it is less likely to be forgotten.

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provided the process is organised carefully. The RPS (Schools) should make sure thatrecords are updated when the tasks below are carried out; see section 5.Both leak tests and contamination checks use a GM tube to detect the unwantedpresence of radioactive material. Leak tests are performed on the sources themselves,whilst contamination checks are carried out on source containers, stores or surfaceswhere radioactive material may have been deposited.

4.2.2 Carrying out inspections and leak testsRegular inspections and leak tests ensure that the mechanisms for preventing dispersalof radioactive substances are functioning as intended. An inspection and leak testshould be carried out once a year on each source kept in the radioactives store. Asimple record will be necessary for each source1.A lab coat and disposable gloves should be worn (and a disposable dust mask if itemscontaining thorium powders are involved). Work should be carried out in a large tray(ideally enamel) or on at least two sheets of paper towel or newspaper. When work iscomplete, disposable materials used should be placed in a strong plastic bag which istied for disposal as very low-level waste; see section 11.3.1.One source should be inspected and tested at a time. Other sources, in their normalcontainers, should be at least 2 m away.

Physical inspection

Specific details relevant to each type of source are provided in section 7.The inspection of each source should be made in good lighting. Never look directly intoa sealed source, especially the aperture of a collimated source. A mirror held in theother hand enables the most active areas, eg, foils, to be viewed for a short time whenfacing away from the eyes (but for beta sources there will still be some back-scatterfrom the mirror). It is necessary to check for any damage or deterioration, particularlyto foils, plastic bottles and seals, which might result in the enclosed radioactivesubstance escaping from the source. If a source has any small blemishes, scratches etc,which will not affect its safe use, it is useful to make a note of these on the radioactivesource history sheet (a sketch may be appropriate). This information can assist in futureinspections, allowing fresh damage or deterioration to be detected more easily.

Procedure for leak test

Specific details relevant to each type of source are provided in section 7.A basic procedure for carrying out a leak test is given below.

A working GM tube and scaler must be available; see section 3.5. A good GMtube must be used; the small-window tubes (less than 15 mm diameter)sometimes used for data-logging are not suitable.

With all radioactive sources at least 2 m away, the background radiation in theworking area is counted for 2 minutes.

For cup sources, a piece of clean, cellulose filter paper is placed in the tray or onthe newspaper. The source is removed from its container with forceps. The openend of the source is gently wiped over an area of the paper about the size of the

1 A suitable ‘radioactive source history’ sheet is provided in section 5.2.

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GM tube window. The filter paper can be slightly moistened with ethanol ordilute detergent solution but it must not be over-dampened.

For other sources, including bottles, which cannot be wiped on paper easily, apiece of clean, dry, filter paper is folded to make a small pad with an area aboutthe size of the GM tube window. The paper is held in forceps and the pad gentlywiped over the surfaces of the source. The paper should not be moistened withethanol for sources which might be damaged by the solvent, eg, plastic slide(Labgear) sources.

Where appropriate, the source is returned to its container. The source is removed to a distance of at least 2 m. The GM tube window is held very close to, but not touching, the wiping surface

of the paper. Remove the plastic cap to maximise the GM detection efficiency. Itmay be convenient to set up a jig or a clamp to do this. The radioactivity on thetissue is estimated by counting again for 2 minutes.

If the count from the filter paper is less than 1.5 times background, the sourcehas passed the leak test.

Results of inspection and leak tests

The actual counts made should be recorded, together with an indication of pass/fail.However, if the source appears to be damaged or fails its leak test, a note should bemade of the action taken. The source should be kept inside its normal container, whichshould be placed in a strong plastic bag. This should be suitably sealed, labelled andkept in the usual store. CLEAPSS or the RPA (via the RPO in local authoritiessubscribing to the CLEAPSS scheme) should be consulted. Disposal may be necessary.

4.2.3 Contamination checksContamination checks should be carried out using precautions and procedures similarto those described for the leak tests above. Contamination checks should be made onany containers or store where there is a possibility that radioactive substances havebeen deposited on surfaces. In particular, radium source containers and the main radio-actives store should be checked every year and cleaned if necessary (see below).Sometimes cup sources can appear dirty, due to traces of lead oxide dust (from thecontainer). Such sources can be cleaned by holding the source with long-handledforceps and using a second pair to hold a piece of cotton wool, slightly dampened withwater containing a little detergent.In addition, if the school transports radioactive materials by road, then there should bea regular check of the packages used, to confirm that they have not becomecontaminated. Records must be kept for at least two years (and preferably muchlonger).

Radium sources

The slight emission of radon-222 gas by radium sources, which is inevitable, maydeposit small quantities of radioactive decay products on the outside of the source andthe inside of its container. This may cause a radium source apparently to fail its leaktest because its outer surface is contaminated, even though the source is not leakingradium. Every year, when the radium source is leak tested, the contamination level in

24

its container should be checked by wiping the inside of the empty container with cleanfilter paper1 held by forceps. The paper is then checked as for the leak test.If a radium source fails the leak test or its container fails the contamination test, thesource and its container should be carefully cleaned using filter paper moistened withdetergent, again held by forceps. Repeat this until the wipes pass the test. The sourceand container should be re-checked before the next use, to ensure there are no on-goingleaks. If contamination persists, CLEAPSS or the RPA (via the RPO in local authoritiessubscribing to the CLEAPSS scheme) should be consulted.

Radioactives store

Each year, all the sources should be removed from the radioactives store to a distanceof at least 2 m. An initial visual inspection may indicate possible areas of contamin-ation. A GM tube is then very slowly scanned over the inside of the store, keeping thewindow as close as possible to the surface without touching it. In particular, horizontalsurfaces and areas where possible contamination is visible should be checked.If the counter (scaler) does not have an audible output, it may be helpful to have oneperson watch the display while the other does the scanning.Any areas of apparently increased count rate over background should be investigatedin more detail, keeping the GM tube window within 5 mm of the surface. If a 2 minutereading of the activity of a suspect area reveals a count of more than 1.5 times back-ground, careful cleaning will be required using paper towels or tissues moistened witha detergent solution and held by forceps or tongs.If contamination is found in a radioactives store, it is important to find the origin of thecontamination (eg, a poorly-sealed radiochemical stock bottle) and deal with it follow-ing the procedures for inspection and leak testing described above.

4.3 Checking the monitoring equipment works effectivelyFormal calibration of the monitoring equipment used for leak tests and contaminationchecks by an accredited test house is expensive and unlikely to be necessary undernormal circumstances for schools working with the Standard School Holding2. If reallynecessary, the RPA or CLEAPSS itself may be able to loan a calibrated instrument.However, this would usually involve the cost of an RPA or CLEAPSS staff membervisiting the school.A basic calibration (as required by ISO 99783) can be achieved using the naturalradioactivity of all potassium compounds, due to the presence of 0.0117% of potassium-

1 As before, use cellulose filter paper. The filter paper can be slightly moistened with ethanol or dilute

detergent solution but it must not be over-dampened.2 Schools carrying out standard experiments using the Standard School Holding do not need Controlled

or Supervised Areas, as defined in the Ionising Radiations Regulations 1999 [or the Ionising RadiationsRegulations (Northern Ireland) 1999]. However, work with open sources, including making aprotactinium generator or opening bottles of radiochemicals as part of a disposal process might needsuch designation on a temporary basis. If so, the monitoring equipment may need calibration.

3 International Standard: Radiation Protection – Sealed Radioactive Sources – Leakage Test Methods, ISO9978:1992, International Organisation for Standardisation.

25

401. CLEAPSS can supply a procedure2 for using a known mass of potassium chlorideto make a Standard Test Source.

5 Useful checklists, record sheets, letters etcThis section contains various checklists, record sheets, letters, etc which the RPS(Schools) may find useful. They can be copied freely for internal use in schools andcolleges but must not be used commercially without prior CLEAPSS permission. Anelectronic version of each, for easy customisation, will appear in the CustomisableDocuments section of the annually updated CLEAPSS Science Publications CD-ROM3.The records should be kept securely for as long as the sources are kept and for at leasttwo years (and preferably much longer) beyond that.The following checklists, forms, etc are available.

5.1 Checklist for management of radioactive sources in schools

This form is designed to help the RPS (Schools) ensure that appropriate procedures arein place before, during and after work with radioactive sources. It is also a usefulchecklist for the employer when monitoring the management of radioactive sources inthe science department.

5.2 Radioactive source history

A radioactive source history sheet should be started for each radioactive source kept forscience teaching purposes (including protactinium generators, radon-220 generators,stock bottles of radiochemicals and any smoke alarms used for teaching purposes). Itshould be updated annually. It must be possible to identify uniquely each source. It isgood practice to give each source a reference number, particularly where several simil-ar sources are kept. Obviously, if there is only one radium-226 source in the school, thisin itself is sufficiently unique. However, if there is more than one, each needs to beidentifiable by means of a reference number or code. For example, on a cup source itmay be possible to slip a numbered sleeve over the stem. Beware school amalgamationswhere a school may end up with more than one example of a particular source. EnterNot Applicable, Not known or Uncertain where information is not available, (eg, whererecords of purchase are not available but purchase date has been estimated, or whereserial number is unclear or not present).

5.3 Use Log

Several copies of the use log sheet may be stapled together to form a booklet, possiblydouble sided and including thicker card as a cover. If sources have been given uniquereference numbers, these alone can be entered in the use log, making completion easier.The log should be completed whenever radioactive sources are removed from orreturned to the store.

1 This method is based on investigations carried out by Ralph Whitcher, RPA for West Sussex County

Council.2 PS79 Radioactivity: Instrumentation for Leak Tests and Contamination, CLEAPSS, 2008.3 Until the next CD-ROM is published, the file can be found on the members’ part of the CLEAPSS web

site, under Customisable Documents.

26

5.4 Audit record for radioactive sources and store

A complete audit of all the sources should be carried out at least annually, includingchecking that all the paperwork is in order and that the sources of have been checkedfor leakage. A single audit record can be used for several years. If “No” is entered inany column, a note should be made of the reason - immediate action is likely to berequired.

5.5 Staff authorised to use/handle radioactive sources

The list of staff authorised to use or handle radioactive sources should be kept up todate by the RPS (Schools). It might be kept with the other record sheets for radioactivesources or in the science department Health and Safety Policy.

5.6 Sample letter to supplier when purchasing radioactive sources

As there is the possibility for confusion because of differing requirements in differentparts of the UK and as between different types of schools and colleges, establishmentsordering radioactive sources may find it helpful to enclose a suitably customised copyof this letter when ordering radioactive sources from their suppliers.

5.7 Labels for protactinium and radon-220 generators

It may become necessary to replace the label on protactinium and radon-220 generatorsor to make a new label if the school prepares its own protactinium generator.

5.8 Sample letter for radiation employers to notify HSE

This letter should be used by the radiation employer to notify the HSE of an intentionto use radioactive sources (or to notify sources already in use). It should also be used ifthe employer changes or the name or address of the school change. The actual sourcesdo not need to be specified, hence new purchases or replacements do not requirenotification if the HSE has already been notified that the school holds sources.Employers should keep a copy of the notification sent to the HSE in case of futurequeries.

5.9 List of radioactive sources held

This list summarises the sources held by a school and points staff to the relevant ModelRisk Assessment in section 7. It can be attached to the radioactives store as a reminderof what should be there (see section 3.6.4) and could also be included with the standardoperating procedures (see section 6).

27

5.1 Checklist for management of radioactive sources in schools

Item Section inthisCLEAPSSguide

Tick

The employer has notified the HSE of the intention to use radioactive sources 2.1

The employer has appointed a Radiation Protection Adviser (RPA). 2.2

A Radiation Protection Supervisor (Schools) has been appointed. 2.3

Maintained (state) schools in Wales and Northern Ireland:An approval letter is on file from the appropriate government education depart-ment.

3.2 & 9.1.3

The standard operating procedures and contingency plans have been agreedwith the RPA.

3.1

The name and contact details of the RPS (Schools) and RPA have beenincluded in the Standard Operating Procedures and/or in the science departmenthealth and safety policy

6

A check has been made that all radioactive substances kept are suitable for usein education establishments.

3.2 & 7

A check has been made that the Standard School Holding is not exceeded. 3.2

Appropriate, working, monitoring equipment is available. 3.5

Satisfactory storage arrangements have been made for radioactive substances. 3.6

The fire authorities (probably via the site manager) have been told where theradioactive substances are kept.

3.6.2

A radioactive source history, for each source, includingthe results of regular inspections and leak tests.

4.1.1 & 5.2

The use log, completed whenever sources are used. 4.1.2 & 5.3

Documentationis in place andkept up to date.

The audit record, completed annually. 4.1.3 & 5.4

The RPS (Schools) is satisfied that staff authorised to handle or use radioactivesubstances are appropriately qualified.

2.4.1, 2.4.2& 5.5

The RPS (Schools) is satisfied that they are familiar withand understand the Standard Operating Procedures.

2.4.3 & 5.5For each memberof staff whohandles or usesradioactivesubstances:

The RPS (Schools) has provided appropriate instructionand training.

2.4.3 & 5.5

The RPS (Schools) has ensured that appropriate instruction and training is givento all students, particularly those aged 16 and above who handle sealedsources.

2.4.5

The RPS (Schools) regularly checks to ensure that sources have been returnedto the store.

4.1.3 & 5.4

Name of RPS (Schools) completing this form:

Signature: Date:

© CLEAPSS 2008

28

5.2 Radioactive source historyUnique name / reference number of source

Radionuclide / chemical name

Either the original activity (37 kBq = 1 µCi) kBq µCi

or, for an unsealed source, the original mass (orvolume) and specific activity

g (or cm3) kBq g-1

Delivery date(attach original paperwork if possible)

Supplier

Supplier catalogue number

Source serial number (sealed sources only)

Source manufacturer

Disposal date

For an unsealed source,mass used up or disposed of

Disposal to(include name and address and attach originalpaperwork if possible)

Sealed sources: Indicate significant blemishes,scratches etc, with dates when these were noted.A sketch of the source may be useful here.

(Inspect foils with a mirror.)

Inspection and leak tests (usually annual), including comment on any action taken, eg, decontamina-tion of a radium source and its container, referral to RPA if a source appears to be damaged or leaking.

Date Backgroundreading

(if relevant)

Inspection& leak test

reading

(if relevant)

Inspection &leak test (if

relevant) passed(less than 1.5 xbackground)?(yes or no)

Testcarried out

by

Comment(if any)

/ /08

/ /09

/ /10

/ /11

/ /12

/ /13

/ /14

/ /15

/ /16

/ /17

© CLEAPSS 2008

29

5.3 Use log for radioactive sources

Date & timeremoved

from store

Date & timereturnedto store

Source(s)used

Signaturerequired:

all source(s)present incontainers.

Memberof staff

supervisingsource(s)

Teaching group

Include names of anystudents aged 16 and above

using source(s).

(If a large number of students isinvolved, a separate list may be

required.)

Signaturerequired:

all source(s)present incontainers.

Comment(if any)

Include mass ofany radio-chemicalused up.

Use log, page number: © CLEAPSS 2008

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5.4 Audit record for radioactive sources and store

Date Sourcelist and

historiesup to date?(yes or no)

All sourcespresent,

inspected andleak tested?(yes or no)

Use log isup to date and

a back-upcopy has been

made?(yes or no)

Radioactivesstore

(& transportpackaging,if relevant)

inspected andchecked for

contamination?

(yes or no)

Signature of personi/c radioactive

sources

/ /08

/ /09

/ /10

/ /11

/ /12

/ /13

/ /14

/ /15

/ /16

/ /17

© CLEAPSS 2008

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5.5 Staff authorised to use/handle radioactive sources

… SchoolThe following members of staff have been authorised by the RPS (Schools) to handle and/or useradioactive sources from the date shown. (Delete names when an individual leaves the school). Thisform could be included in the science department Health and Safety Policy.Name Date Name Date

© CLEAPSS 2008

32

5.6 Sample letter to supplier when purchasing radioactive sources

This letter should be copied onto school headed stationery and adapted as appropriate.

Dear

Purchase of radioactive sourcesPlease supply the following radioactive sources:

The Radiation Protection Adviser (RPA) / Radiation Protection officer (RPO) for this school / college /local authority is … … … and s/he has agreed to this purchase (and a copy of her/his letter is attached).The employer of staff in this school / college requires that we purchase only sources complying with therecommendations in the document Design and Specification of Radioactive sources for School Use (CLEAPSSguide L256, by arrangement with the Department for Children, Schools & Families, 2008) and we believethat the above source(s) do(es) comply. After acquisition of this/these source(s) the school / college willremain within the Standard School Holding as defined in CLEAPSS guide L93 Managing Ionising Radiationsand Radioactive Substances in Schools, etc (2008).You will be aware that the Schools etc Exemption Order identifies the types of radioactive sources that maybe used in schools. It allows schools / colleges to hold up to:

148 MBq (4 mCi) of sealed sources; 74 MBq (2 mCi) of unsealed sources (but not strontium-90 and alpha-emitters).

This order is well within the specified limits. Other Exemption Orders also apply.In addition, in the past, maintained (state) schools and colleges have been required to have a Letter ofApproval (or Authorisation) from the Department for Children, Schools and Families (DCSF), previouslyknown as the Department for Education and Skills (DfES) and by similar names. That requirementchanged as from 1st September 2008.• All schools in England no longer need a Letter of Authorisation.• Independent schools across the UK no longer need a Letter of Authorisation.• Maintained (state) schools in Wales currently need a Letter of Authorisation from the Welsh

Assembly Government.• Maintained (state) schools in Northern Ireland currently need a Letter of Authorisation from the

Department of Education for Northern Ireland (DENI).If there are any enquiries about this order, please contact the school / college on … … … and ask for …… … … . However, if there is confusion about the legal position and the need for Letters of Approval,please contact CLEAPSS on 01895 251496 or e-mail science@cleapss.org.uk.

Yours sincerely

33

5.7 Labels for protactinium and radon-220 generators

For the protactinium generator

See Model Risk Assessments 9a and 9b (section 7).Label the outer plastic container and make a card version to keep in the tray.

PROTACTINIUM GENERATORDO NOT OPEN THE BOTTLE

Follow special instructions provided.Always use the bottle in a tray and keep a spill kit nearby.

In the event of a spill, cover with mineral absorbent andalert the Radiation Protection Supervisor (Schools)immediately.

Contains:

Concentrated hydrochloric acid (CORROSIVE);Uranyl(VI) nitrate-6-water (VERY TOXIC, RADIOACTIVE);Pentyl ethanoate (FLAMMABLE, HARMFUL).

Note: some generators may use alternative organic solvents and hence the label mayneed slight modification. See CLEAPSS Hazcards (available on the CLEAPSS SciencePublications CD-ROM) for relevant information.

For the radon-220 (thoron) generator (powder form)

See Model Risk Assessment 10 (section 7).Label the sealable plastic bag and make a card version to keep in the tray. Note that thisis not required for the gas mantle version of the radon-220 generator.

