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IAEA SAFETY STANDARDS SAFETY SERIES No.l

Safe Handling of Radionuclides

1973 Edition

Code of Practice sponsored by

IA E A and WHO

INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, 1973

This publication is no longer valid Please see http://www-ns.iaea.org/standards/

SAFE HANDLING OF RADIONUCLIDES1973 EDITION


SAFETY SERIES No. 1

SAFE HANDLING OF RADIONUCLIDES1973 EDITION

CODE O F P R A C T IC E

SPO N SO RED BY THE IN TERN ATIO N AL ATOM IC E N ER G Y AGENCY

AND TH E W O RLD H EA LTH ORGANIZATION

IN TERN ATIO N AL ATOM IC E N ER G Y AGENCY VIENNA, 1973


TH IS S A F E T Y S E R IE S W IL L ALSO B E PU BLISH ED IN FR E N C H , RUSSIAN AND SPANISH

SA F E HANDLING O F RAD IO N UCLID ES, 1973 ED ITIO N IA EA , VIENNA, 1973

STI/PU B /319

Printed by the IAEA in Austria March 1973


FOREWORDUnder i ts Statute the In tern ation al A tom ic E n erg y Agency is

em pow ered to provide fo r the application of stan d ard s o f safety fo r p ro tectio n ag a in st rad iatio n to i ts own o p eratio n s and to o p e ra tions m aking u se o f a s s is ta n c e provided by it o r with which it is o th erw ise d ire c tly a s s o c ia te d . To th is end au th o rities re ce iv in g such a s s is ta n c e a re re q u ired to o b serv e re le v a n t health and safety m e a su re s p re s c r ib e d by the Agency.

As a f i r s t s tep , it w as con sid ered an urgent ta sk to provide u s e r s o f rad ion u clid es with a m anual o f p ra c t ic e fo r the sa fe handling of th e se su b sta n ce s . The f i r s t edition o f su ch a m anual w as published in 1958 and re p re sen ted the f i r s t of the "Safety S e r ie s " , a s e r ie s of m anu als and codes on health and sa fe ty publish ed by the A gency. It was p rep ared a fte r c a re fu l co n sid eratio n o f e x is tin g n ational and in te rn a tio n a l cod es o f rad iatio n sa fety by a group of in te rn a tio n a l e x p e rts and in consu ltation with o th er in te rn a tio n a l bod ies.

It was sta ted in the forew ord to the f i r s t edition that th is Manual was issu ed by the Agency as a p ro v isio n al docum ent which would be s u b je c t to re v is io n fro m tim e to tim e and that com m ents subm itted to the In tern a tio n a l A tom ic E n erg y A gen cy 's S e c r e ta r ia t would be w elcom e. T h is edition p re sen ts the second re v is io n .

In re sp o n se to the suggestion made by som e M em b er S ta te s , the te rm 'ra d io iso to p e s ' has been changed to 'ra d io n u clid es ' in the tit le and, as ap p ro p ria te , in the te x t b ecau se the te rm 'rad io n u clid es ' in clu d es the rad io activ e e lem en t i t s e l f as w ell as the iso to p e s .

The s e r ie s o f m anu als and cod es published in the Safety S e r ie s and the T e c h n ic a l R e p o rts S e r ie s give m o re com p lete advice to the u s e r on sp e c ia liz e d to p ics .

It is recom m end ed that the Manual be taken into account as a b a s ic re fe re n c e docum ent by M em ber S ta te s of the Agency in the p rep aratio n of n ational health and safety docum ents co v erin g the u se o f rad io n u clid es.

T h is 1973 edition was p rep ared jo in tly by the S e c r e ta r ia ts of the W orld H ealth O rganization and the In tern atio n al A tom ic E n ergy Agency with the help of two con su ltan ts , M r. E . J . B en n ellick , H ealth and Safety B ra n ch of the UKAEA (IAEA con su ltan t), and P r o fe s s o r W. M ind er, C h ie f o f R adiation P ro te c tio n D iv ision , F e d e ra l O ffice of H ealth , B e rn e , Sw itzerland (WHO con su ltan t). M r. B en n ellick is now with the N ational R ad io lo g ica l P ro te c tio n B o a rd , H arw ell, United Kingdom .