RADON-220 (THORON) GENERATORDO NOT OPEN THE BOTTLE

Follow special instructions provided. Always use the bottle in a tray and keeptissues or paper towels nearby.

In the event of a spill, carefully cover the area with damp tissues or paper towelsand alert the Radiation Protection Supervisor (Schools) immediately. The dustmust not be breathed in.

Do not remove the clip from the tube until the RPS (schools) has checked that thegenerator is properly connected to a sealed ionisation chamber. Keep the powderat the bottom of the bottle. Only squeeze the bottle very gently to transfer radongas into the ionisation chamber.

Contains:

Thorium hydroxide/carbonate (VERY TOXIC, RADIOACTIVE).

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5.8 Sample letter for radiation employers to notify HSE

Ionising Radiation: Statutory Notification

Name of employer

Address of employer

Contact telephone or fax or e-mail ofemployer

Premises at which work with ionisingradiation is to be carried out

As above(A local authority could instead insert “see attached” and attach alist of the addresses of all schools with radioactive sources, includinga contact telephone number or e-mail address for each)

Contact telephone or e-mail at premises atwhich work with ionising radiation is to becarried out

As above

Nature of the business of the employer Education

Categories of the sources to be used Sealed sourcesUnsealed radioactive substance

Date of this notification

Date on which work will commence Work already in progressUse of ionising radiation in schools was previously notified tothe Department for Children, Schools & Families (formerly,Department for Education & Skills and predecessors)

This letter should be copied onto headed stationery, adapted as appropriate and sent to:HSE, Phoenix House, 23-25 Cantelupe Road, East Grinstead, West Sussex, RH19 3BE;faxed to 01342 334257; or e-mailed to notificationfor.ionisingradiation@hse.gsi.gov.uk.

Schools for which the local authority is the employer should NOT use this letter but insteadinform the local authority, as it is the employer’s responsibility to notify the HSE.

35

5.9 List of radioactive sources held

Name / reference no. ofsource

Radionuclide / chemicalname

Original activity / mass Model risk assessmentnumber1

© CLEAPSS 2008

1 Numbered model risk assessments, for using the most common radioactive sources found in schools

and colleges, are provided in section 7 of this CLEAPSS guide, L93 Managing Ionising Radiations andRadioactive Substances (2008).

36

Part BGuidance for all teachers and technicians

handling or using sources6 Standard operating procedures (including contingency plans)

when using radioactive sources

6.1 The need for standard operating procedures (“Local Rules”)All employers need to ensure that standard operating procedures, includingcontingency plans for various emergencies, are in place for their work with radioactivematerials. In most schools, because the annual doses received by staff and students arevery low, it is not now a legal requirement to call these procedures “Local Rules”.However, this term has been used for many years and doubtless many schools willcontinue to use it.Model Standard Operating Procedures are suggested later in this section. However, itis likely that these will need some adaptation depending on local circumstances andthe exact nature of work being undertaken. CLEAPSS and the RPA (via the RPO forlocal authorities subscribing to the CLEAPSS service) can advise in case of difficulty.To facilitate customisation the Model Standard Operating Procedures will be availablein electronic form in the Customisable Documents section of the CLEAPSS SciencePublications CD-ROM1.

6.2 Ensuring staff awareness of the standard operating proceduresThe Radiation Protection Supervisor (Schools) [RPS (Schools)] is responsible forensuring that appropriate sections of the standard operating procedures andcontingency plans are brought to the attention of those staff and students who handleor use radioactive substances. Any necessary training should be provided by the RPS(Schools) before authorising staff to use or handle the sources.It is suggested that the following section, after any necessary customisation, should bemade easily available to relevant staff. An up-to-date, laminated set could be kept withthe apparatus used for teaching about radioactivity. The location information andcontact details at the end of the section might be included in the science departmentHealth and Safety Policy.

1 It will also be in the Customisable Documents section of the members’ only part of the CLEAPSS web

site.

37

… School: Standard operating procedures for the use of radioactive sources,including contingency plans

The standard operating procedures (previously known as local rules) are written to ensure that radiationdoses and risks of contamination are minimised. Following them, in addition to normal laboratory rulesand procedures, should ensure safe preparation and procedures for teaching about radioactivity. Theyalso include contingency plans for various emergencies which might arise. All staff (teachers andtechnicians) who handle or use radioactive sources should be familiar with the relevant parts.Should you have any uncertainties about these rules or what you have been asked to do, please clarifythe position with your RPS (Schools) before you begin work.1 Standard operating procedures for science department staff when any sources are handled

1.1 All activities involving sources of ionising radiation must be carried out or closely supervisedby a member of the staff who has satisfied the RPS (Schools) that he or she is competent todo so. An up to date list of such authorised people is kept with the Use Log and/or in thescience department Health and Safety Policy. In addition to these standard operatingprocedures, the RPS (Schools) will ensure that appropriate written instructions (such as theModel Risk Assessments in section 7 of the CLEAPSS guide, L93 Managing IonisingRadiations and Radioactive Substances in Schools & Colleges) and training are providedfor all those who handle radioactive substances.

1.2 Staff are expected to follow closely the Model Risk Assessments in section 7 of theCLEAPSS guide, L93 Managing Ionising Radiations and Radioactive Substances inSchools & Colleges, except where these have been modified for use in this particularschool.

1.3 The security of all radioactive substances is vital. In the event of a source being lost ormisplaced, an immediate search must begin and RPS (Schools) must be informed at once.Use a torch to search dark corners; completely empty the radioactives cupboard.(Sometimes sources have been put away with the GM tube and counter, especially thePanax S4 strontium-90 source which does not obviously look like a source.) If necessary,consult CLEAPSS for suggestions. However, if the source cannot be found, the RPS(Schools) will inform the RPA (via the RPO for local authorities subscribing to the CLEAPSSscheme) who will advise on the next course of action.

1.4 Before work begins with any radioactive source, the member of staff in charge must befamiliar with the correct procedure for its safe use, and suitably trained. This includes theprocedures required in the event of a source being dropped or spilt, ie, containment,clearing up and contamination checking. A working and suitably-sensitive radioactivitydetector, eg a thin end-window Geiger-Müller (GM) tube with at least a 15 mm windowdiameter and counter (scaler) and, where relevant, an appropriate spills kit1 must be to handduring all activities.

1.5 In the event of any incident resulting in contamination, the RPS (Schools) must be informedas soon as possible and must be satisfied that decontamination has been successfullycompleted. If appropriate, the RPS (Schools) must implement any further control measuresto avoid spreading contamination. The RPS (Schools) will consult CLEAPSS and/or theRPA (via the RPO for local authorities subscribing to the CLEAPSS scheme) if there is anyuncertainty.

1.6 Whenever a radioactive source is removed from, or returned to, the secure store, the UseLog must be completed. The person signing the Use Log must check that the sourcesare actually present in their containers. Where stocks of a radiochemical are used up,the approximate mass should be recorded.

1.7 Once sources have been removed from their secure store, they must never be leftunattended by a member of staff, unless temporary, secure storage has been arranged.Sources should be returned to the normal secure store as soon as possible after use.Where student behaviour is poor, it may be inappropriate to have radioactive sources in theclassroom at all, even for demonstrations.

1 See the CLEAPSS Laboratory Handbook, section 7, on the CLEAPSS Science Publications CD-ROM.

38

1.8 When carrying sources (even in their containers), the handling time should be minimised,particularly for gamma-emitting sources. A clear, uncluttered route to the destination,without pupils milling around, is essential. Where the journey is likely to take more than acouple of minutes, the source may be placed in an additional container (eg, a plastic bucket)to keep it away from the body (ie, the trunk).

1.9 Whenever students carry out work with radioactive sources, full training and, whereappropriate, written instructions, must be provided. Close supervision by a member of staffis essential at all times.

1.10 Students under the age of 16 must use no radioactive sources other than those in:• small cloud chambers (the source must remain inside the chamber during the

lesson);• watches or clocks with luminous dials;• radioactive geological specimens (kept in suitable containers which are not easy to

open).All other work with radioactive sources must be performed by teacher demonstration only.

1.11 Responsible students aged 16 years and above, may use other sources in addition to thoselisted in paragraph 1.10. As well as the requirements of paragraph 1.9 above, each studentmust be given a copy of section 2 and/or section 3, as appropriate, of these StandardOperating Procedures.

1.12 A member of staff must check sources immediately after use by students. Any suspecteddamage must be reported to the RPS (Schools) who will decide if further action ormonitoring is required. A record of any unusual incident involving a source should be keptwith the appropriate source history and noted in the Use Log.

1.13 In the event of a fire alarm when the sources are in use, they should be temporarily placedin an adjacent cupboard so that they are out of sight, locking it if possible. If it is an actualfire, the teacher should inform the fire officer that the sources are in that room.

2 Standard operating procedures for the use of sealed sources (staff and supervised studentsaged 16 years and above)

2.1 Each source should be carried in its storage container and kept there until it is required. Thecontainer should not be handled for longer than necessary.

2.2 Only one source at a time should be used in any one investigation. If the experimentinvolves comparison of two or more sources, only one should be out of its container at atime.

2.3 A source without an integral handle should be handled with a tool to keep the fingers awayfrom the source, typically 10 cm away.

2.4 Any source which emits more radiation in a particular direction (collimated or non-isotropicsources) should be handled and positioned so the main beam is directed away fromanyone.

2.5 The source should be kept well away (30 cm) from the rest of the body and especially theeyes.

2.6 The investigation should be completed in the shortest time possible, consistent with goodresults.

2.7 The source should be returned to its normal container immediately after the investigation iscompleted.

2.8 The member of staff in charge must check all sources visually for signs of damage onreturn. [Never hold sources close to the eye and use a mirror where appropriate.]

2.9 Any event in which a source has been dropped or may have been damaged must bereported immediately to the member of staff in charge.

2.10 The hands must be washed thoroughly after working with any radioactive source.

39

3 Standard operating procedures for the use of sealed sources for half-life investigations(staff and supervised students aged 16 years and above)

eg, use of protactinium and radon-220 (thoron) generators.

3.1 Protactinium generators should be kept upright in a sturdy, plastic container with a securelid.

3.2 Radon-220 generators containing a thorium compound in powder form should be kept in asturdy, sealable, plastic bag.

3.3 Before use, the generator bottle should be thoroughly inspected for any sign of damage.

3.4 During use, the generator bottle should be placed in or above a suitably-lined tray in orderto contain the contents in the unlikely event of a spill.

3.5 Under no circumstances should the user remove the top of a generator.

3.6 An appropriate spills kit must be readily available. Should a spill occur, it must be reportedimmediately. Staff must follow special procedures and the Standard Operating Proceduresfor unsealed sources must be applied.

3.7 The hands must be washed thoroughly after working with any radioactive source.

4 Standard operating procedures for unsealed sources (staff only)eg, during preparation of protactinium or radon-220 generators and disposal of unsealed sources.

4.1 Work should not be carried out with unsealed sources (such as radiochemicals) if there areany uncovered open or partly-healed wounds on the hand. Cover any such wound with asuitable waterproof dressing.

4.2 A lab coat and disposable gloves must be worn. Eye protection will be required if otherhazardous chemicals are in use (such as concentrated hydrochloric acid used in theprotactinium generator).

4.3 Where the unsealed source is a fine powder (eg, thorium compounds used in the radon-220generator), work in a draught-free area. Wear a disposable dust mask (to EuropeanStandard EN149 category FFP3).

4.4 The work area should be prepared as follows.The bottom layer must be impervious to liquids (eg, an enamel tray or polythene on awooden bench). Above this, two or more layers of absorbing paper towel should be used tocatch spills. All glassware, test-tube racks and source containers should be placed on thepaper. A box of tissues should be immediately to hand. All other equipment should be keptoff the paper, but within reach.

4.5 If operating equipment (such as a balance), a clean tissue should be held in the glovedhand so that the knobs etc cannot be contaminated.

4.6 The member of staff who carries out any procedure with unsealed sources must clear upimmediately after the work is complete. He or she must:• flush liquid residues down a fast-flowing sink using plenty of water, but avoid

splashes;• wash all glass and plastics ware in a bowl and wash with detergent;• place all paper, tissues, dust mask, gloves etc in a strong, unlabelled plastic bag,

which is tied for disposal in the refuse;• place the bag directly into a main waste bin (outside the building), which will be

emptied by a refuse contractor. Do this shortly before expected collection.

4.7 The times of issue and return of radioactive substances should be recorded in the Use Log.The mass of any unsealed source used should also be recorded.

4.8 After finishing work with radioactive substances, check that the work area is free ofcontamination. If there is any suspicion of contamination, follow the guidance in section 4.2of the CLEAPSS guide, L93 Managing Ionising Radiations and Radioactive Substances inSchools & Colleges.

4.9 The hands must be washed thoroughly after working with any radioactive source.

40

5 Location of documentation

Documentation Location

Radioactive source history

Use log for radioactive sources

Audit record for radioactive sources and store

List of authorised users of radioactive sources

List of radioactive sources held

6 Contact details

School or college Name:

Radiation employer (tick one box only and, ifticking first or third box, insert name)

Local authority

Governing body

Other

………………

………………

Name:

(Internal) telephone:

Radiation Protection Supervisor (Schools)

[RPS (Schools)]

If cannot be contacted, contact CLEAPSS (below) E-mail:

Name of RPA:

Name of RPO (if applicable):

Address:

E-mail:

Radiation Protection Adviser (RPA)

Fill in the contact details for the RPA, unless thelocal authority subscribes to the CLEAPSS scheme.In that case, give the name of both the RPA and theRadiation Protection Officer, RPO, but give thecontact details only of the RPO and tick the boxbelow.

RPA via CLEAPSS scheme

If cannot be contacted, contact CLEAPSS (below)Telephone:

Name:

Address:

Local hospitalfrom which advice may be sought or to whichcasualties should be referred in the event of aradiation incident causing apparent or potentialinjury.

(If the local authority subscribes to the CLEAPSSRPA scheme, the RPO will usually obtain this andpass on the information to schools.) Telephone:

Emergency Contact : CLEAPSS 01895 251496

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7 Risk assessments when using radioactive sources

7.1 The need for risk assessmentsThe Ionising Radiations Regulations 19991 require suitable and sufficient risk assessmentsto be made before work is carried out2. This requirement for a prior risk assessmentcomplements the related requirements of the Management of Health and Safety at WorkRegulations 19993. The RPS (Schools) should ensure that members of staff, who useradioactive sources, are familiar with the hazards and control measures associated witheach.

7.2 Use of model risk assessmentsThe following sheets provide model risk assessments for using the most commonradioactive sources found in schools and colleges. As with all model risk assessments,adaptation must be considered to cover the special circumstances of a particularestablishment, class or teacher. For example, if the management is not sufficientlyeffective to ensure that appropriate control measures will be followed, it may be unsafeto store or use a particular source (this applies particularly to radon-220 generators).Similarly, if there are serious behaviour problems in a particular class, use of anyradioactive sources may be inappropriate.Should radioactive sources other than those listed here be stored or used in the school,we advise that similar risk assessments are produced and agreed between the RPA andRPS (Schools). CLEAPSS can advise members.

7.3 Notes on these model risk assessmentsRadioactive sources rarely emit only one type of ionising radiation. The most signific-ant radiations are given for each source. Those given in parenthesis may need to betaken into account when planning investigations about the properties of the differentradiations.Several references are made to “large forceps” as a handling tool for radioactivesources. These are intended to keep the hands well away from the source. CLEAPSSrecommends 300 mm extra-long, stainless-steel forceps4.Sources must be inspected and leak-tested regularly; see section 4.2 of this guide.

1 Or the Ionising Radiations Regulations (Northern Ireland) 1999.2 The Ionising Radiations Regulations 1999 [or the Ionising Radiations Regulations (Northern Ireland) 1999],

Regulation 7.3 Or the Management of Health and Safety at Work Regulations (Northern Ireland) 2000.4 Extra-long (300 mm, 12 inch) stainless-steel forceps, eg from Philip Harris (cat. no. B8R00176).

42

7.4 List of model risk assessments (including use, storage & disposal)

1 Radioactive rock: use, storage & disposal

2 Smoke alarm: use, storage & disposal

3 Luminous dial and spinthariscope: use, storage & disposal

4 Becquerel plate and scintillation plate use, storage & disposal

5 Diffusion cloud-chamber source use, storage & disposal

6 Expansion cloud-chamber source use, storage & disposal

7 Perspex slide source: use, storage & disposal

8a Cup sources: use, storage & disposal

8b Panax source S4: use, storage & disposal

8c Iso-trak sources (recessed in aluminium rod): use, storage & disposal

9a Protactinium generator: use, storage & disposal

9b Making a protactinium generator

10 Radon-220 (thoron) generator (powder version): use, storage & disposal(not permitted by some employers)

11 Radon-220 (thoron) generator (gas mantle version): use, storage & disposal

12 Gas mantles (impregnated with thorium compound): use, storage & disposal

13 Caesium-137/barium-137 elution source: use, storage & disposal

14 Domestic glassware and ceramic items, coloured with radioactivecompounds: use, storage & disposal

15 Thoriated tungsten welding rod: use, storage & disposal

Information and Model Risk Assessments for Radioactive Sources

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1 Radioactive rock: use, storage & disposalDescription Typical radioactive minerals offered by educational supp-

liers are allanite, autunite, davidite, monazite, phosphur-anylite, pitchblende and torbenite.These usually contain thorium or uranium minerals.The geography or geology department may also keeprocks of this type and the RPS (Schools) may wish toensure that the control measures described here areapplied as in the science area.

Use To demonstrate that natural rocks contain radioactive minerals. A rock should beregarded as radioactive if the count rate at the surface is more than 50% above thebackground count.

Supplier Supplied, for example, by Philip Harris or Griffin & George as a set. Sometimescollected in the field by enthusiastic students, geology or physics teachers.

Original activity Typically from 0.18 kBq g-1 to 5 kBq g-1.

Radionuclide Thorium and/or uranium.

Main ionising radiations α, β, γ in any combination.

Half life Typically millions of years.

Hazard External irradiation of the body, including possibly more-sensitive organs such asthe eyes. Internal irradiation of the body arising from rock fragments which haveentered by inhalation, absorption through the skin, ingestion or through wounds.

Risk assessment The residual risk is low with the control measures in place. However, where large,and/or particularly active specimens are kept, the RPA should be consulted foradvice.

Control measures Always follow the standard operating procedures for the use of radioactivesources.Radioactive rocks should be treated in the same way as other radioactive sources.

During use The lid of the container may be removed for inspection or checking the rock with aGM tube. The rock should not be touched with the hands. Beware of the possibilityof loose contamination.

Inspection Annually or after use by students. A rock should be checked for damage and anychips or fragments disposed of. Forceps or disposable gloves should be used tohandle rocks. Care should be taken to avoid chipping the rock with forceps. Hand-ling time with gloves should be kept short.

Leak test of source Not required.