ACKNOWLEDGEMENTST h e work o f th e fo llo w in g exp erts who form ed an in te rn a tio n a l p an el on th e sa fe h and ling o f

rad ion u clid es and whose work resulted in th e first ed itio n o f th is m a n u a l, is g rea tly acknow ledged . T h e A gency is also gra tefu l to th e consultants who revised th e m an u al and prepared th e present d ocum en t.

C h airm an

G . RandersIn stitu tt for A tom energ i Norway

M em bers

V .V . BochkarevA cad em y o f M e d ic a l S c ie n c e s o f the USSR Union o f S o v ie t S o c ia lis t Republics

H .J . D unsterU nited K ingdom A to m ic Energy Authority U nited K ingdom

B . GrossIn stitu to N a cio n a l de T e c n o lo g ia B ra z il

A . Hedgran

Radiofysiska Institu tion enSweden

F . H ercfkIn stitu te o f Biophysics C zech o slo v ak A cad em y o f S c ien ce s C zech o slo v ak S o c ia lis t Republic

H . Ja m m e tC en tre d* Etudes n u c l€ a ires de S a c la y Fran ce

P .N . K rishnam oorthy A to m ic Energy Establishm ent Ind ia

A .S . Rao

A to m ic Energy Estab lish m en t India

A .H .K . S la terU nited Kingdom A to m ic Energy Authority U nited K ingdom

F . W esternU nited S ta tes A to m ic Energy C om m ission U nited S ta tes o f A m erica

F . Y a m a sa k iS c ie n tif ic R esearch In stitu te Ltd .Japan

Observers

G . J . A ppletonU nited Kingdom A to m ic Energy A uthority U nited K ingdom

E . D iam ondU nited S ta tes A to m ic Energy C om m ission U nited S ta tes o f A m erica

R ep resentatives

L . DobsonW orld H ealth O rganization

E . H ellenIn tern a tio n a l Labour O rganisation

■CONSULTANTS’ M EETIN G IN 1971

M em b ers S c ie n t if ic S ecreta ries

E . J . B e n n e llick H .T . DawH ealth and Safe ty Branch o f the UKAEA IAEA

U nited K ingdomW . S ee le n ta g

W . M in d er WHO

R ad iation P ro tectio n D ivision F ed era l O ff ic e o f H ealth Sw itzerland


CONTENTS

CODE O F P R A C T IC E ...................................................................................... 1

1. INTRODUCTION ...................................................................................... 1

1 .1 . Scope ................................................................................................ 11 .2 . D e f in i t io n s ........................................................................................ 21 .3 . L im its of d oses fo r exp osu re to e x te rn a l

rad iatio n and rad io activ e contam ination ....................... 41 .4 . O rganization of rad iatio n sa fe ty .............................. .. 4

1 .4 . 1 . G en era l ........................................................................... 41. 4 . 2 . R esp o n sib ility o f the authority in ch arge

of the in s ta lla tio n ..................................................... 41. 4 . 3. D uties of the rad io lo g ica l health and

safety o ff ic e r ............................................................. 51 .4 . 4 . D uties of the w o r k e r ............................................... 6

1. 5. M ed ical su p erv ision of w o rk ers ......................................... 71 .5 . 1 . G en era l co n sid era tio n s ....................................... 71. 5. 2 . M ed ical exam ination b efo re em p loym en t. . . 81. 5. 3. M ed ical exam inations during e m p lo y m e n t.. 81 . 5 . 4 . M ed ical casu alty s e rv ic e ................... ................. 9