Contamination checkof container

Annually or if damage to the rock is suspected.The container should be cleaned if necessary.

Storage and labelling Radioactive rocks are best stored in sturdy, transparent, plastic or glass containerswith secure lids, labelled with a radioactive warning sign and kept in the radioactivesstore or a locked drawer or cupboard. Should rocks be displayed, they must be keptin a locked cabinet. The count rate on the outside surface of the glass must besimilar to the background level. Rocks of high activity should not be displayed.

Spills A lab coat and disposable gloves should be worn. Should a radioactive rock bedropped, the area on to which it fell must be checked for contamination and decont-aminated if necessary.

Disposal

© CLEAPSS 2008

Small quantities of radioactive rocks may be disposed of in a strong plastic bag, tiedand put in the refuse. This is provided that the amount does not exceed 100 g ofuranium and thorium per day (500g of rock will contain usually much less than 100gof uranium or thorium, although some samples of pitchblende may contain up to70%); and the refuse is collected by your local authority’s internal waste contractoror by an external contractor who operates on contract to your local authority (even ifthere is a separate contract for your school), or, if it is a non-local authoritycontractor, the refuse goes to landfill.

Information and Model Risk Assessments for Radioactive Sources

44

2 Smoke alarm: use, storage & disposal

Description Most domestic smoke alarms use an ionisation chambersmoke detector. This is a small metal chamber containinga radioactive source. If smoke enters the chamber, thelevel of ionisation reduces, decreasing the flow of electriccurrent in a circuit and triggering a siren.

Use To show that many domestic smoke alarms contain a radioactive source. To explainthe widespread agreement that the very low radiological risk and the substantialbenefits in terms of life-saving, make it well worth installing such devices in thehome.

Supplier Hardware stores.

Original activity Typically 37 kBq (1 µCi).

Radionuclide Americium-241.

Main ionising radiations α, γ.

Half life 458 years.

Hazard External irradiation of the body, including possibly more-sensitive organs such asthe eyes. Internal irradiation of the body arising from substances which have enteredby inhalation, by absorption through the skin, by ingestion or through wounds.

Risk assessment The residual risk is low with the control measures in place.Note: such control measures are not required for smoke alarms used in the home,which are extremely unlikely to suffer damage in the normal position on the ceiling.Climbing a step ladder to reach the alarm is likely to present a far greater risk tohealth and safety than the radioactive material.

Control measures Always follow the standard operating procedures for the use of radioactivesources.

During use The plastic cover of the smoke alarm may be opened for observation, to detectionising radiation and to insert the battery. Under no circumstances should the metalionisation chamber be opened.The test button or smoke can be used to trigger the alarm.

Inspection Annually and after use by students.Check that the ionisation chamber is undamaged.

Leak test of source Annually or if damage is suspected.The accessible surfaces of the ionisation chamber should be tested.

Contamination checkof container

Not required unless leakage is suspected.

Storage and labelling A smoke alarm should be put in a strong, self-sealing, plastic bag (to avoid anycontamination from other sources), labelled with a radioactive warning sign and keptin the radioactives store.

Spills A lab coat and disposable gloves should be worn. If a smoke alarm is dropped, it ismost unlikely that any radioactive spill will occur. Should damage occur, the frag-ments should be swept into a strong plastic bag, which is tied and put in the refuse.The area must be checked for contamination and decontaminated if necessary.

Disposal

© CLEAPSS 2008

In the refuse, securely wrapped in a strong plastic bag, provided that there is notmore than 1 smoke detector in any 0.1 m3 and the refuse is collected by your localauthority’s internal waste contractor or by external contractor who operates oncontract to your local authority (even if there is a separate contract for your school).

Information and Model Risk Assessments for Radioactive Sources

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3 Luminous dial and spinthariscope: use, storage & disposalDescription Radium-based paint was in regular use in the first

half of the 20th century to make various objectsself-luminous in the dark. In a spinthariscope,scintillations are produced on a fluorescentscreen by the action of particles from aradioactive source.

Use To demonstrate that old watches, clocks and instruments with self-luminous dials use radio-active substances to make a fluorescent substance (usually zinc sulfide) glow.A spinthariscope demonstrates the particulate nature of ionising radiation. The user normallyneeds to spend 10 minutes or more in the dark before observation begins.

Supplier Luminous dials were often ‘donated’ by generous physics staff.Spinthariscopes were usually supplied by Philip Harris.

Original activity Luminous dials: normally weak. Spinthariscope: typically 0.74 kBq (0.02 µCi).

Radionuclide Usually Radium-226 (promethium-147 and tritium have also been used).

Main ionising radiations Radium-226: α, β, γ. Promethium and tritium: low energy β.

Half life Radium-226: 1602 years; promethium-147: 2.6 years; tritium 12.6 years.

Hazard External irradiation of the body, including possibly more-sensitive organs such as the eyes.Internal irradiation of the body arising from flakes of self-luminous paint which have enteredby inhalation, absorption through the skin, ingestion or through wounds. Tritium cannot bedetected by GM tubes.

Risk assessment The residual risk is low with the control measures in place. However, the radium-luminisedpaint in some older items can become brittle with age. This may flake and release fineparticles. These older items should be checked very carefully for contamination. Instrumentdials with luminous markings (especially military instruments such as altimeters andcompasses), produced before the regulations of the early 1960’s, may have activities of over370 kBq and may be poorly protected. They should not be kept. In cases of uncertainty,consult RPA.

Control measures Always follow the standard operating procedures for the use of radioactive sources.

Physical design It is important that all radioactive dials kept are securely encased, effectively making themsealed sources. Most luminous watches provide satisfactory protection. An old alarm clockusually has holes through which the controls pass and sometimes a loose-fitting face; theseshould be sealed with an epoxy resin (such as Araldite). An unprotected face from an oldinstrument or clock should be kept in a sealed, transparent, plastic container. The sourceinside a spinthariscope is very well encased.

During use No attempt should be made to operate any old instruments containing radioactive dials (suchas by blowing into pressure-operated altimeters). Demonstrations should be limited to usinga GM tube to demonstrate that the device is radioactive and opportunities given to view itemsin the dark.

Inspection Annually and after use by students. A check should be made that the visible luminous paint isnot crumbling, the glass is intact and that the luminous paint is completely enclosed.

Leak test of source Annually or if damage is suspected. The complete outer casing should be tested.

Contamination checkof container

Not required unless leakage is suspected.

Storage and labelling A fully-encased dial or spinthariscope should be kept in a strong, self-sealing, plastic bag,labelled with a radioactive warning sign and kept in the radioactives store.

Spills A lab coat, toxic dust mask1 and disposable gloves should be worn. If a luminous source isdropped, it is unlikely that any radioactive spill will result. Should damage occur, the frag-ments should be swept into a strong plastic bag, which is tied and put in the refuse. The areamust be checked for contamination and decontaminated if necessary.

Disposal

© CLEAPSS 2008

Dials can be disposed of in the normal refuse collection, wrapped in a strong plastic bag, ifEITHER, the dial carries the manufacturer’s mark “Ra 1.5” and there is no more than560 kBq (15 µCi) of Ra-226;OR the clock dial is unmarked and there is no more than 7.4 kBq (0.2 µCi) of Ra-226;OR the watch dial is unmarked and there is no more than 5.6 kBq (0.15 µCi) of Ra-226.For older, more active items, or spinthariscopes an authorised route is likely to be necessary.The RPA should be consulted.

1 European Standard EN149 category FFP3.

Information and Model Risk Assessments for Radioactive Sources

46

4 Becquerel plate and scintillation plate: use, storage & disposalA radioactive substance lines a recess in a plastic plate, normally protected by atransparent cover.

Description

Becquerel plate Scintillation plate

Typical dimensions (mm) Length 38, width 38, thickness 4. Length 50, width 25, thickness 4.

Use Used to produce blackening (fogging) ofphotographic plates, simulating HenriBecquerel's accidental discovery ofradioactivity.

Allows scintillations, produced by aradioactive material in a phosphor, to beobserved with a magnifier.

Radionuclide Uranium oxide paint or encapsulateduranium compound powder.

Various radioactive phosphors, oftenradium-226.

Supplier These sources have not been available for many years. Most were originally supp-lied by Griffin & George, Philip Harris and Panax. Some examination boardsprovided similar sources for practical examinations.

Original activity Weak.

Main ionising radiations α, β, γ.

Half life Various, but long.

Hazard External irradiation of the body, including possibly more-sensitive organs such asthe eyes. Internal irradiation of the body arising from substances which have enteredby inhalation, by absorption through the skin, by ingestion or through wounds.

Risk assessment The residual risk is low with the control measures in place.

Control measures Always follow the standard operating procedures for the use of radioactivesources.

During use These sources should be handled by the edges.

Inspection Annually and after use by students. This type of source should be checked forcrumbling of the active material and any damage to the plate or its cover.

Leak test of source Annually or if damage is suspected.The outer surfaces of the plate should be tested.

Contamination checkof container

Not required unless leakage is suspected.

Storage and labelling For successful use, scintillation plates should be kept in the dark to avoid fluoresc-ence caused by ambient light. They can be kept in any sturdy container, labelledwith a radioactive warning sign and kept in the radioactives store.

Spills A lab coat and disposable gloves should be worn. If a source is dropped, the areaon to which it fell must be checked for contamination. Decontamination may benecessary.

Disposal

© CLEAPSS 2008

A Becquerel plate containing a uranium compound could be disposed via the refusecollection, provided there is no more than 100 g per day of uranium compounds, thesource is grouted into a rugged container and the refuse is collected by your localauthority’s internal waste contractor or by an external contractor who operates oncontract to your local authority (even if there is a separate contract for yourschool).Otherwise, Becquerel plates must be disposed of via an authorised route.The RPA should be consulted.

Scintillation plates must be disposed of via an authorised route. The RPA should beconsulted.

Information and Model Risk Assessments for Radioactive Sources

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5 Diffusion (Taylor) cloud-chamber source: use, storage & disposalDescription This source is part of a diffusion (Taylor)

cloud chamber. It is a sample of radium-based luminous paint in a small metalcup attached to a stiff wire, which ismounted in a cork. See Model RiskAssessment 15, Thoriated TungstenWelding Rod for an alternative.

Typical dimensions (mm) Length 70, height 25, diameter of cup 5.

Use Observation of tracks produced by ionisation due to alpha particles.

Supplier Supplied by Griffin & George as part of a diffusion cloud chamber.

Original activity Typically 0.74 kBq (0.02 µCi).

Radionuclide Radium-226.

Main ionising radiations α, β, γ.

Half life 1602 years.

Hazard External irradiation of the body, including possibly more-sensitive organs such asthe eyes. Internal irradiation of the body arising from substances which have enteredby inhalation, by absorption through the skin, by ingestion or through wounds. Thepaint can become loose and contaminate the surroundings.

Risk assessment The residual risk is low with the control measures in place.

Control measures Always follow the standard operating procedures for the use of radioactivesources.

During use The radioactive end of the source should not be touched. The source should be keptin the cloud chamber.

Inspection Annually and after use by students. The sources should be checked for damage butmust be kept well away from the eyes. A mirror is useful for closer inspection. Theradium-based paint should not be crumbling or cracked.

Leak test of source Annually or if damage is suspected. The outer surfaces should be tested, takinggreat care not to damage the active sample.

Contamination checkof container

Not required, unless leakage is suspected. The amount of radium in this source isso small that contamination due to radon will be insignificant.

Storage and labelling The source should be removed from the cloud chamber by gently pulling out thecork and the wire mounting. Handling should be by the wire loop or the cork; theradioactive end should not be touched. Several sources may be kept together in aclosed, plastic, glass or metal container, labelled with a radioactive warning sign andkept in the radioactives store.

Spills A lab coat and disposable gloves should be worn. If a cloud chamber source isdropped, the area on to which it fell must be checked for contamination and decont-aminated if necessary.

Disposal

© CLEAPSS 2008

This type of source must be disposed of via an authorised route. The RPA should beconsulted.

Information and Model Risk Assessments for Radioactive Sources

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6 Expansion cloud-chamber source (Wilson cloud chamber source): use,storage & disposal

Description This source is part of an expansion (Wilson) cloudchamber. It consists of a radium source encapsulatedin silver foil held together by a brass assembly, whichscrews into the chamber.

Typical dimensions (mm) Diameter 7, height 8, (excluding threaded shaft).

Use Observation of tracks produced by ionisation due to alpha particles.

Supplier Supplied by Philip Harris as part of an expansion cloud-chamber apparatus.

Original activity Typically 37 kBq (1 µCi).

Radionuclide Radium-226.

Main ionising radiations α, β, γ.

Half life 1602 years.

Hazard External irradiation of the body, including possibly more-sensitive organs such asthe eyes. Internal irradiation of the body arising from substances which have enteredby inhalation, by absorption through the skin, by ingestion or through wounds.

Risk assessment The residual risk is low with the control measures in place.

Control measures Always follow the standard operating procedures for the use of radioactivesources.

During use This source should be kept in its cloud chamber. It should not be touched.

Inspection Annually and after use by students. The source (left in the cloud chamber) should bechecked for damage, keeping at least 20 cm from the eyes.

Leak test of source Annually or if damage is suspected. The outer surfaces should be tested.

Contamination checkof container

Due to the very small amounts of radon gas emitted from radium sources, the insideof the cloud chamber should be checked annually and decontaminated if necessary.This is also required if leakage is suspected.

Storage and labelling It is usually best not to try to remove the source from this type of cloud cham-ber, because the process can be difficult and may damage the source. Therefore,the whole chamber should be labelled with a radioactive warning sign and stored ina labelled, locked cupboard, preferably near to the main radioactives store. It isnormally best not to keep the whole cloud chamber in the main radioactives store,because it would be difficult to clean if contaminated by other sources. It may alsobe too large to fit in the main store.

Spills A lab coat and disposable gloves should be worn. If a cloud chamber source isdropped, the area on to which it fell must be checked for contamination and decont-aminated if necessary.

Disposal

© CLEAPSS 2008

Can be disposed via the refuse collection, provided the source is grouted into arugged container and the refuse is collected by your local authority’s internal wastecontractor or by an external contractor who operates on contract to your localauthority (even if there is a separate contract for your school).

Information and Model Risk Assessments for Radioactive Sources

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7 Perspex slide source: use, storage & disposalDescription The active substance or foil source is sealed into a

Perspex slide with epoxy resin.Strontium-90, americium-241 and radium-226sources have small holes in the Perspex and thesource is protected with a thin layer of gold.

Typical dimensions (mm) Length 50; width 50; thickness 3.5.

Use Investigation of basic properties of ionising radiations.

Supplier These sources have not been available for many years. The supplier was LabgearLtd (no longer in business). The sealed radionuclide was processed and mountedby Nycomed Amersham.

Radionuclide Cobalt-60 Strontium-90/Yttrium-90

Americium-241

Radium-226

Thorium-232

Main ionising radiations γ (β) β α (γ) α, β, γ β (α)

Original activity kBq (µCi) 37 (1) 37 (1) 185 (5) 3.7 (0.1) 185 (5) 37 (1)

Half life (years) 5.26 28.1 28.1 458 1602 1.4 x 1010

Labgear Code C B E A D F

Hazard External irradiation of the body, including possibly more-sensitive organs such asthe eyes. Internal irradiation of the body arising from substances which haveentered by inhalation, by absorption through the skin, by ingestion or throughwounds.

The radium source has a relatively high beta radiation field and should be handledcarefully, using beta shielding if necessary. It is prudent to shield both sides with10 cm thick plastic when not in immediate use.

Risk assessment The residual risk is low with the control measures in place.

Control measures Always follow the standard operating procedures for the use of radioactivesources.

During use This type of source should be held near the edge and the source kept at least10 cm from the hand; large forceps are ideal. Only one source should be used at atime. Between investigations, the source should be returned to its container.

Inspection Annually and after use by students. The slide should be checked for any signs ofdamage. The most active surface should be viewed indirectly, using a plane mirroron the bench. Never point this surface towards the eye. The resin seal and anyvisible foils should be intact. A record should be kept of any blemishes, particularlyto the foil surface.

Leak test of source Annually or if damage is suspected. The outer surface should be tested, takingcare not to damage the seals over the active material.

Contamination checkof container

Not required unless leakage is suspected. However, due to the very smallamounts of radon gas emitted from radium sources, an annual check should bemade on the containers of these sources, which should be cleaned if necessary.

Storage and labelling The sources may be kept together in a small plastic 35 mm slide box. It is best ifthe radium source is kept in a separate box from the others to preventcontamination from small quantities of radon gas. A 50 mm square, lead absorbershould be placed at each end of the ‘stack’ of sources. Put 10 cm thick plasticblock either side of the radium source. The slide box should be labelled with aradioactive warning sign and kept in the radioactives store.

Spills A lab coat and disposable gloves should be worn. If a source is dropped, the areaon to which it fell must be checked for contamination and decontaminated ifnecessary.

Disposal

© CLEAPSS 2008

No more than one source per week can be disposed via the refuse collection,provided the source is grouted into a rugged container, no source is more than200 kBq ( 5µCi) and the refuse is collected by your local authority’s internal wastecontractor or by an external contractor who operates on contract to your localauthority (even if there is a separate contract for your school).

Information and Model Risk Assessments for Radioactive Sources

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8a Cup source: use, storage & disposalDescription This is the most common type of sealed source used in

educational establishments. The radioactive substance isenclosed in a metal foil and secured at the base of ametal cup by a circlip. Wire mesh covers the open end ofthe cup. A stem is used for handling and mounting.Details of the radionuclide and original activity areusually stamped on the back of the cup, next to the stem.A serial number may be engraved there too. Cupsources are supplied in a small lead pot with a lead lidinside a suitably-labelled, hardwood, storage container.

Typical dimensions (mm) Length 22, diameter 13, stem diameter 4.

Use Investigation of basic properties of ionising radiations.

Supplier Usually Griffin & George or Philip Harris, with radionuclide manufactured currentlyby AEA Technology QSA GmbH but has been Nycomed Amersham and others inthe past. Panax and Nicholson also supplied this type of source. For the Panax S4source (strontium-90) see sheet 8b.

Original activity 3.7 kBq (0.1 µCi) to 370 kBq (10 µCi), depending on type.Most commonly 185 kBq (5 µCi).

Radionuclide Cobalt-60 Strontium-90 Americium-241 Plutonium-239 Radium-226

Main ionising radiations γ (β) β α (γ) α α, β, γ

Half life (years) 5.26 28.1 458 2.44 x 104 1602

Colour code (if present) Green Yellow Brown Blue Red

Hazard External irradiation of the body, including possibly more-sensitive organs such asthe eyes. Internal irradiation of the body arising from substances which have enteredby inhalation, by absorption through the skin, by ingestion or through wounds.

Risk assessment The residual risk is low with the control measures in place.

Control measures Always follow the standard operating procedures for the use of radioactivesources.

During use This type of source should be held by the stem and kept at least 10 cm from thehand; large forceps are ideal. Only one source should be used at a time. Betweeninvestigations, the source should be returned to its container.