1. 6. D eterm in atio n o f rad ia tio n exp osu re o f p erso n n el . . 91. 6. 1. G e n e ra l c o n s id e r a t io n s ........................................... ' 91 . 6 . 2 . D eterm in atio n by p erso n n el m onitoring . . . . 101. 6. 3. D eterm in atio n by a re a m on ito rin g ................. 11

1. 7. G en era l a re a m o nitoring ....................................................... 121. 7 . 1 . M onitoring o f rad iatio n fro m e x te rn a l

so u rce s ........................................................ ".................. 121. 7. 2 . M onitoring o f contam in ation on s u r fa c e s

of ro o m s and e q u ip m e n t ......................................... 121. 7. 3. M onitoring o f a ir c o n ta m in a tio n ....................... 131 . 7 . 4 . M onitoring o f w ater contam ination ............... 131. 7. 5. M onitoring o f sk in and cloth ing ....................... 14

1 . 8 . R e co rd s ............................................................................................. 141 . 8 . 1 . P e rs o n a l h is to ry .............. ........................................ 141 . 8 . 2 . A rea m onitoring r e s u l t s ....................................... 14

2 . SE A L E D SO URC ES ................................................................................. 15

2 . 1 . C hoice and design o f sea led s o u rce s .............................. 152 . 2 . Methods o f u se o f s o u rce s ..................................................... 152 . 3 . Shielding ........................................................................................... 16


2 . 4 . S p e cia l u se s o f sea led so u rce s .......................................... 172 . 4 . 1 . L a rg e s o u rc e s and te le th erap y ..........................

in s ta lla tio n s in m ed ica l d e p a r tm e n ts ............. 172 . 4 . 2 . Sm all so u rce s fo r co n tact and in te r s t it ia l

therapy in m ed ica l d e p a r tm e n ts ....................... 182 . 4 . 3 . In d u stria l gam m a radiography ............................ 192 . 4 . 4 . T h ick n e ss gauges, s ta tic e lim in a to rs

and s im ila r d ev ices u sin g sea le d so u rce s . . 20

3. U N SEA LED SO U RC ES ....................... .................................................... . 21

3 . 1 . G e n e ra l o p eratio n s with u n sealed so u rce s ............ 213 . 2 . C h oice o f rad io activ e m a te r ia l and su itab le

p r o c e s s e s ........................................................................................... 253. 3 . C h oice and d esign of w orking p la ce s ................................ 26

3 . 3 . 1 . G en era l co n sid eratio n s ......................................... 263 . 3 . 2 . F lo o r s , w alls and working s u r f a c e s ............... 263. 3. 3 . Sinks ............................................................................. 273 . 3 . 4 . F u r n it u r e ......................................................................... 273 . 3 . 5 . L ig h t in g ............................................................................ 273 . 3 . 6 . V e n t ila t io n ................................................................. . . . 27

3 . 4 . P ro te c tiv e c lo th in g ...................................................................... 283 . 5 . P e rso n a l p ro tectiv e m e a su re s ........................................... 293. 6. C ontro l of a ir contam ination ......................................... ....... 303 . 7 . S p e c ia l u se s o f un sealed s o u r c e s ........... ............... 31

3. 7 . 1 . In sta lla tio n s fo r the u se o f rad io activ eg a ses ( e . g . radon) ............................ 31

3 . 7 . 2 . Lum inizing involving application o frad io activ e m a t e r i a l .................. .. 31

3 . 7 . 3 . M ed ica l u s e s o f u n sea led s o u rc e s . .*!: . . . . 333 . 7 . 4 . R ad ionu clid es in an im al exp erim en ts ........... 34

4 . STO RA G E O F SO U RC ES ....................................................................... 35

4 . 1 . P la c e o f s t o r a g e ............................................................................ 354 . 2 . Conditions o f s to rag e ............................................................... 364 . 3 . S torage o p eration s .................................................................... 37