Inspection Annually and after use by students. The whole source should be checked for signsof damage. View the most active foil surface using a plane mirror on the bench.Never point the foil surface towards the eye. A record should be kept of any blem-ishes, particularly to the foil surface.

Leak test of source Annually or if damage is suspected. The outer surface should be tested.

Contamination checkof container

Not required unless leakage is suspected. However, due to the very small amountsof radon gas emitted from radium sources, an annual check should be made on thecontainers of these sources, which should be cleaned if necessary.

Storage and labelling The source should be stored in its lead-lined container, labelled with a radioactivewarning sign and kept in the radioactives store.

Spills A lab coat and disposable gloves should be worn. If a source is dropped, the areaon to which it fell must be checked for contamination and decontaminated if necess-ary.

Disposal

© CLEAPSS 2008

No more than one source per week can be disposed via the refuse collection,provided the source is grouted into a rugged container, no source is more than200 kBq ( 5µCi) and the refuse is collected by your local authority’s internal wastecontractor or by an external contractor who operates on contract to your localauthority (even if there is a separate contract for your school).

Information and Model Risk Assessments for Radioactive Sources

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8b Panax source S4: use, storage & disposalDescription This source is a relatively high activity collimated beta

source. The source has a slit which is normally coveredby an close-fitting aluminium cup. The manufacturer didnot put a warning trefoil on the plastic base nor put it intoany special container, so it is easily mistaken for a pieceof apparatus such as an absorber.

Typicaldimensions

50mm x 45mm x 25mm deep (including collimator and metal storage cap)

Use Investigation of deflection of beta radiation by a magnetic field.

Supplier Panax, with strontium-90 foil manufactured by the former Radiochemical Centre. Panaxsupplied this type of source in its SK307 kits.

Originalactivity

330 kBq (9 µCi).

Radionuclide Strontium-90

Main ionisingradiations

β

Half life (years) 28.1

Hazard External irradiation of the body, including possibly more-sensitive organs such as the eyes.Internal irradiation of the body arising from substances which have entered by inhalation, byabsorption through the skin, by ingestion or through wounds.

Riskassessment

The residual risk is low with the control measures in place.

Controlmeasures

Always follow the local rules for the use of radioactive sources.

During use This type of source should be held by the plastic edges. The aluminium cap should beremoved with plastic forceps and the hand not placed in front of the source slit. The aluminiumcap should be replaced directly at the end of the investigation using the source.

Inspection Annually and after use by students. The whole source should be checked for signs of damage.

Leak test ofsource

Annually or if damage is suspected. The outer surface should be tested.

Contaminationcheckof container

Not required unless leakage is suspected.

Storage andlabelling

Put a small radioactivity warning sign directly on the plastic body. The source should be storedin a suitable small container, labelled with a radioactive warning sign and kept in theradioactives store.

Spills A lab coat and disposable gloves should be worn. If a source is dropped, the area on to whichit fell must be checked for contamination and decontaminated if necessary.

Disposal

© CLEAPSS 2008

No more than one source per week can be disposed via the refuse collection, provided thesource is grouted into a rugged container, no source is more than 200 kBq (5 µCi) and therefuse is collected by your local authority’s internal waste contractor or by an externalcontractor who operates on contract to your local authority (even if there is a separate contractfor your school). Although the original source was 333 kBq, the 200 kBq limit will not beexceeded because of the decay of these very old sources.

Information and Model Risk Assessments for Radioactive Sources

52

8c Iso-trak sources (recessed in aluminium rod): use, storage & disposalDescription The source assembly comprises a source

(a sealed stainless steel capsule or a metalfoil or disc) housed in a recess in analuminium rod. The rods are supplied in ametal container, which can hold one(shown in illustration) or more rods.

Typical dimensions Length 85 mm, diameter 12 mm. The source is 8 mm from the end of the rod.

Use Investigation of basic properties of ionising radiations.

Supplier HTSL and Didactic Systems (Leybold Didactic); manufactured in Germany by QSAGlobal / Isotrak (previously AEA Technology)

Original activity 74 kBq (2 µCi). (342 kBq (9 µCi) for a mixed nuclide source)

Radionuclide Cobalt-60 Strontium-90 Americium-241 Sodium-22 Caesium-137

Main ionising radiations γ (β) β α (γ) β+ β

Half life (years) 5.26 28.1 458 2.62 30

Hazard External irradiation of the body, including possibly more-sensitive organs such asthe eyes. Internal irradiation of the body arising from substances which have enteredby inhalation, by absorption through the skin, by ingestion or through wounds.

Risk assessment The residual risk is low with the control measures in place.

Control measures Always follow the standard operating procedures for the use of radioactivesources.

During use This type of source should be held by the non-source end of the aluminium rod withthe source end directed away from the body. Only one source should be used at atime. Between investigations, the source should be returned to its container.

Inspection Annually and after use by students. The whole source should be checked for signsof damage. View the recessed surface using a plane mirror on the bench. Neverpoint the foil surface towards the eye. A record should be kept of any blemishes,particularly to the surface.

Leak test of source Annually or if damage is suspected. The outer surface should be tested, butavoiding contact with the actual surface of the source.

Contamination checkof container

Not required unless leakage is suspected.

Storage and labelling The source should be stored in its metal container, labelled with a radioactivewarning sign and kept in the radioactives store.

Spills A lab coat and disposable gloves should be worn. If a source is dropped, the areaon to which it fell must be checked for contamination and decontaminated if necess-ary.

Disposal

© CLEAPSS 2008

No more than one source per week can be disposed via the refuse collection,provided the source is grouted into a rugged container, no source is more than200 kBq ( 5µCi) and the refuse is collected by your local authority’s internal wastecontractor or by an external contractor who operates on contract to your localauthority (even if there is a separate contract for your school).

53

9a Protactinium generator: use, storage & disposalDescription This is a sealed, thin-walled polypropylene or fluorinated plastic bottle

containing an aqueous solution of acidified uranyl(VI) nitrate beneath an equalvolume of organic solvent. The protactinium generator can be treated as asealed source, provided the cap is not removed. Home-made generators mayneed to be replaced annually, since the organic solvent can soften the plasticbottle or damage the seal in the cap. Commercially-made generators haveproved to be very long-lasting, most remaining in good condition for well over10 years. See sheet 9b for Making Protactinium Generators.

Use When the bottle is shaken, only protactinium passes into the top organic liquid layer. Its decaycan then be investigated by placing a GM tube very close to the organic layer.

Supplier Ready-made by Philip Harris, but has not been available for some years. New version fromScienceScope Ltd, Abington House, 146 London Road West, Bath, BA1 7DD.Many schools make their own, but special procedures must be followed; instructions areprovided on CLEAPSS Recipe Card no. 57. Use a tin-walled fluorinated plastic bottle (eg PFA orFEP polymers). They are much more expensive but have an extremely high resistance tochemical degradation and have a working life well over 10 years.

Original activity Philip Harris version: 44.5 kBq (1.2 µCi). Home-made (30 cm3) version 10 kBq (0.37 µCi)

Radionuclide Uranium-238 Thorium-234 Protactinium-234

Main ionising radns. α β β

Half life 4.5 x 109 years 24 days 72 seconds

Hazard Concentrated hydrochloric acid is CORROSIVE (see CLEAPSS Hazcard 47A);Pentyl ethanoate (amyl acetate) is HARMFUL & FLAMMABLE (see Hazcard 43B);Uranyl(VI) nitrate is VERY TOXIC and RADIOACTIVE (see Hazcard 105).Internal irradiation of the body arising from substances which have entered by inhalation, byabsorption through the skin, by ingestion or through wounds.

Risk assessment The activity is less than a quarter of that of a typical school cup source. The greatest risk is fromcontamination if the bottle leaks or the cap is removed. The residual risk is low with the controlmeasures in place.

Control measures Always follow the standard operating procedures for the use of radioactive sources.

During use The bottle must not be opened in normal use. It should be used in or over a tray (ideallyenamel) to contain the solution in the unlikely event of a spill. The bottle may be held in the hand,but for no longer than necessary. When required, shaking should be gentle and take place overthe tray. Between investigations, the bottle should be returned to its protective, outer plasticcontainer.

Inspection Annually as well as before and after any use. Checks should be made for signs of damage ordeterioration. If the cap is accessible, a check should ensure that it is tight. (Harris generatorshave a seal over the cap.)

Leak test of source Annually or if damage is suspected.It is sufficient to check the container in which the bottle stands. Do not open the bottle.

Contamination checkof outer container

Annually or if leakage is suspected. It is sufficient to check the container in which the bottlestands. Clean if necessary. Contamination means that the bottle may be leaking and furtherinvestigation is required.

Storage andlabelling

The bottle should be labelled on the lower half indicating that it is a radioactive protactiniumgenerator. A label on a cover or a strip of adhesive tape over the cap should state that it must notbe removed. The bottle should be kept upright in a plastic container with tight-fitting lid. Thisshould be labelled with warning signs and full details of the contents and hazards (see section5.8). It should be kept in the radioactives store.

Spills A lab coat, eye protection and disposable plastic gloves should be worn. A spill should becontained with a mineral absorbent and scooped into a bucket with sodium carbonate and water.Detergent should be added and the resulting liquid poured down a toilet to reach a foul-waterdrain. Solids should be rinsed and the empty bottle thoroughly washed out. Solids and bottleshould be transferred to a strong plastic bag, which is tied and put in the refuse. The surfacewhere the spill occurred must be checked for contamination and decontaminated if necessary.

Disposal:

© CLEAPSS 2008

Lab coat, goggles and disposable gloves should be worn. Traditionally, the bottle has beenemptied into half a bucket of water and detergent, which is poured down a toilet and flushedtwice so that the very dilute solution reaches a foul-water drain. The empty bottle should bethoroughly washed out, transferred to a strong plastic bag, tied and put in the refuse. Strictly,now, the contents of the bottle should be poured into a separating (tap) funnel. The lower,radioactive, aqueous layer is run into a beaker and then transferred to the bucket and treated asabove. The upper, non-radioactive, organic layer is then run out into a beaker and transferred tothe general laboratory (organic) waste for eventual collection. The funnel and beakers should bewashed thoroughly with water containing detergent.

54

9b Making a protactinium generatorDescription

1

2

34 The schematic diagram shown is for

information only.

This sheet gives a model risk assessment forthe preparation of a home-made protactiniumgenerator and must be read in conjunctionwith Risk Assessment 9a.

More instructions are given on CLEAPSSRecipe Card 57.

Use See Risk Assessment 9a.

Supplier 30ml Bottle. Ideally a thin-walled fluorinated plastic bottle (usually PFA or FEP polymer).This has high resistance to chemical degradation and could have a working life of around 10years. Polypropylene bottles are less resistant to the organic solvent. Bottles made from otherplastics will soften very rapidly and must not be used.Uranyl nitrate is available from very few suppliers. Ideally, existing stocks should be sharedbetween schools (with the prior agreement of the RPO or RPA).Concentrated hydrochloric acid and pentyl ethanoate are standard laboratory chemicals.Self-amalgamating insulating tape, to make the cap more tamper-resistant. This is availablefrom electrical suppliers.

Original activity 1.5 g of uranyl nitrate has an activity of about 10 kBq (0.37 µCi).This is much less than that of a typical school cup source.

Radionuclide Uranium-238 Thorium-234 Protactinium-234

Main ionisingradiations

α β β

Half life 4.5 x 109 years 24 days 72 seconds

Hazard Uranyl(VI) nitrate is VERY TOXIC and RADIOACTIVE(see CLEAPSS Hazcard 105). The radiation hazard is internal irradiation of the body, arisingfrom substances which have entered by inhalation, by absorption through the skin, by ingestionor through wounds.Concentrated hydrochloric acid is CORROSIVE(see CLEAPSS Hazcard 47A).Pentyl ethanoate (amyl acetate) is HARMFUL & FLAMMABLE(see CLEAPSS Hazcard 43B).

Risk assessment The main risks are from radioactive contamination or burns from the hydrochloric acid. The RPS(Schools) must be certain that the teacher or technician carrying out the procedure iscompetent. The residual risk is low with the control measures in place.

Control measures Follow the control measures below, when preparing a protactinium generator.

During preparation Check bottle for damage or leaks before use. Fill with distilled water, tighten cap and squeezegently. Empty the bottle. Do not use any bottle, which appears to leak.

Wear labcoat, eye protection and disposable plastic gloves, throughout the procedure.

Use a sheet of filter paper on the balance pan, beneath the empty bottle. Tare the balanceand weigh uranyl nitrate directly into the bottle. Use the filter paper to return any spilt uranylnitrate to the stock container.

Work in a glass or enamel tray, whilst adding liquids, to catch any spills.

Inspection The bottle must be checked for any physical damage, once the generator as been prepared.

Leak test of source A leak test for radioactivity should be carried out, once the generator has been prepared.

Contamination checkof outer container

See Risk Assessment 9a.

Storage andlabelling

See Risk Assessment 9a.

Spills See Risk Assessment 9a.

Disposal:© CLEAPSS 2008

See Risk Assessment 9a.

55

10 Radon-220 (thoron) generator (powder version): use, storage & disposal(Some employers do not permit its use.)

Description: Originally called a thoron generator, but more correctly termed a radon-220gas generator. A polythene squeeze bottle containing about 20 g of a thorium compound inpowder form (usually thorium hydroxide or carbonate). Very small quantities of radon-220gas are produced by the radioactive decay series of thorium. In order to let radon gas out,but keep the powder in, two discs of chamois leather are fitted in the cap to act as a filter.

In some older designs, the powder was in a muslin bag. When the generator is not in use a Mohr clip on a single rubber tubeprevents gas escaping. Older generators had alternative, unsatisfactory filters and more complex pipework, which should bedisposed of carefully & replaced. This type of radon generator has not been available for many years.Recently radon-220 generators using gas mantles became available: see sheet 11.

Use: When the bottle is squeezed, radon gas travels along the tube into a port on a separate, closed, ionisation chamber, wherethe short half life of the gas can be determined. Any unused port on the chamber must be made gas tight, eg, by fitting a smallparty balloon over the port and tying it tightly. Unsealed systems should not be used.

Supplier: The original generators were supplied ready-made by Panax, Griffin and Harris. They have been unavailable topurchase for many years. Some schools have prepared their own generators using polythene wash bottles.

Original activity: typically 64 kBq (1.7 µCi).

Radionuclides Thorium-232 Radium-228 Actinium-228 Thorium-228 Radium-224 Radon-220

Main radiations α β β α α α

Half life 1.4 x 1010 years 6.7 years 1.1 hours 1.9 years 3.6 days 52 seconds

Hazard Thorium compounds are VERY TOXIC and RADIOACTIVE (see CLEAPSS Hazcard 101). Internalirradiation of the body arising from substances which have entered by inhalation, by absorption through theskin, by ingestion or through wounds.

Risk assessment: The activity is usually less than half that of a typical school cup source. Radon gas should not escape if theapparatus is used carefully but, if it did, the concentration in the air would be extremely low. The greatest risk is from inhalation ofthorium dust, which is an alpha-emitter. Extreme care must be taken if the bottle splits or the top needs to be removed.The residual risk is low with the control measures in place. However, stored or used incorrectly, a radon generator can present agreater risk than other sources commonly used in schools. Some employers do not permit its use and this must berespected. Science department managers and employers need to satisfy themselves that staff are fully aware of the hazardsand that the control measures given below are in place. If this is not the case, and cannot be addressed, the source should bedisposed of.Some RPAs believe that there are safer alternative methods for half-life investigations, see Sheets 9a, 11 and 13.

Controlmeasures

Always follow the standard operating procedures for the use of radioactive sources. Apart from withinradon-220 generators, thorium compounds are outside the Standard School Holding.

During use The bottle must not be opened. It should be used in a tray to catch the thorium compound in the unlikelyevent of a spill. The bottle should not be held for longer than necessary and the clip only removed when thetube is connected to a closed container. An extremely small volume of radon gas is required, so the bottleshould only be squeezed very gently two or three times. After use, the generator should be left connected tothe closed container for at least an hour to ensure that the radioactive gas has decayed.It is necessary to wait for 4 or 5 days after use before opening the ionisation chamber, to allow theminute amounts of deposited solid daughter products to decay.

Inspection Annually as well as before and after any use. If the bottle, filter or tubing show any sign of deterioration ordamage, that component must be replaced. If the bottle needs to be opened, special precautions, as for spillsand disposal below, must be followed. The inspection should include the inside of the ionisation chamber andtubing (where visible), to ensure that the filter keeps the powder in the bottle.

Leak test ofsource

Annually or if damage is suspected. Do not open the bottle. The outer surfaces and the cap should be leaktested. The inside of the ionisation chamber should be contamination checked.

Contaminationcheck ofcontainer

The plastic storage bag should be checked annually and replaced if necessary. Contamination means that thebottle may be leaking and further investigation is required.

Storage and labelling: The squeeze bottle should have a small label indicating that it is a radioactive radon generator.Another label close to the cap should make it clear that the top must not be removed. The bottle should be kept in a strong, self-sealing, plastic bag This should be fully labelled (see section 5.7) and kept in the radioactives store.

Spills: must be treated as a major incident. Lab coat, toxic dust mask (European Standard EN149 category FFP3) & disposableplastic gloves must be worn. The spill and the surrounding area must be covered immediately with damp tissues or paper towelsand air disturbance avoided Once the spill is covered, the room should be evacuated and the RPS (Schools) consulted. If thespill is small, or within a tray, it should be possible to clear it up and to decontaminate very carefully. If the spill is larger or morewidespread, windows should be closed, the room locked and the RPA or CLEAPSS consulted. Decontamination may requireprofessional expertise and more-sensitive contamination monitoring instruments.

Disposal

© CLEAPSS 2008

Disposal of up to 100 g thorium compounds per day via refuse collection is possible provided that theunopened bottle is grouted into rugged container and the refuse is collected by your local authority’s internalwaste contractor or by an external contractor who operates on contract to your local authority even if there is aseparate contract for your school, or, if it is a non-local authority contractor the refuse goes to landfill. The RPAshould be consulted.

56

11 Radon-220 (thoron) generator – gas mantle version: use, storage &disposal

Description: A polythene squeeze bottle containing thoriated gas mantles(mantles impregnated with thorium oxide). Very smallquantities of radon-220 gas are produced by the radioactivedecay series of thorium. When the generator is not in use aMohr clip on a single rubber tube prevents gas escaping. Inthe version manufactured by Cooknell, the radon generatoris connected to an ionisation chamber and integral verysensitive picoammeter.

Use When the bottle is squeezed, radon gas travels along the tube into a port on a separate, closed,ionisation chamber, where the short half life of the gas can be determined. Any unused port on thechamber must be made gas tight, eg, by fitting a small party balloon over the port and tying it tightly.Unsealed systems should not be used.

Supplier Cooknell Electronics Ltd, 17 Cambridge Road. Granby Industrial Estate. Weymouth. DT4 9TJ

Originalactivity

Typically 6 kBq (0.16 µCi)

Radio-nuclides

Thorium-232 Radium-228 Actinium-228 Thorium-228 Radium-224 Radon-220

Mainradiations

α β β α α α

Half life 1.4 x 1010 years 6.7 years 1.1 hours 1.9 years 3.6 days 52 seconds

Hazard Thorium compounds are VERY TOXIC and RADIOACTIVE (see CLEAPSS Hazcard 101). Internalirradiation of the body arising from substances which have entered by inhalation, by absorption throughthe skin, by ingestion or through wounds.

Riskassessment

The thorium is impregnated into the gas mantle fabric so the release of any significant thorium dust willbe unlikely. Radon gas should not escape if the apparatus is used carefully but, if it did, theconcentration in the air would be extremely low. Caution is needed if the bottle splits or the top needs tobe removed as there can be fragments of mantle which could be released. The residual risk is low with thecontrol measures in place.

Controlmeasures

Always follow the local rules for the use of radioactive sources.

Gas mantles are regarded as low level radioactive artefacts.

During use The bottle must not be opened. An extremely small volume of radon gas is required, so the bottle shouldonly be squeezed very gently two or three times. The Cooknell ionisation chamber is sealed and shouldnot be opened.

Inspection Annually as well as before and after any use. If the bottle, filter or tubing show any sign of deteriorationor damage, that component must be replaced. If the bottle needs to be opened, special precautions, asfor spills and disposal below, must be followed.

Leak test ofsource

Annually or if damage is suspected. Do not open the bottle. The outer surfaces and the cap should beleak tested.

Contaminationcheck ofcontainer

Not required unless fragments of mantle are suspected of escaping the bottle. If so, the plastic storagebag should be checked and replaced if necessary.

Storage andlabelling

With the clip closed, the tube and bottle is disconnected from the apparatus. The bottle with tube shouldbe stored in a strong, self-sealing, plastic bag and kept in the radioactives store. The bottle should have asmall label indicating that it contains thoriated gas mantles for generating radon. Another label close tothe cap should make it clear that the top must not be removed.

Spills If the bottle breaks, the gas mantles may release a few fragments, so care is needed. Wear a lab coat,toxic dust mask (European Standard EN149 category FFP3) and disposable plastic gloves. Carefully pickup the bottle and gas mantles with a tissue and place them in a bag. Use sticky tape and dab the bencharea to pick up any fragments. Carefully check the area with a GM tube and counter to ensure it is clearof all contamination.

Disposal

© CLEAPSS 2008

Gas mantles can be disposed of via refuse collection provided that your refuse is collected by your localauthority’s internal waste contractor or by an external contractor who operates on contract to your localauthority even if there is a separate contract for your school, or, if it is a non-local authority contractor therefuse goes to landfill.

57

12 Gas mantles (impregnated with thorium compounds): use, storage &disposal

Description Gas mantles, intended for use with camping gas lamps andsimilar, comprise a cotton or silk fabric impregnated with variouscompounds (to increase luminosity). When first used in a lamp, thefabric burns away leaving a fragile mesh of ash. Some mantlesuse thorium compounds as these are considered to give the bestluminosity. The gas mantle does NOT need to be burnt and formost purposes can be kept and used in the plastic or cellophaneenvelope in which it is supplied.

Use To show that ‘domestic’ objects may be naturally radioactive. A piece of apparatus has recently beendeveloped in which several gas mantles are contained in a sealed chamber. See Model RiskAssessment 11.

Supplier Gas mantles can be obtained from hardware or camping shops. An apparatus for half-lifedetermination is now available, see Model Risk Assessment 11.

Original activity Of one mantle, typically 1 kBq (0.03 µCi)

Radionuclides Thorium-232 Radium-228 Actinium-228 Thorium-228 Radium-224 Radon-220

Main radiations α β β α α α

Half life 1.4 x 1010 years 6.7 years 1.1 hours 1.9 years 3.6 days 52 seconds

Hazard Thorium compounds are VERY TOXIC and RADIOACTIVE (see CLEAPSS Hazcard 101). Internalirradiation of the body arises from substances which have entered by inhalation, by absorptionthrough the skin, by ingestion or through wounds.

Riskassessment

Gas mantles are readily available to the general public. The concentration of radon in the air wouldbe extremely low. Certainly before the mantle is burnt, there is little risk of inhalation of thorium dust,because the thorium is impregnated into the fabric of the mantle. The residual risk is low with thecontrol measures in place.

Controlmeasures

Always follow the standard operating procedures for the use of radioactive sources.

Gas mantles are regarded as low level radioactive artefacts.

During use Keep the gas mantles in a strong, self-sealing plastic bag.

Inspection Check that the mantle is in good condition and not fraying significantly.

Leak test ofsource

Not applicable.

Contaminationcheck of container

Not required unless fragments of mantle are suspected of escaping the bag.

Storage andlabelling:

Gas mantles should be put in a strong, self-sealing, plastic bag, labelled with a radioactive warningsign and kept in the radioactives store. Alternatively, gas mantles may be kept in the half-lifeapparatus.

Spills: A lab coat and disposable gloves should be worn. If a gas mantle is dropped, it is most unlikely thatany radioactive spill will occur. The area must be checked for contamination and decontaminated ifnecessary.

Disposal© CLEAPSS 2008

In the refuse if it is collected by your local authority’s internal waste contractor or by an externalcontractor who operates on contract to your local authority even if there is a separate contract foryour school, or, if it is a non-local authority contractor, the refuse goes to landfill.

58

13 Caesium-137 elution source: use, storage & disposalNote: the versions of this source above 37 kBq are NOT regarded as part of the Standard School Holding

Description The Isotrak generator comprises a small plastic cylinder containing 33 kBq of caesium-137 absorbed in an ion exchange resin. When the system is eluted (ie, a specialsolution is passed through it using a syringe), the decay product barium-137m isremoved from the generator in the solution. This allows the barium-137m decay to bemonitored with a GM tube. The eluant (low hazard) is a very pure, slightly acidicsolution of sodium chloride.

Typical dimensions 40mm diameter x 60mm long (including 2 plastic storage caps)

Use The generator will yield up to 1000 small liquid samples containing the barium-137m isotope. The shorthalf-life of this can be easily measured.

Supplier QSA-Global, Isotrak range, 33 kBq, distributed in the UK by High Technology sources Ltd. Note that the370 kBq types from QSA-Global and from Spectrum Techniques (USA) are not recommended as theyboth exceed 37 kBq (and hence disposal would be very expensive).

Original activity Typically 33 kBq (0.9 µCi)

Radio-nuclides Caesium-137 Barium-137m

Main radiations β γ and conversion electrons

Half life 30 years 2.6 minutes

Hazard External irradiation of the body, including possibly more-sensitive organs such as the eyes. Internalirradiation of the body arising from substances which have entered by inhalation, by absorption throughthe skin, by ingestion or through wounds.

Risk assessment The equivalent dose rate near the surface of the generator is about 2 µSv hr-1. The dose rate from theeluate in the bottle is similarly low, and in the short time the generator and eluate are handled, theequivalent dose on the hands will be negligible. If the eluate were to be spilled on the skin and it took 10minutes to notice and wash it off, then assuming the activity of the eluate was 33 kBq and the contactarea 10 cm2 with no protection from gloves or clothing the initial equivalent dose rate to the skin would beabout 100 µSv hr-1, so the equivalent dose to the skin in 10 minutes (integrating to allow for the shorthalf-life) is about 6 µSv.There is a risk arising from undesirable release of caesium-137 into the eluate. Data from QSA-Globalshows that the bleed-through using the eluant provided with the generator is very low, less than 50 Bqcm-3. In tests carried out by CLEAPSS, there was no detectable caesium-137 in the eluate. There is apossibility of bleed-through exceeding 50 Bq cm-3 if an inappropriate fluent is used. Note that an earlierdesign of this type of generator used a different fluent which is completely unsuitable for the currentIsotrak design.The residual risk is low with the control measures in place.

Control measures Always follow the standard operating procedures for the use of radioactive sources.

Only staff who have been specially trained for use of this source should handle it.

During use Wear disposable gloves, a lab coat and eye protection. Work over a drip tray lined with absorbentmaterial. Check that the correct fluent (ie, as supplied with the source) is used.

After use After at least 30 minutes, the eluate can be poured down the drain and flushed with several litres ofwater. After at least 30 minutes, the disposable gloves and paper liner can be placed in a plastic bag,sealed with tape and placed (unlabelled) in the refuse as very low level waste.

Records The record should list the name(s) of anyone handling the source on a particular occasion and thevolume eluted.

Inspection Annually as well as before and after any use. Checks should be made for signs of damage ordeterioration.

Leak test of source Annually or if damage is suspected.

Contaminationcheck of container

Annually or if leakage is suspected. It is sufficient to check container in which the source is kept. Clean ifnecessary. Contamination means that the source may be leaking and further investigation is required.

Storage &labelling:

The source should be stored in its original container, labelled with a radioactive warning sign and kept inthe radioactives store.

Spills: A lab coat, disposable and eye protection should be worn. If a source is dropped, or the fluent spilt, thearea on to which it fell must be checked for contamination and decontaminated if necessary.

Disposal© CLEAPSS 2008

Disposal of the 33 kBq source can be made under the Schools Exemption Order (but a 370 kBq sourcecould not be). This should be discussed with the RPA (via the RPO for schools subscribing to theCLEAPSS RPA Service).

59

14 Domestic glassware and ceramic items, coloured with radioactivecompounds: use, storage & disposal

Description Glass and ceramic items withradioactive compounds added(eg, uranium oxide). Theseinclude green Vaseline glass andthe red/orange glaze onFiestaware crockery.

Typical dimensions (mm) Various

Use To show that some domestic items are radioactive. Using a GM tube close to theitem, an increased count is demonstrated, compared with background radiation.Vaseline glass may also be shown to fluoresce under ultraviolet radiation (see otherCLEAPSS guidance on the safe use of ultraviolet).

Radionuclide Uranium-238 and others

Supplier Originally manufactured by glassworks and potteries throughout the world, the nameFiesta® is a trademark. However, the generic word Fiestaware is now often used todescribe any solid colour crockery. Products of this type are now coloured usingdifferent compounds, which are not radioactive. However, the older radioactiveitems may still be obtained second-hand.

Original activity Weak. Vaseline glass is typically less than 2% uranium by mass. The glaze used onradioactive Fiestaware is typically less than 15% uranium by mass.

Main ionising radiations α, β, γ (include in emissions from the decay products of Uranium-238)

Half life Long, eg, uranium-238 4.5 x 109 years

Hazard External irradiation of the body, including possibly more-sensitive organs such asthe eyes. Internal irradiations of the body arising from substances which haveentered by inhalation, by absorption through the skin, by ingestion or throughwounds. Uranium compounds are also toxic.

Risk assessment The residual risk is low with the control measures in place.

Control measures Always follow the standard operating procedures for the use of radioactivesources.

During use Use in a tray, to contain fragments in the event of damage. This also allows directhandling time to be kept to a minimum.

Inspection Annually as well as before and after any use.Items, which are chipped or cracked, should be disposed of.

Leak test of source Annually or if damage is suspected.The outer surfaces of the item should be tested.

Contamination checkof container

Not required unless leakage is suspected.

Storage and labelling These items may be kept in protective packaging, eg, bubble wrap, inside a sturdycontainer, or strong plastic bag. Use a label with a radioactive warning sign and thewords “ceramic/glass-ware with low radioactive content”.

Spills If such a glass or ceramic item is dropped and breaks, by far the greatest hazard willbe from sharp edges. However care must also be taken to avoid contamination fromthe low amounts of radioactive material present. Wear lab coat, dust mask(European Standard EN149 category FFP3) and disposable gloves. Use forceps totransfer larger broken fragments on to several layers of paper. Collect smallerfragments and dust using wide sticky tape and place in the paper. Wrap fragmentsand bind paper with sticky tape. Seal in a sturdy plastic bag and place in the normalwaste. Check area of spill, with a GM tube, to ensure that it is free of contamination,cleaning with moist towels or tissue as necessary.

Disposal

© CLEAPSS 2008

These items should be wrapped in thick paper, put in a sturdy plastic bag. They maythen be disposed of via a refuse collection, provided that your refuse is collected byyour local authority’s internal waste contractor or by an external contractor whooperates on contract to your local authority even if there is a separate contract foryour school, or, if it is a non-local authority contractor the refuse goes to landfill.

60

15 Thoriated tungsten welding rod: use, storage & disposalDescription Thoriated tungsten electrodes are intended

for TIG (Tungsten Inert Gas) welding andtypically contain about 1 or 2% thoriumoxide. (Rods with a red tip have 2%)

Typicaldimensions

3 mm (diameter), 150 mm length. Other diameters are available.

Use Can be used in a diffusion (Taylor) cloud chamber, in place of the small radium paint sourceswhich are no longer easy to obtain. Such cloud chambers supplied by Ideas for Education havea 3.5 mm diameter hole, intended for inserting the source. The cloud chamber will need to bemodified by having an additional 3.5 mm hole drilled directly opposite. The rod is held in place byinserting it into a bung or cork at each end.

Supplier SWP brand, type WT20, (conforming to BS EN ISO 26848: 2004) commonly available in packsof 10 from welding supplies shops but can usually be purchased individually. (Details of supplierscan be obtained from www.specialisedwelding.co.uk).

Originalactivity

About 3.2 kBq

Radionuclides Thorium-232 Radium-228 Actinium-228 Thorium-228 Radium-224 Radon-220

Mainradiations

α β β α α α

Half life 1.4 x 1010

years6.7 years 1.1 hours 1.9 years 3.6 days 52 seconds

Hazard Thorium compounds are VERY TOXIC and RADIOACTIVE (see CLEAPSS Hazcard 101). Internalirradiation of the body arises from substances which have entered by inhalation, by absorption throughthe skin, by ingestion or through wounds.

Riskassessment

The rods are readily available to the general public. They are conditionally exempt from theRadioactive Substances Act by the Radioactive Substances (Uranium and Thorium) ExemptionOrder 1962. The surface equivalent dose rate is very low, a few microsieverts per hour. Thethorium is evenly dispersed throughout the rod (during manufacture, tungsten and thorium oxidepowder are sintered into a metal alloy rod and the thorium is firmly bound into the metal). It isalmost inconceivable that thorium could be released even if the rod were roughly handled. (Smallamounts of thorium are released when grinding the electrode or to a lesser extent duringwelding.) The residual risk is low with the control measures in place.

Controlmeasures

Always follow the standard operating procedures for the use of radioactive sources.

During use Thoriated tungsten electrodes are regarded as low level radioactive artefacts.

Inspection Check that the rod surface is clean and free from obvious defect.

Leak test ofsource

A simple wipe test (using dry filter paper) can be performed, counting for 100 seconds; a count ofdouble the background should be treated as suspicious.

Contaminationcheckof container

Not required.

Storage andlabelling

Remove from the cloud chambers and keep with other radioactive sources in the secure store (inthe plastic storage case in which they are normally supplied)

Spills Due to the design it is almost inconceivable that thorium oxide would be released even if the rodwere broken.

Disposal

© CLEAPSS 2008

In the refuse if it is collected by your local authority’s internal waste contractor or by an externalcontractor who operates on contract to your local authority even if there is a separate contract foryour school, or, if it is a non-local authority contractor, the refuse goes to landfill.

61

Part CFurther Guidance for Radiation Protection

Supervisors (Schools)8 Emergencies

8.1 Spills and decontaminationWork with radioactive sources within the Standard School Holding rarely gives rise to aradioactive spill, ie, an incident in which a radioactive substance contaminates theworking area. However, if any source is dropped, including the very common cupsource, the surface on to which it fell must be checked for radioactive contamination(even if no spill is visible).It is wise to make provision for dealing quickly, safely and efficiently with any spillsthat may occur. This provision should form part of the risk assessment for the wholeactivity; see section 7 for model risk assessments specific to most types of sources.The RPS (Schools) must ensure that all members of staff using sources are familiar withthe Standard Operating Procedures, which are elaborated on below. All spills involvingradioactive material must be reported to the RPS (Schools) as soon as possible. If theRPS (Schools) is available, it may be appropriate for him or her to oversee the clear-upprocess. In extremely rare circumstances, where a spill is large or widespread,containment measures should be taken (see below), access restricted and CLEAPSScontacted immediately (or the RPA, either directly or via the RPO for local authoritiessubscribing to the CLEAPSS service). It would be wise to report any spill to the RPA,(via the RPO for local authorities subscribing to the CLEAPSS service).

8.1.1 Avoiding spillsNormal working practices should be designed to:

avoid a spill in the first place; limit the extent of any spill; make it easier to clear up if a spill does occur.

For example, it is most important that the protactinium generator and the radon-220(thoron) generator are carefully inspected for deterioration or damage before and afteruse. The protactinium generator and the radon-220 generator with thorium in powderform should always be used over a suitable tray.

8.1.2 Anticipating a spillAll science departments should have one or more chemical spill kits readily available.In addition to the items in the normal CLEAPSS spill kit1, the following items must beavailable.

Disposable gloves (preferably nitrile). A pack of soft paper towels or tissues. A pack of filter papers.

1 See CLEAPSS Laboratory Handbook section 7.7 for information about chemical spills, including details

of spill kits.

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A disposable FFP3 dust mask1 (where powders, eg, thorium compounds arepresent).

A working GM tube and counter (scaler).

8.1.3 Action to be taken following a spill

Personal protection

Where unsealed radioactive substances are present, it is essential to wear a lab coat,disposable gloves (and a disposable dust mask if items containing fine powders, suchas thorium compounds, are involved). If a protactinium generator containinghydrochloric acid is spilt, eye protection (goggles) will also be required.Thorough personal washing is, of course, vital after dealing with any spill. This shouldbe carried out at a sink in the area where the spill occurred, to avoid any possibility ofspreading contamination to other areas. If there is any possibility that a lab coat, orother item of clothing, has been contaminated, it should be washed separately fromother items before normal laundering. Significantly-contaminated items should besealed in strong plastic bags and CLEAPSS consulted (or the RPA, via the RPO in localauthorities subscribing to the CLEAPSS scheme).

Containment

The most important and immediate action after a spill is to stop the radioactivesubstance (and any other hazardous material) from spreading any further. The actiontaken will depend on the type of spill. Do not use methods that will give rise to dust oraerosols (hence avoid the use of a dustpan and brush).

Evacuate students and non-essential personnel from the area. Small amounts of crystalline materials (such as uranyl nitrate) can be brushed care-

fully on to filter paper using a tissue and returned to an appropriate container. Spilt liquids should be covered with a mineral absorbent (or tissues for very

small quantities). Spilt powders (eg, thorium compounds) and the area surrounding them should

be covered with damp tissues or paper towels and air disturbance kept to a min-imum.

Containment will be much easier if the spill has occurred into a tray. Any area whichmay be contaminated and could pose a hazard to others must be labelled and accessrestricted, if appropriate.