5. TRAN SPO RTA TIO N O F RADIOACTIVE M A T E R IA L .......... 37

5 . 1 . T ran sp o rta tio n within an e stab lish m en t ....................... 375 . 2 . T ran sp o rta tio n outside an e sta b lish m e n t .................... 39


6. A C CID EN TS ............................................................................................... 39

6 . 1 . Id en tifica tio n of a cc id en ts ...................................................... 396 . 2 . P reca u tio n a ry m e a s u re s ........................................................ 396. 3. A ctions com m on to a ll a cc id e n ts ............................. 406 . 4 . A ccid en ts involving rad io activ e c o n ta m in a tio n ......... 416. 5. A ccid en ts involving only e x te rn a l rad ia tio n ................ 43

7. DECONTAM INATION ........................................................................... 43

7 . 1 . D econtam ination o f p erso n n el .............................................. 437. 1 . 1 . M e asu re s to be taken in c a s e of in te rn a l

contam ination o f p erso n n el ................................. 447 . 1 . 2. M e asu re s to be taken in c a s e o f e x te rn a l

contam ination of p erso n n el ................................. 447i 2 . D econtam ination of equipm ent .......................................... 46

7 . 2 . 1 . D econtam ination of g la ssw a re and to o ls . . . 467. 2 . 2 . D econtam ination o f w orking a r e a s ,

b en ch e s, e tc ..................................................................... 477 . 2 . 3 . D econtam ination o f clo th in g , hosp ital

lin en and s im ila r ite m s ............................ ............ 48

8 . R A D IO A C TIVE W A STE CO N TRO L AND D ISPO SA L .............. 49

8 . 1 . W aste co lle c tio n .......................................................................... 498 . 2 . W aste s to ra g e ............................................................................... 508. 3. E fflu en t r e le a s e to the e n v ir o n m e n t................................. 51

8 . 3 . 1 . G en era l co n sid era tio n s ........................................ 518 . 3. 2 . E fflu en t r e le a s e to d ra in s and s e w e r s ............ 528 . 3. 3. E fflu en t re le a s e to the atm osp here ............... 538. 3. 4 . B u ria l o f w aste .......................................................... 538 . 3 . 5 . In cin eratio n of w aste ............................................. 54

A P P E N D IC E S ................................................ ......................................................... 55

A P PEN D IX 1D ERIV ED CONCENTRATION L IM IT S OF RADIONUCLIDES IN AIR AND W A TER FO R OCCUPATIONAL E X P O SU R E ____ 55

A P P EN D IX 2MAXIMUM P E R M IS S IB L E L E V E L S FO R SU R FA C E CONTAMINATION .............................................................................................. 84


CODE OF PRACTICEIm p ortan t N ote:

Throughout the C ode, th e word ’m ust' is used to in d ic a te an e sse n tia l req u irem en t, w hereas the word 'should' in d ica te s a desirab le req u irem en t.

1. INTRODUCTION

1 . 1 . SC O PE

1 . 1 . 1 . Thi s Code of P r a c t ic e is provided as a guide to the sa fe handling of rad io n u clid es . It is hoped that it wi l l prove helpful p a rticu la r ly to s m a l l - s c a l e u s e r s who m ay not have d ire c t a c c e s s to s p e c ia lis t so u rce s of in form ation .

1 . 1 . 2 . L a r g e -s c a le u s e rs and those with sp e cia liz e d ex p e rien ce m ay p re fe r to adopt o th er p ro ced u res that a re known to provide equivalent o r even su p e rio r p ro tectio n . O ther published guides can be recom m ended, when appropriate, to sp e cia liz e d fie ld s of ap p lica tion . It is p resum ed that those using rad ion u clid es in the p ra c t ic e of th e ir p ro fe ss io n (ra d io lo g is ts , e t c . ) w ill supplem ent the re c o m m endations o f the Code by application of th e ir n orm al p ro fe ss io n a l tra in in g .