Clearing up and disposal

Once a spill has been contained, clearing up should begin as soon as is practicable (eg,immediately after the lesson in which the spill occurred). Students should not be pres-ent while this takes place. In the extremely unlikely event of a larger or widespreadspill (particularly if a fine powder, such as a thorium compound, is involved) closewindows, lock the room and consult CLEAPSS or the RPA (via the RPO in localauthorities subscribing to the CLEAPSS scheme), so that the situation can be assessedbefore proceeding. For example, it may be necessary to use more-sensitivecontamination-monitoring instruments than are normally available in the school.

1 Toxic dust mask (half-mask respirator), European Standard EN149 category FFP3, eg, RS, stock no.

287-2706.

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However, in most circumstances, the spill will be small. The area should initially becleaned with soft paper towels or tissues (held by forceps or tongs) and moistened withwater or a very dilute detergent solution. The cleaning process should always comm-ence from the outer extent of the spill and proceed towards the centre.Used paper, gloves, dust masks and small amounts of mineral absorbent, whether ornot likely to be contaminated, should be placed in a strong plastic bag. The bag is tiedfor disposal as very low-level waste; see section 11.3.1.Larger quantities of mineral absorbent should be scooped into a bucket and washed inwater. If the mineral absorbent contained acid, sodium carbonate should be added. Ifthere are traces of pentyl ethanoate (amyl acetate) solvent, detergent should be added.The resulting liquid is poured down a toilet (on mains drainage) which is flushedtwice; the damp mineral absorbent should be placed in a strong plastic bag, which istied for disposal as very low-level waste; see section 11.3.1. Strictly, if the liquidcontained significant amounts of pentyl ethanoate (amyl acetate) solvent, this should beseparated by pouring into a separating (tap) funnel. The lower, radioactive, aqueouslayer is run into a beaker and then transferred to the bucket and treated as above. Theupper, non-radioactive, organic layer is then run out into a beaker and transferred tothe general laboratory (organic) waste for eventual collection.A record should be made (in the Radioactive Source Use Log, see section 4.1.2) of anysignificant events; include the date, area, etc of any spill.

Checking for contamination

After a spill has occurred and has been cleared up, the affected area will need to bechecked for contamination. Contamination may not be visible, so a check must be madefor radioactivity. The GM tube should be very slowly scanned over the area, keepingthe end window within 5 mm of the affected surface without touching it. Any regionsof apparently increased count rate over background should be investigated in moredetail. The GM tube could be supported close to the surface, using a clamp and stand(resting the base on an uncontaminated surface). If a 2 minute reading of the activity ofa suspect area reveals a count of more than 1.5 times background, more cleaning will berequired using tissues and a detergent solution. If contamination appears to persist, a10 minute comparison of the count of the affected surface and the background shouldbe made to ensure the effect of random variations are minimal. If the RPS (Schools) hasany doubt about the success of the clean up, the area must be protected, accessrestricted and appropriate warning notices put in place. CLEAPSS or the RPA (via theRPO in local authorities subscribing to the CLEAPSS scheme) should then be contactedfor further advice1.

8.1.4 Checking a source after a spillAfter being dropped or other event that may have damaged its integrity, a radioactivesource must be thoroughly inspected, and leak tested if damage is suspected. Theprocedure is similar to that given in section 4.2.2.

1 There is a requirement in the Radioactive Substances (Schools, etc) Exemption Order (Northern Ireland)

1963 to notify the Chief Inspector of the Northern Ireland Environment and Heritage Service if thereare reasonable grounds for believing or suspecting any material has become detached or has escapedfrom a source.

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8.2 Misplacement or loss of a radioactive sourceWhen radioactive sources are not in use, secure storage should be ensured at all times.Problems tend to arise when schools or colleges are being merged, closed orrefurbished. The loss of certain types of sources requires formal reporting to the HSEforthwith.If all movements of sources are recorded accurately in the Use Log, the chance of asource being lost is very small. However, if a source is not where it should be, the RPS(Schools) should check that it has not been:

returned to the wrong store; left inside the piece of equipment within which it was last used; temporarily removed to another area; placed with waste for disposal.

Use a torch to check in dark corners. Completely empty the radioactives cupboard. Ifnecessary, members may consult CLEAPSS for suggestions. We emphasise theimportance of checking and double-checking. Call the source misplaced until you arereally sure it is lost. One source was reported lost to the HSE but on being checked athird time was found at the back of the top shelf of the radioactives store, where itcould not easily be seen, except by bending down.If the source cannot be found, someone in the establishment, usually the RPS (Schools),must inform the RPA (via the RPO, for local authorities subscribing via the CLEAPSSservice). If it is suspected that the source has been removed unlawfully from thepremises, the Head Teacher/Principal, in consultation with the RPA, will need toinform the police. Once the loss is confirmed, the RPA will tell the school to inform theEnvironment Agency and Health and Safety Executive1 if necessary. The loss must bereported forthwith and the radiation employer will probably be required to conduct aninvestigation.The enforcing agencies take a very dim view of source loss and very large fines havebeen levied. Managers and staff in schools and colleges should take all possible steps toensure that this cannot happen.

9 Obtaining radioactive substances

9.1 What sources can schools use?

9.1.1 Is approval needed?The Radioactive Substances Act 1993 controls the acquisition and disposal of allradioactive substances. Fortunately, Exemption Orders mean that, provided certainconditions are met, schools and colleges are not required to register their holding ofradioactive sources with the Environment Agency and are not required to pay anyregistration fees. The Exemption Orders are currently being reviewed (August 2008)and some existing anomalies may be removed. In cases of difficulty, member schoolsand colleges should contact CLEAPSS.

1 In Northern Ireland, the Chief Inspector of the Northern Ireland Environment and Heritage Service

and the Health and Safety Inspectorate in Northern Ireland.

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Until recently, other legislation1 meant that each maintained (state) school had to haveauthorisation from its government education department to use radioactive substanceswith an activity above a very low specified amount. Such permission was granted bythe issue of a Letter of Authorisation (or Approval). Some independent schools andcolleges chose to apply for, and successfully obtained, such letters from governmenteducation departments, although there was no requirement to do this in recent years.However, so far as England is concerned, this legislation was repealed in 20082 andhence it is no longer possible to obtain such letters of authorisation although existingones should be kept on file as part of the source history. In Wales, the regulations arecurrently retained. Independent schools and colleges have sometimes found it difficultto persuade some suppliers that no Letter of Authorisation was needed (despite theDfES writing about this to the main suppliers) and the differing requirements inEngland and Wales may increase the uncertainty. Hence CLEAPSS has drafted asample letter which can be copied and customised, see section 5.6. In case of difficulty,contact CLEAPSS.The 2001 edition of this guide had a considerable focus on how to comply with therequirements of the authorisation system. That has now gone, although the advice hereremains very similar, because it continues to maintain a sensible balance between thevery small risks of using a few low activity sources under controlled conditions and theeducational advantages of doing so.Because responsibility for notifying the HSE rests with the employer (see section2.1), local authority schools should inform their employer before acquiring newradioactive sources. Some employers may provide a form to complete.

9.1.2 Limits set by the Exemption OrdersThere are a number of Exemption Orders made under the Radioactive Substances Act, ofwhich the Radioactive Substances (Schools, etc.) Exemption Order is only one. Most of theothers are quite general and apply to schools as to everyone else and in fact most of thework in schools would be covered by these more general Exemption Orders. Thesemore general Orders would allow schools to hold:

• Most of the sealed sources used in schools3;• Up to 2 kg in total or uranium and thorium compounds4;• Naturally radioactive rock specimens5;• Consumer products such as gas mantles and smoke detectors;• Radio-luminised watches and clocks not exceeding specified activities of

radium, promethium or tritium6.

1 In England and Wales, the Education (Schools and Further and Higher Education) Regulations 1989.2 The Education (Hazardous Equipment and Material in Schools) (Removal of Restrictions on Use) (England)

Regulations, 2008.3 Radioactive Substances (Testing Instruments) Exemption Order 2006 [or the Radioactive Substances (Testing

Instruments) Exemption Order (Northern Ireland) 1986].4 The Radioactive Substances (Prepared Uranium and Thorium Compounds) Exemption Order 1962 [or

Radioactive Substances (Prepared Uranium and Thorium Compounds) Exemption Order (NI) 1962].5 The Radioactive Substances (Geological Specimens) Exemption Order 1962 [or the Radioactive Substances

(Geological Specimens) Exemption Order (Northern Ireland) 1962].6 The Radioactive Substances (Clocks and Watches) (England and Wales) Regulations 2001 [or the Radioactive

Substances (Basic Safety Standard) Regulations (Northern Ireland) 2003].

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The Schools etc Exemption Order identifies the types of radio-active sources that may beused in schools. It allows schools to hold up to: 148 MBq (4 mCi) of sealed sources1; 74 MBq (2 mCi) of unsealed sources (but not strontium-90 and alpha-emitters).

These limits are far beyond what would ever be needed or justified for normal scienceteaching.A school wanting to do work not covered by any Exemption Order would need toregister with the Environment Agency in England and Wales2, which is expensive.Some officers of the Environment Agency have suggested that independent schools areno longer covered by the Schools Exemption etc Order, because, as a result of changingeducation legislation, they are no longer “recognised as efficient”. If a CLEAPSSmember finds itself in this position, and is not able to use any other Exemption Orders,please contact the CLEAPSS Helpline for further advice. Post-16 colleges may be in asimilar situation. As a result of the Further and Higher Education Act 1992 many of thesemay be funded by the Further Education Funding Council and may not be able to usethe Schools etc Exemption Order. As some colleges have significant holdings ofradioactive substances the other Exemption Orders may not cover the situation andhence registration may be necessary. If in doubt, members may contact the CLEAPSSHelpline for further advice.9.1.3 Limits set by government education departmentsIn the past, the government education departments have had an approval system forthe types of sources permitted to be used in schools and colleges. However, this hasbeen abolished for schools in England3. (Parallel legislation for institutions of furthereducation came into force in 20044. Discussions between the DCSF and the Learning &Skills Council should decide the future of that legislation.) The conditions set out in The

1 The Radioactive Substances (Schools etc.) Exemption Order 1963 [or the Radioactive Substances (Schools etc.)

Exemption Order (Northern Ireland) 1963]. This and other older legislation and guidance often refers toclosed sources rather than sealed sources. The definition of a sealed source in recent legislation meansthat all school sources in normal use can be described as sealed sources; see section 12.1 for a precisedefinition.

2 Or the Chief Inspector within the Environment and Heritage Service in Northern Ireland.3 Government regulation of the radioactive sources used in schools dates back at least to 1957 when the

Ministry of Education issued Administrative Memorandum AM547 (29th March 1957). However, in2005 the DfES reviewed its policy of approving radiation products for school use and those whosupplied or made them. The DfES concluded that, administrative memoranda being advisory, suchapproval was inappropriate and could be replaced by advice on product specification from thosewith suitable expertise. In 2006, the DfES approached CLEAPSS to convene a group to draw up aspecification (ie, a standard) and establish a consensus amongst the science education andradiological protection communities about its suitability. Use of this would not be mandatory but itwas generally expected that radiation employers would adopt it and in future require schools topurchase only sources complying with it. This is available on request from CLEAPSS as guide L256,Specification of Radioactive Sources for School Use. Note, however, that this is a technical document, notreally intended for schools, just for manufacturers, suppliers and employers.

4 The original legislation placed the power of approval with the Secretary of State in the Departmentfor Education and Skills for which the relevant successor body is the Department for Innovation,Universities and Skills (DIUS) but health and safety has been delegated to the Learning and SkillsCouncil (LSC). However, at the time of writing, the power does not appear to have been used byDIUS or LSC.

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Radioactive Substances (Schools, etc) Exemption Order 19631, and other Exemption Orders,remain in force.If a new approval letter is required in Wales or Northern Ireland or for colleges inEngland it should be requested from the appropriate office listed below. In Wales, aform2 will need to be completed and returned. The form requests details of:

the education establishment; any previous approvals; the RPA; the RPS; the radioactive sources already kept; the radioactive sources to be purchased.

Following the application, an approval letter should arrive within a few weeks.

Application for approval to work with ionising radiations should be made to:

School Revenue & Funding and Health & SafetySchools Management Division 4National Assembly for Wales, Cathays Park, Cardiff CF10 3NQ

For maintained schools in Wales

Tel:E-mail:Web site:

029 2082 6066david.slade@wales.gsi.gov.ukwww.wales.gov.uk

Building BranchDepartment of Education Northern Ireland (DENI)Rathgael House, Balloo Road, Bangor, Co. Down BT19 7PR

For maintained schools inNorthern Ireland

Tel:Fax:E-mail:Web site:

028 9127 9279028 9127 9100deni@nics.gov.ukwww.deni.gov.uk

The Learning and Skills Council,Cheyesmore House,Quinton Road,CoventryCV1 2WT

For post-16 colleges in England

Tel:Fax:E-mail:Web site:

0845 019 4170024 7682 3675info@lsc.gov.ukwww.lsc.gov.uk

9.2 Buying radioactive sources

9.2.1 Suitable sourcesRadioactive sources, including unsealed sources, should be obtained from educationalsuppliers. With the publication of the CLEAPSS guide L256, Specification of RadioactiveSources for School Use new sources may come on the market and there may be newsuppliers. Members should consult CLEAPSS for a current list of suppliers3 whosesources are believed to meet the specification.Very occasionally, CLEAPSS has heard of sources on sale, from an educationalsupplier, that were not formally approved for use by schools in the past and may not

1 Or the Radioactive Substances (Schools, etc) Exemption Order (Northern Ireland) 1963.2 Form IR(C) for schools applying for category C approval.3 See the latest version of the CLEAPSS leaflet PS78 Radioactive Sources for School Use. This is likely to

change over time and the latest version will be on the members’ part of the CLEAPSS web site.

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meet the requirements of the Specification of Radioactive Sources for School Use. Inaddition, schools are sometimes tempted to acquire radium-luminised equipment suchas altimeters or military compasses. These are not covered by the Exemption Ordersand are not suitable for school use. If there is any uncertainty about the suitability of asource, contact CLEAPSS or the RPA (via the RPO in local authorities subscribing to theCLEAPSS scheme) for advice.CLEAPSS knows of instances in which schools have acquired radioactive substances ofdubious origin, which have been very costly to dispose of. Existing stocks of unusualsources should be stored safely and not used. Contact CLEAPSS or the RPA (via theRPO in local authorities subscribing to the CLEAPSS scheme) for advice.

9.2.2 Placing an order for a radioactive sourceWhen placing an order for a radioactive source it may be necessary to confirm to thesupplier that the school or college is allowed to hold sources under the RadioactiveSubstances (Schools etc) Exemption Order (see section 9.1.2). In the past, maintainedschools would have been expected to send a copy of the letter of approval or a letter ofpermission to buy. Although this regime, linked to Regulation 7 of the Education(Schools and Further and Higher Education) Regulations 1989 no longer exists in Englandwe expect some teething problems as schools and suppliers adjust to de-regulation. Wehave provided a model letter to use in its place, see section 5.6. The DCSF will answerany queries put to them. In cases of difficulty, please contact CLEAPSS.When a new radioactive source is purchased, the RPS (Schools) should keep copies ofall relevant paperwork (eg, order, delivery note, invoice, instructions and safety datasheets). Schools have found these documents extremely useful, for example, whendisposal becomes necessary in the future.

10 Transportation of radioactive sourcesThe transportation by road of school radioactive sources is rarely necessary and shouldbe reduced to a minimum. If sources are often used in laboratories on different sites, itis far better to have a separate store and sources at each location. If necessary, underthese circumstances, the Standard School Holding may be exceeded for the school as awhole provided the Standard School Holding is maintained on each site.The transportation of all radioactive substances is covered by detailed legislation1.When packed correctly, following the procedures below, any source covered by theStandard School Holding becomes an ‘Excepted Package‘ under the Regulations.If there is any uncertainty about the transport of radioactive material, CLEAPSS shouldbe consulted for advice. In some circumstances, the RPA may also be willing to advise(via the RPO for local authorities subscribing to the CLEAPSS service). Radioactivematerials should never be transferred to other establishments without informing therelevant RPA(s) (via the RPOs where relevant).Radioactive material must not be carried on public transport.

1 The Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations 2007 [or The Carriage by

Road Regulations (Northern Ireland) 1984, due to be replaced shortly].

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10.1 Driver awareness trainingIf radioactive material must be transported, no special driver training is requiredbecause the effective dose is so low and the quantities so small. However, generaldriver awareness training is expected, including on what to do in the event of anaccident. This condition could be met if the driver of the vehicle is a member of thescience staff who is familiar with handling the sources. S/he could be given a briefingnote along the following lines.Before leaving, the driver must:• Check that a completed consignor’s certificate (transport document – see section

10.4) accompanies the package(s) and that the number of packages tallies with thecertificate;

• Check that the package(s) is in good condition for road transport;• Put the package(s) securely in the car, preferably in the boot if there is one and lock

the boot on departure;• Plan to take the most direct route;• Know that the vehicle is not to be left unattended without reasonable cause and that

it must be locked if unattended;• Have arrangements in place for back up transport in the event of a breakdown (eg,

membership of the AA, RAC or similar);• Know that, in the event of a breakdown or minor accident in which no one is

injured and the radioactive packages are undamaged, s/he should inform theconsignor that there will be a delay and if necessary implement the back-uparrangements;

• Know that, in the event of more serious incidents (eg, theft, loss or likely damage),the local police should be informed immediately, giving them details but taking careto avoid over-reaction ;

• Know that, in the event of more serious incidents, the driver should report theincident to the employer and make notes of the incident as soon as possible, as thiscould be useful in assessing exposure.

10.2 PackagingRegulations require the package to retain its contents under conditions likely to befound in routine transport. Also, the dose rate at any point on the external surface ofthe package must not exceed a specified limit (5 µSv/h). This could be achieved byshielding or by having the source at the centre of a relatively large container thusrelying on the inverse square law effect. If the guidance below is followed, theserequirements will be met.Strontium-90, plutonium-239 and americium-241 cup sources, in their normalcontainers, can be transported in any outer container.Radium-226 and almost new cobalt-60 sources will require action to bring the surfacedose rate below specified limits. This can be achieved by filling an ordinary plasticbucket with polystyrene foam with the source box at its centre. Alternatively, a largecardboard box can be used, packed with smaller boxes, such that the wooden sourcebox is at least 5 cm from the wall.A uranium or thorium compound (in an appropriate container) must be carried withinrobust containers, usually metal (eg, a tool box) such that damage is extremely unlikely inevent of a road accident.

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Transportation of radioactive material in solution should be restricted to a 30 cm3

protactinium generator. This should be kept upright and surrounded by a mineralabsorbent (cat litter) in a sturdy, water-tight outer container, wrapped in a strong plasticbag. This is tied and securely packed in robust containers, usually metal (eg, a tool box)such that damage is extremely unlikely in event of a road accident.All packages should be loaded securely, as far as possible from the occupants, and out ofsight, in the boot of the vehicle. The vehicle must be locked whenever it is left unattended.There should be a regular check of the packages used for transport of radioactive materialto confirm that they have not become contaminated. This could be achieved by keeping acopy of the consignor’s certificate (transport document or consignment note), see section10.3, with a record of any contamination records on the packaging. Records must be keptfor at least two years (and preferably much longer). In schools, it may be convenient to dothis when other monitoring tasks are carried out.Check that the driver’s car insurance is valid for transporting ‘excepted packages’. It mayhelp reassure insurers by explaining that the source activities are of the same order ofmagnitude as domestic smoke detectors.

10.3 LabellingNo external signs are required on the vehicle. Each item inside a package should be suitablylabelled. The package must have the marking ‘Radioactive’ on the internal surface in such away that a warning of radioactive material is visible on opening the package.The outside of an excepted package should show the UN number and the name of theconsignee. The UN number is 2910 for sealed sources, protactinium generators, uraniumand thorium compounds, cloud chamber sources or radioactive materials. The UN numberis 2911 for “instruments and articles”, eg, spinthariscopes, expansion cloud chambers withnon-detachable radioactive material, clocks or instruments with radioluminescent paint.Suitable labels are shown below.

In the event of an accident, contact the police andName:

School:

Telephone:

In the event of an accident, contact the police andName:

School:

Telephone:

Excepted package, UN Class: 7, UN Number: 2910

Limited quantity of radioactive material

The driver of this vehicle carries a consignor’s certificate.

Excepted package, UN Class: 7, UN Number: 2911

Limited quantity of radioactive material

The driver of this vehicle carries a consignor’s certificate.

10.4 DocumentationIf it is ever necessary to transport school radioactive sources by road, an appropriateconsignor’s certificate (transport document or consignment note) must be prepared. Acopy should be kept at the school and one must accompany the driver. It is prudent toput a further copy inside the package itself. Suitable documents are shown on the nextpage1, the choice of certificate (UN 2910 or UN 2911) depending on how the packagehas been labelled (see section 10.3).

1 An electronic version will be found in the Customisable Documents sections of both the CLEAPSS

Science Publications CD-ROM and the members’ part of the CLEAPSS web site.

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Consignor’s Certificate (Transport Document)The Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations 2007

Consignor

(Name & address of school sending the package)

Consignee

(Name & address of school receiving the package)

Contact phone number Contact phone number

Contact name [RPS (Schools) etc] Contact name [RPS (Schools) etc]

Shipping name RADIOACTIVE MATERIAL,EXCEPTED PACKAGE

LIMITED QUANTITY OF MATERIAL

United Nations Number UN 2910

Package number

Nuclide(s) (name(s) of radioactive material)

Physical / chemical form (solid or liquid) / sealed, etc

Activity / quantity

DECLARATION

I hereby declare that the contents of this consignment are fully and accurately described above by proper shipping name andare classified, packaged, marked and labelled, and are in all respects in proper condition for transport by road according to theapplicable international and national governmental regulations.

Signed by [RPS (schools)]

Date of commencement of journey

Vehicle registration number

Name and signature of driver

This vehicle is carrying

small amounts of

RADIOACTIVE MATERIAL.

In case of accident, get in touch with

THE POLICE

and School, Tel. No.

© CLEAPSS 2008

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Consignor’s Certificate (Transport Document)The Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations 2007

Consignor

(Name & address of school sending the package)

Consignee

(Name & address of school receiving the package)

Contact phone number Contact phone number

Contact name [RPS (Schools)etc] Contact name [RPS (Schools)etc]

Shipping name RADIOACTIVE MATERIAL,EXCEPTED PACKAGE

LIMITED QUANTITY OF MATERIAL

United Nations Number UN 2911

Instruments and articles

DECLARATION

I hereby declare that the contents of this consignment are fully and accurately described above by proper shipping name andare classified, packaged, marked and labelled, and are in all respects in proper condition for transport by road according to theapplicable international and national governmental regulations.

Signed by [RPS (schools)]

Date of commencement of journey

Vehicle registration number

Name and signature of driver

This vehicle is carrying

small amounts of

RADIOACTIVE MATERIAL.

In case of accident, get in touch with

THE POLICE

and School, Tel. No.

© CLEAPSS 2008

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11 Disposal of radioactive sources

11.1 Reasons not to dispose of radioactive sourcesCLEAPSS receives regular Helpline enquiries from schools wishing to dispose ofradioactive sources. Many unacceptable reasons are given for disposal of radioactivesources. Our responses, and references to sections of this guide, are given below.

We have no satisfactory location to store the sources.The minimum storage requirement is normally easy to achieve (section 3.6.2). Ifthere are difficulties, consult CLEAPSS or the RPA (via the RPO in localauthorities subscribing to the CLEAPSS scheme).

We have security problems and are not happy to store sources at our school.If there are security problems, there are plenty of other items in the sciencedepartment which pose risks that are the same as, or greater than, the theft ofradioactive sources. The security problems need to be addressed.

None of our teachers know what to do with the sources.All qualified science teachers who teach about radioactivity should be confidentin handling radioactive sources and carrying out basic demonstrations. Appro-priate training should be given (section 2.4.3).

We don't think radioactive sources are safe to use and prefer to describe the demonstra-tions, show videos of them or use a computer simulation.The standard educational radioactive sources are very safe when handled andused according to the guidance from CLEAPSS and, where appropriate, the gov-ernment education department. Pictures, videos and computer simulations maycomplement, but are no substitute for, practical work in science.

We don't teach about radioactivity any more.Radioactivity is included in the various national curricula and is an importantpart of advanced level work in science (section 1.6).

We can detect radiation from a source outside its container.This is perfectly normal for sources that emit gamma radiation (eg, cobalt-60 andradium-226). Gamma radiation is the most penetrating and will pass through allsubstances including lead. A raised count rate around the container is normal.

The radium source is contaminating its pot.Radium sources emit small amounts of radon gas which can deposit radioactivedecay products in the lead container. This is quite normal and is dealt with byroutine decontamination (section 4.2.3).

The sources are not working and need to be replaced.Our most usual finding, when schools report a non-emitting source, is that themeasuring equipment is faulty or being used incorrectly. Some authorities havesuggested that school sealed sources have a useful life of only 5 to 10 years.However, all the evidence available to staff at CLEAPSS indicates that well-cared-for sources will last for decades. Provided a source has passed its annualleak test, there is no reason to dispose of it. Even a source that has completedseveral half lives (eg, cobalt-60) can often be put to good use to demonstratedating techniques.

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We have a few grams of uranyl nitrate that we never use.Use 1.5 g of uranyl nitrate to make a protactinium generator (instructions onCLEAPSS Recipe Card 57). Maintained schools may keep up to 100 g of uraniumcompounds in the radioactive sources store. If disposal is still necessary, nearbyschools may be interested as supplies are often difficult to obtain.

We do not have any detection equipment to carry out investigations.A GM tube and scaler are required to check for leakage and contamination ifradioactive substances are stored (whether they are used or not). New detectionequipment can be bought with the money saved by not disposing of the sourcesor existing equipment can be repaired. Occasionally, appropriate equipment islurking at the back of a cupboard.

Many science departments already have datalogging equipment for which aradiation probe can be purchased. Money from an ICT budget might be used forthis purpose. Note, however, that some of the probes supplied with dataloggingequipment may not be suitable for leak testing and contamination checks.

In an emergency, it may be possible to borrow detection equipment from anotherschool or college.

11.2 Reasons to dispose of radioactive sourcesThe following are usually valid reasons for disposing of radioactive sources.

A school is exceeding the Standard School Holding, often as a result of schoolamalgamations, and has more sources than it uses.

A source is not suitable for use in schools (eg, old military instruments withradium dials).

A source has been damaged or is leaking (extremely rare).

A source has become too weak (only applies to those with shorter half lives, eg,cobalt-60 and, very occasionally, strontium-90 sealed sources).

11.3 Methods of disposal

11.3.1 Very low-level radioactive waste (VLLW)After use, all solid waste such as tissues, paper towels, plastic gloves, dust masks,bench coverings, empty bottles etc that may be contaminated by small amounts ofradioactive substances1 should be double-bagged by placing it in strong plastic bags,which are tied for disposal in the refuse. Waste of this type should not be labelledbecause it could cause unnecessary concern. It is best if the bag is placed directly into amain waste bin (outside the building), shortly before it will be emptied by a refusecontractor. This reduces the possibility of theft or accidental contamination of otherpeople and is good practice even if the risk is vanishingly small.

1 Less than 40 kBq for each item, or 400 kBq in total in 0.1 m3, up to a maximum of 400 kBq per week.

See Policy for the Long Term Management of Solid Low Level Radioactive Waste in the United Kingdom,available at www.defra.gov.uk/environment/radioactivity/waste/pdf/llw-policystatement070326.pdf.

75

11.3.2 Disposal of surplus radioactive sourcesA decayed cobalt-60 or strontium-90 source can be kept and compared with a new oneto demonstrate decay over time, leading to discussions on dating techniques. Exceedingthe Standard School Holding in this context is regarded as acceptable1 (see section 3.2).Sources in good condition may be transferred to other schools (provided the RPA(s)involved are in agreement and the Standard School Holding is not exceeded).In 2006, the Environment Agency (in England and Wales) issued guidance on thedisposal of some radioactive sources from schools via the sewage system or via therefuse collection2. See below for detailed instructions and see section 11.5 forapplicability. In some cases, there are restrictions on the amount which can be disposedper day or per week; where applicable, this is shown in the table in section 11.5.Where there is a damaged source, it may be possible to encapsulate it, eg, in epoxyresin, and then dispose of it as a sealed source.Otherwise, sources will need to be removed from the school via an authorisedcontractor, which will be very expensive. Advice should be sought from CLEAPSS orthe RPA (via the RPO for local authorities subscribing to the CLEAPSS service).Organisations offering a disposal service for radioactive sources are listed in 11.4.Always ensure that a detailed receipt is provided by anyone who collects radioactivesubstances. This should include details of each source, its activity and the name andaddress of the organisation accepting responsibility for it. Keep the receipt with thesource histories.When disposing of sources, a risk assessment is required. This is generally covered bythe Model Risk Assessments in section 7, but some customisation may be necessary todeal with particular circumstances.

11.3.3 Disposal of uranium and thorium compoundsIn England and Wales3, schools are permitted to dispose of up to 100 g per day ofuranium or thorium compounds4 (in the refuse or via the sewage system), but it isnormal to keep well below this limit. There are differences of opinion between expertsas to which method is most appropriate.Via a foul-water drain, the radioactive substance is widely dispersed and virtuallyundetectable once diluted many thousands of times. On the other hand, preparation forfoul-water drain disposal can expose staff to additional hazards if (for example) aradon-220 generator needs to be dismantled and the contents dissolved.Preparation for solid disposal is generally less hazardous for staff. On the other hand, ina landfill site, the radioactive substance remains concentrated and could leak out atsome time in the future. 1 The Standard School Holding limits are based on the original activity stated on the source or its

container.2 In Northern Ireland, all sealed radioactive sources must be disposed of only via transfer to another

school or to a person authorised under the Radioactive Substances Act 1993 to accept and dispose ofsuch radioactive waste.

3 In Northern Ireland, the NI Regional Medical Physics Agency offers a disposal service for uraniumand thorium compounds (at a cost).

4 Under the Radioactive Substances (Prepared Uranium and Thorium Compounds) Exemption Order 1962 [orthe Radioactive Substances (Prepared Uranium and Thorium Compounds) Exemption Order (NorthernIreland) 1962].

76

On balance, the CLEAPSS-preferred method, particularly for a few grams of readilysoluble compounds (and certainly if the compound is already in solution) is as a solu-tion poured down a ‘foul-water drain’, ie, a toilet connected to a main sewer. Where asolid uranium or thorium compound is sealed within a container that is either difficultto open or, when opened, would present a hazard which might be difficult to control,solid waste disposal should be considered, especially if the compound would bedifficult to dissolve (eg, oxides).

Disposal of surplus radioactive sources as solid waste in the refuse collection

See Section 11.5 for the applicability of this method. The source is immobilised in aslurry of cement mortar or plaster of Paris so that it is completely surrounded byseveral centimetres of material on all sides. (Immobilisation is not needed for rocksamples, smoke detectors or gas mantles – these can be placed directly in the refuse.) Itis then placed in the refuse collection. This method must not be used for liquid waste. Wastedisposed of via the solid refuse should not be labelled because it could causeunnecessary concern.

Before taking action, inform the RPA (via the RPO for local authoritiessubscribing to the CLEAPSS scheme).

The waste disposal company does not need to be informed (but check the table insection 11.5 regarding eligibility).

Choose a quiet time when interruptions are unlikely. Wear a lab coat and disposable gloves. Also wear a disposable dust mask, CE

marked, FFP3 rated when handling unsealed powders such as thoriumcompounds but this is not necessary if the bottle or container is not opened.

Work in a draught-free environment and over a tray to contain any spills. If it is a uranium or thorium compound, remove all warning and identification labels

from the bottle or other container. Wrap the compound, in its container, in twostrong plastic bags which are then sealed with tape, making a tidy package withno protrusions.

If it is a sealed source place the source in a small, unlabelled, rugged container, eg aplastic screw top bottle or jar.

Prepare a stiff mortar slurry using a ready-mixed mortar or about 1 part ofcement with 4 parts of sand, adding only a limited quantity of water or useplaster of Paris. (As necessary, wear gloves and eye protection.)

Half fill an unlabelled, large container, such as an empty 2.5 litre catering tin,with the slurry.

Insert the wrapped package or rugged container into the slurry so that it ispositioned in the middle of the large container.

Fill the rest of the space in the large container with more of the slurry so that thepackage is completely encased and put the lid on the container.

Leave the large container in a locked, secure cupboard for about a week, until theslurry has set.

Shortly before the collection is due, place the unlabelled, large container directlyinto a main refuse container (outside the building), which will be emptied by arefuse contractor.

77

Disposal of surplus radioactive sources via the sewage system

This is only applicable to uranium and thorium compounds1, see section 11.5. A solution ofthe compound is flushed away down a toilet connected to a main sewer (not a septic tank!).More information is provided on CLEAPSS Hazcards 101 and 105.

Before taking action, inform the RPA (via the RPO for local authorities subscribing tothe CLEAPSS scheme).

The sewerage undertaker (water company) does not need to be informed. Choose a quiet time when interruptions are unlikely and corridors are clear. Wear a lab coat and disposable gloves (also a disposable dust mask, CE-marked FFP3

rated, when handling unsealed powders, such as thorium compounds and goggles ifdealing with corrosives, such as acid solutions).

Work in a draught-free environment and in a tray to contain any spills. Uranyl compounds and thorium nitrate should be dissolved in water. Other uranium

and thorium compounds would need 2 mol dm-3 nitric acid (see CLEAPSS Hazcard67) and in that case disposal via the refuse might be preferred. A conical flask, with astopper for later use, is usually suitable for this process. Always test solubility withvery small quantities first. In some circumstances, dissolving can take some time. Ina few cases, it may be necessary to use mechanical stirring and possibly add a littleconcentrated nitric acid.

Carry the resulting solution, in the stoppered flask or other closed container, (restingin an empty plastic bucket) to a toilet.

Gently tip the solution into half a bucket of water. Pour the solution from the bucket down the centre of the toilet and flush at least

twice, to ensure that the radioactive substance does not collect in traps etc. Thoroughly wash out all containers in a sink with a fast-flowing waste outlet. After use, fill the sink and empty it at least once to ensure that any radioactive

substance does not collect in traps etc.

11.4 Organisations offering a disposal serviceDisposal of sealed radioactive sources by a contractor can be expensive and time-consuming. Where possible, disposal by approved DIY methods (see section 11.3) ispreferred and encouraged. In some cases, alternatives to disposal are more straightforward;see section 11.1. Options should be discussed with CLEAPSS and/or the RPA before anydisposal arrangements are made.Where other routes are not available the organisations listed below will require specialforms to be completed before finalising prices (if appropriate) and arranging collection.Whenever a radioactive substance is removed from an establishment, a detailed receipt,giving full details of the collection, should be filed with the history of the sources.

1 The Schools Exemption Order also allows up to 18.5 MBq of liquid down the drains per week, but this

must not include alpha-emitters or strontium-90.

78

Company Address CommentsActive CollectionBureau Ltd

Noble House,Brickmakers,Castle Road,Sittingbourne, Kent,ME10 3RLTel: 01795 437001Fax: 01795 599800

GE Healthcare Amersham LaboratoriesWhite Lion RoadAmershamHP7 9LLTel: 01494 544000Fax: 01494 543588

The company will only disposeof radioactive sources originallyproduced by NycomedAmersham.These include all Philip Harrisand Griffin & George sealed cupsources.

Northern IrelandRegional MedicalPhysics Agency

Northern Ireland Regional MedicalPhysics AgencyForster Green Hospital110 Saintfield RoadBelfastBT8 4HDTel: 028 9094 4385Fax: 028 9070 3819

For schools in Northern Irelandonly. The Service will arrange fordisposal of any radioactivesource including uranium andthorium compounds.Prior agreement must beobtained from DENI.

At the time of writing (August2008) the future of this service isnot entirely clear.

Energy Solutions

(previously SafeguardInternational Ltd)

B168 Maxwell AvenueHarwell Business CentreDidcotOX11 OQTTel: 0800 328 3790Fax: 01235 822580

E-mail:enquiries@energysolutions.uk.com

Web site: www.energysolutions.uk.com

79

11.5

Sum

mar

y of

pos

sibl

e di

spos

al m

etho

dsDi

spos

alop

tions

Sour

ce

Give

toan

othe

rsc

hool

Disp

ose

via se

wer

Disp

ose

via re

fuse

Colle

cted

by

auth

orise

dco

ntra

ctor

Com

men

tsDi

spos

al via

the

sewe

r or r

efus

e is

not c

urre

ntly

perm

itted

in No

rther

n Ire

land

Seale

d sou

rces

(cup t

ype o

rPe

rspex

slide

sor

from

expa

nsion

cloud

cham

ber),

Ra-

226,

Co-6

0, Sr

-90

/Y-9

0, Am

-24

1, Th

-232

,Pu

-239

(a)

(b)

(c)

Smok

e alar

mco

ntaini

ng no

more

than

40kB

q (1µ

Ci) A

m-24

1

(a)

(d)

(c)

Gas m

antle

sim

preg

nated

with

thoriu

mco

mpou

nds

(a)

(e)

(c)

Natur

al ro

cksa

mples

(a)

(f)

(c)

(a) T

rans

fer to

anoth

er sc

hool

only

with

the p

rior a

gree

ment

of the

rece

iving

RPA

; e

nsur

e Sta

ndar

d Sc

hool

Holdi

ng at

the r

eceiv

ing sc

hool

is no

t exc

eede

d.(b

) For

refus

e disp

osal,

no s

ource

to be

mor

e tha

n 200

kBq (

5 µCi

) and

no m

ore t

han o

ne so

urce

per w

eek;

sou

rce to

be gr

outed

into

rugg

ed co

ntaine

r;re

fuse

to be

coll

ected

by

your

loca

l auth

ority

’s int

erna

l was

te co

ntrac

tor o

r by

exter

nal c

ontra

ctor w

ho o

pera

tes o

nco

ntrac

t to yo

ur lo

cal a

uthor

ity ev

en if

there

is a

sepa

rate

contr

act fo

r you

r sch

ool.

NOT

avail

able

in N

orth

ern

Irelan

d.(c)

Coll

ectio

n by a

n auth

orise

d con

tracto

r is a

very

expe

nsive

optio

n – ot

her r

outes

shou

ld be

cons

idere

d firs

t.(d

) For

refus

e disp

osal,

not

more

than

1 sm

oke d

etecto

r in an

y 0.1

m3 of n

orma

l refus

e and

the r

efuse

to be

disp

osed

as so

on as

prac

ticab

le;re

fuse

to be

coll

ected

by

your

loca

l auth

ority

’s int

erna

l was

te co

ntrac

tor o

r by

exter

nal c

ontra

ctor w

ho o

pera

tes o

nco

ntrac

t to yo

ur lo

cal a

uthor

ity ev

en if

there

is a

sepa

rate

contr

act fo

r you

r sch

ool.

sou

rce do

es no

t nee

d to b

e gro

uted i

nto ru

gged

conta

iner –

can g

o dire

ctly i

nto re

fuse.

(e)

Disp

osal

via th

e refu

se co

llecti

onre

fuse

to be

coll

ected

by

your

loca

l auth

ority

’s int

erna

l was

te co

ntrac

tor o

r by

exter

nal c

ontra

ctor w

ho o

pera

tes o

nco

ntrac

t to

your

loca

l auth

ority

eve

n if

there

is a

sep

arate

con

tract

for y

our s

choo

l, or

, if i

t is

a no

n-loc

al au

thority

contr

actor

the r

efuse

goes

to la

ndfill

; s

ource

does

not n

eed t

o be g

route

d into

rugg

ed co

ntaine

r – ca

n go d

irectl

y into

refus

e.(f)

Di

spos

al via

the r

efuse

colle

ction

must

not e

xcee

d 10

0 g

of ur

anium

and

thor

ium p

er d

ay (b

ut 50

0g o

f roc

k will

conta

in mu

ch le

ss th

an 1

00g

of ur

anium

or th

orium

);re

fuse

to be

coll

ected

by

your

loca

l auth

ority

’s int

erna

l was

te co

ntrac

tor o

r by

exter

nal c

ontra

ctor w

ho o

pera

tes o

nco

ntrac

t to

your

loca

l auth

ority

eve

n if

there

is a

sep

arate

con

tract

for y

our s

choo

l, or

, if i

t is

a no

n-loc

al au

thority

contr

actor

the r

efuse

goes

to la

ndfill

; s

ource

does

not n

eed t

o be g

route

d into

rugg

ed co

ntaine

r – ca

n go d

irectl

y into

refus

e.

80

Disp

osal

optio

nsSo

urce

Give

toan

othe

rsc

hool

Disp

ose

via se

wer

Disp

ose

via re

fuse

Colle

cted

by

auth

orise

dco

ntra

ctor

Com

men

tsDi

spos

al via

the

sewe

r or r

efus

e m

ay n

ot b

e av

ailab

le in

North

ern

Irelan

d

Uran

ium an

dtho

rium

comp

ound

s? (

g) (h

) (i)

(c)

Lumi

nous

clock

s or

watch

eslum

inise

d with

Ra-2

26

(a)

(j) (c

)

Dama

ged o

run

know

nso

urce

s or

sour

ces

unsu

itable

for

scho

ol us

e

(k)

(g) D

ispos

al to

other

scho

ols c

ould

includ

e ura

nyl n

itrate

to all

ow th

em to

mak

e pro

tactin

ium ge

nera

tors;

cou

ld inc

lude c

omple

te pr

otacti

nium

or ra

don-

220 g

ener

ators

in go

od co

nditio

n; s

hould

NOT

inclu

de th

orium

comp

ound

s as t

his w

ould

be ou

tside

the S

tand

ard

Scho

ol Ho

lding

.(h

) Disp

osal

via se

wer

only

if the

foul

drain

age g

oes t

o the

publi

c sew

er, n

ot a s

eptic

tank

; m

ust n

ot ex

ceed

100 g

of ur

anium

and t

horiu

m co

mpou

nds p

er da

y (inc

luding

any d

ispos

ed vi

a refu

se);

sho

uld be

used

for s

olutio

ns;

is t

he be

st op

tion f

or co

mpou

nds e

asily

solub

le in

water

(ura

nyl c

ompo

unds

); i

s wor

th co

nside

ring f

or co

mpou

nds t

hat e

asily

diss

olve i

n dilu

te nit

ric ac

id (ca

rbon

ates).

(i) D

ispos

al via

refus

e coll

ectio

n m

ust n

ot ex

ceed

100 g

of ur

anium

and t

horiu

m co

mpou

nds p

er da

y (inc

luding

any d

ispos

ed vi

a sew

er);

is n

ot su

itable

for s

olutio

ns;

sou

rce to

be gr

outed

into

rugg

ed co

ntaine

r; i

s the

best

optio

n for

comp

lete r

adon

-220

gene

rator

s; i

s the

best

optio

n for

comp

ound

s tha

t do n

ot dis

solve

easil

y in d

ilute

nitric

acid

(oxid

es, h

ydro

xides

);re

fuse

to be

coll

ected

by

your

loca

l auth

ority

’s int

erna

l was

te co

ntrac

tor o

r by

exter

nal c

ontra

ctor w

ho o

pera

tes o

nco

ntrac

t to

your

loca

l auth

ority

eve

n if

there

is a

sep

arate

con

tract

for y

our s

choo

l, or

, if i

t is

a no

n-loc

al au

thority

contr

actor

the r

efuse

goes

to la

ndfill

.(j)

Fo

r disp

osal

via th

e nor

mal re

fuse c

ollec

tion,

EITH

ER T

he di

al ca

rries

the m

anufa

cture

r’s m

ark “

Ra 1.

5” an

d the

re is

no m

ore t

han 5

60 kB

q (15

µCi

) of R

a-22

6, OR

The

cloc

k dial

is un

marke

d and

ther

e is n

o mor

e tha

n 7.4

kBq (

0.2 µ

Ci) o

f Ra-

226,

OR T

he w

atch d

ial is

unma

rked a

nd th

ere i

s no m

ore t

han 5

.6 kB

q (0.1

5 µCi

) of R

a-22

6.(k)

This

meth

od h

as to

be

used

whe

re th

e na

ture

of the

sou

rces

or th

e loc

al wa

ste d

ispos

al or

sew

age

arra

ngem

ents

make

other

route

s imp

racti

cal.

81

12 Definitions and doses

12.1 Definitions

Radionuclide

A radionuclide is an atom with an unstable nucleus which undergoes radioactivedecay, emitting ionising radiation.

Ionising radiation

The transfer of energy in the form of particles or electromagnetic waves of a wave-length of 100 nanometres or less or a frequency of 3 x 1015 hertz or more, capable ofproducing ions directly or indirectly1.

Radioactive substance

Any substance which contains one or more radionuclides whose activity cannot bedisregarded for the purposes of radiation protection1.

Sealed source

A source containing any radioactive substance whose structure is such as to prevent,under normal conditions of use, any dispersion of radioactive substances into theenvironment1. The term ‘Closed source’ was used in older legislation.

Unsealed source

Radioactive material that could be dispersed in normal use, hence causingcontamination. The term ‘Open source’ is used in older legislation and remains inoccasional use. An unsealed source used as a chemical is also called a radiochemical.

Activity

The activity of a radioactive substance is measured in becquerels. A substance in whichone atom disintegrates (or transforms) per second is said to have an activity of onebecquerel (1 Bq). This is a very low activity. For example, the Health Protection Agency(previously National Radiological Protection Board) reports that the average radonlevel in UK homes is 20 Bq per cubic metre of air2.The curie (Ci), based on the activity of 1 g of radium, was a very large activity (equiv-alent to 3.7 x 1010 Bq). Since older radioactive sources are often labelled in Ci, theconversion table below may be of assistance (activities listed are typical for schoolsealed sources). Note that some conversions are approximate.

Old units of radioactivity / µCi ( x 37 = ) SI units of radioactivity / kBq

0.1 3.7

0.125 4.6

5.0 185.0

9.0 333.0

1 Most of these definitions appear in the Ionising Radiations Regulations 1999 [and the Ionising Radiations

Regulations (Northern Ireland) 2000].2 NRPB book Living with Radiation, (Fifth edition, 1998), ISBN 0 85951 419 6.

82

Half life

The half life of a radionuclide is the time taken for the activity to drop to half its initiallevel and it is measured in units, from fractions of a second to multiples of a year.

Radiation energy

The energies of the particles or photons emitted by radioactive substances are usuallyquoted in electronvolts (eV). One electronvolt is the increase in energy acquired by anelectron which has been accelerated by a potential difference of one volt, ie an increasein energy of 1.6 x 10-19 J.

Specific activity

The specific activity of a substance is the radioactivity per unit mass, usually expressedin becquerels per gram. The specific activity of a pure substance can be calculated, butno radioactive substance remains pure, since decay products (which are often radio-active too) will be formed, making the situation complicated. However, reasonableestimates can be made if the approximate date of manufacture is known. The tablegives data for the radioactive substances commonly used in schools and colleges.

Radioactive substance Initial specific activity Use

Uranyl(VI) nitrate-6-water 5.8 kBq g-1 for U-238

Manufactured from depleteduranium, which is mainly U-238 butowing to decay products and tracesof U-235 the actual activity isalways greater. Some months aftermanufacture it could rise to a totalof 24 kBq g-1

Protactinium generator

Thorium hydroxide 3.14 kBq g-1 for Th-232

but owing to decay products oldsamples could rise to a total of30 kBq g-1

Radon-220 (thoron)generator

Thorium minerals 0.18 kBq g-1 Active rock samples

Uranium minerals 5.00 kBq g-1 Active rock samples

12.2 DoseRadiation dose measurements and calculations are sophisticated and only a simplifiedexplanation is given here to provide a basic understanding.

Absorbed dose

The absorbed dose is the quantity of energy given by ionising radiation to a unit mass ofmatter (such as living tissue) and is measured in gray (Gy). One gray is the amount ofenergy which delivers one joule to a kilogram of absorbing material.

Equivalent dose

Different ionising radiations have different biological effects and this is taken intoaccount by multiplying the absorbed dose by a radiation-weighting factor.

83

Radiation type Radiation-weighting factor

Photons (X and γ) 1

β 1

Neutrons of various energies 5 to 20

α 20

This leads to a term known as equivalent dose measured in sievert (Sv), where,

Equivalent dose = radiation-weighting factor x absorbed dose

Some parts of the human body are more sensitive to radiation than others, so the equiv-alent dose is multiplied by a tissue-weighting factor, dependent on the organ exposed.The tissue-weighting factor varies from 0.01 (skin and bones) to 0.20 (gonads) and has awhole body total of 1. This leads to another term known as weighted equivalent dose,again measured in sievert (Sv), where,

Weighted equivalent dose = tissue-weighting factor x equivalent dose

Effective dose

The general term ‘dose’ (as used in this guide) usually means ‘effective dose’, which isthe sum of the weighted equivalent doses for the whole body. Effective dose gives abroad indication of detriment to health from any exposure to ionising radiation. Calcul-ations of effective dose are usually made using a sensitive dose meter and modellingthe dose to individual tissues by means of empirical formulae.

12.3 Dose from storage of school sourcesSchools sometimes raise concerns about radiation from sources in storage. HSEguidance1 advises that the dose rate outside of the store should not normally exceed2.5 microsieverts hour-1. Provided sources listed in the Standard School Holding arestored in accordance with the guidance in section 3.6, this figure should be achieved.

12.4 Dose from background compared to a school radioactive sourceIn the UK, the annual whole-body dose from background radiation is usually between1 and 10 mSv and, on average, about 2.7 mSv per person2. The dose received by the hand(not the whole body, the majority of which is further from the source) during a stand-ard school demonstration will be no more than 0.01 mSv. Consequently a teacher couldcarry out several hundred demonstrations in a year before acquiring an additional doseequal to background level. Doses to students observing demonstrations will be farlower. The legal maximum annual dose3 for an employee over the age of 18 is 6 mSv(except for those designated as classified workers, where the limit is 20 mSv) and for anemployee under the age of 18 or a member of the public it is 1 mSv.

1 Work with Ionising Radiation. Approved Code of Practice and Guidance, HSE, 2000. ISBN 0 7176 1746 7,

para. 505(c).2 Ionising Radiation Exposure of the UK Population: 2005 Review, HPA, 2005, ISBN 0-85951-558-3,

available at www.hpa.org.uk/radiation/publications/hpa_rpd_reports/2005/hpa_rpd_001.htm.3 Work with Ionising Radiation. Approved Code of Practice and Guidance, HSE, 2000. ISBN 0 7176 1746 7,

Regulation 8.

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The chart below includes data from the Health Protection Agency (previously, theNational Radiological Protection Board)1. It gives an indication of the radiation dosesreceived from various sources in the United Kingdom. In general, the largest personaldose is from radon gas. For comparative purposes, we have shown the dose receivedfrom 10 typical school demonstrations.

1 NRPB leaflet: Radiation Doses – Maps and Magnitudes (2nd edition, 1994). This information is now

available on the HPA web site www.hpa.org.uk.

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85

13 Legislation, codes of practice and guidanceThe legislation, codes of practice and guidance listed below are current at the time ofwriting (August 2008). It is unnecessary for schools to obtain all these documents.However, the RPS (Schools) may wish to be aware of the references on which ourguidance is based.

Legislation/code of practice/guidance Application to managing ionising radiationsand radioactive substances in schools andcolleges

The Ionising Radiations Regulations 1999

[or the Ionising Radiations Regulations (NorthernIreland) 2000]

Designed to implement EU legislation to ensurethat people working with ionising radiations areexposed to doses which are as low as reasonablypracticable.

Working With Ionising Radiation(HSE Books; 2000), ISBN 0 71761 746 7

Includes the Ionising Radiations Regulations1999, an Approved Code of Practice, which givesadvice on how to comply with the law andGuidance, which illustrates good practice.Available from:HSE Books, PO Box 1999, Sudbury, SuffolkCO10 2WA Tel: 01787 881165; Fax: 01787313995

The Radioactive Substances Act 1993 Controls the keeping, use and disposal ofradioactive substances. All users must registerwith the Competent Authority (the EnvironmentAgency in England and Wales, the ChiefInspector of the Heritage and EnvironmentService in Northern Ireland) unless exempt (seebelow).

The Radioactive Substances (Uranium andThorium) Exemption Order 1962

[or the Radioactive Substances (Uranium andThorium) Exemption Order (Northern Ireland)1962]

Conditionally exempts products containingquantities of thorium or uranium from some of therequirements of the Radioactive Substances Act.

The Radioactive Substances (Prepared Uraniumand Thorium compounds) Exemption Order 1962

[or the Radioactive Substances (PreparedUranium and Thorium compounds) ExemptionOrder (Northern Ireland) 1962]

Conditionally exempts these purified radioactivesubstances from some of the requirements of theRadioactive Substances Act, eg, regardingdisposal.

The Radioactive Substances (Schools etc)Exemption Order 1963

[or the Radioactive Substances (Schools etc)Exemption Order (Northern Ireland) 1963]

Conditionally exempts schools from registrationunder the Radioactive Substances Act undercertain conditions (eg, only certain, strictly-specified types of radioactive materials arepermitted for laboratory use).

The Radioactive Substances (GeologicalSpecimens) Exemption Order 1962

[or the Radioactive Substances (GeologicalSpecimens) Exemption Order (Northern Ireland)1962]

Conditionally exempts naturally occurringradioactive rocks from some of the requirementsof the Radioactive Substances Act.

The Radioactive Substances (TestingInstruments) (England & Wales) Exemption Order2006

[or the Radioactive Substances (TestingInstruments) (Northern Ireland) Exemption Order1986]

Conditionally exempts some instrument sourcesfrom some of the requirements of the RadioactiveSubstances Act, eg, regarding disposal.

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Legislation/code of practice/guidance Application to managing ionising radiationsand radioactive substances in schools andcolleges

The Radioactive Substances (Smoke Detectors)Exemption Order 1980, amended 1991

[or the Radioactive Substances (SmokeDetectors) Exemption Order (Northern Ireland)1980]

Conditionally exempts this equipment from someof the requirements of the RadioactiveSubstances Act, eg, regarding disposal.

The Radioactive Substances (Clocks andWatches (England and Wales) Regulations 2001

[or the Radioactive Substances (Basic SafetyStandards) Regulations (Northern Ireland) 2003]

Amends the Radioactive Substances Act 1993regarding the exemption on disposal of radio-luminised watches and clocks.

The Use of Ionising Radiations in EducationEstablishments (in Northern Ireland), DENI, 1986

Applies to education establishments in NorthernIreland. Interprets legislation and makes extrarules.Available from:Building Branch, Department of EducationNorthern Ireland, Rathgael House, Balloo Road,Bangor BT19 7PRTel: 028 9127 9279; Fax: 028 9127 9100.

The Education (Schools and Further and HigherEducation) Regulations 1989(England and Wales)

Gave governments the power to control work withradioactive substances in schools (and originallyin colleges) in England and Wales. However,Regulation 7 is repealed as far as England isconcerned as from September 2008 but currentlystill in force in Wales.

The Use of Ionising Radiations in EducationEstablishments in England & WalesAdministrative Memorandum 1/92,DES and Welsh Office, 1992

Withdrawn as far as England is concerned asfrom September 2008.

The Education (Special Educational Needs)(Approval of Independent Schools) Regulations1994

Gave governments the power to control work withradioactive substances in independent specialschools but Paragraph 7 of Schedule I wasrepealed as from September 2008.

The Education (Hazardous Equipment andMaterial in Schools) (Removal of Restrictions onUse) (England) Regulations, 2008

Repeals regulation 7 of the Education (Schoolsand Further and Higher Education) Regulations1989 and paragraph 7 of schedule I of theEducation (Special Educational Needs) (Approvalof Independent Schools) Regulations 1994 as faras England is concerned.

The Education (Hazardous Equipment andMaterials) (England) Regulations, 2004

Controls the use of radioactive substances in theFE sector in a similar way to the Education(Schools and Further and Higher Education)Regulations 1989 (England and Wales). Not yetrepealed.

The Carriage of Dangerous Goods and Use ofTransportable Pressure Equipment Regulations 2007

[comparable legislation is expected shortly in NorthernIreland]

Regulates transport of any radioactive substanceby road (not Northern Ireland). Relevant only ifradioactive substances are moved between sitesby public road.