1 . 1 . 3 . The prom ulgation of th is Code is not, of co u rse , intended to p reclu d e the ap p lication of any m ore strin g en t and m ore exten siv e in stru ctio n s that may be in .fo rc e in som e co u n trie s .

1 . 1 . 4 . The Code contains a s e r ie s of recom m end ations which should be in te rp re te d with s c ie n tif ic judgem ent in th e ir application to a p a r t ic u la r p ro b lem . T h e ir wording is in tentionally p re c is e and the u s e r m u st understand the im p lica tio n o f any recom m end ation b efo re d eviating fro m it . The re q u irem en ts as laid down in th is Code are fo r the handling of sea led and unsealed so u rce m a te r ia ls in a p ro p e rly designed la b o ra to ry . Thus the u se o f sea led and unsealed rad io activ e m a te r ia l in the fie ld , e .g . t r a c e r e x p e rim e n ts , e tc . ,is ou tside the scop e of th is Code, though m any o f the p rin cip le s hold.

1 . 1 . 5 . S ince m o st n atu ra l o b je c ts contain som e rad io activ e m a te r ia l, it is to be understood that the recom m end ations in the Code a re not intended to apply below a c e r ta in lim itin g d eg ree of rad io activ ity .The low er l i mi t can be taken as 0 . 0 0 2 «C i pe r gram of m a te r ia l.

1


H ow ever, fo r pu rp oses o f n otifica tion , re g is tra tio n o r l ice n s in g , the low er l im it should be th a t p re scr ib e d in the A gen cy 's B a s ic Safety Standards fo r R adiation P ro te c tio n (1967 E d itio n )1 , Annex A,T ab le II, la s t colum n. A guide to the q u antities w hich m ay sa fe ly be handled in d iffe ren t types of working p lace is provided in T ab le II and 3. 1. 12. below . In g e n era l, any re la x a tio n of co n tro ls m u st be b ased on an a s s e s sm e n t o f the p o ss ib ility o f h azard , taking into accou nt the natu re of the m a te r ia l, o p eratio n s and w orking fa c i l i t ie s . It i s recom m end ed , how ever, that a l l rad ion u clid es should be tre a te d a s p o ten tia lly dangerous b ecau se o f the tra in in g value o f th is approach and the p ro te ctio n if o ffe rs ag a in st m i s - id en tifica tio n .

1 . 1 . 6 . The B a s ic Safety Standards p re s c r ib e m axim um p e rm is s ib le le v e ls of exp o su re to rad iation and fundam ental op eration al p r in c ip le s . They should be followed and s tr ic t ly ob served by a ll w o rk ers exposed to o r using rad ia tio n s o u rc e s . T h is Code g ives m ore d etailed guidance fo r im plem enting the re q u irem en ts o f the B a s ic Safety Standards fo r u s e rs of rad io n u clid es. C r o s s -r e fe r e n c e to the B a s ic Safety Standards is thus unavoidable if duplication is to be kept to a m inim um .

1 . 2 . D EFIN ITIO N S

1 . 2 . 1 . G e n e ra l. The te ch n ica l t e r m s used in th is Code have th e ir accep ted s c ie n tif ic m eanings. D efin itions of c e r ta in te rm s a re provided in 1. 2 . 2 . - 1 . 2 . 1 4 . below .

1 . 2 . 2 . Ionizing ra d ia tio n : e le c tro m a g n e tic o r co rp u scu la r ra d iation cap ab le of producing ions d ire c tly o r in d ire ctly in its passage through m a tte r ( e . g . alpha ra y s , beta ra y s , g a mma ra y s , X -r a y s , n e u tro n s).

1 . 2 . 3 . Sealed s o u rc e : a sou rce of ionizing rad iatio n that is firm lybonded w ithin m a te r ia l o r sealed in a co v er of su ffic ie n t m ech an ica l stren g th to exclud e the p o ss ib ility of contam in ation by o r contact with the rad ionu clid e and of d isp ersio n of the rad io activ e m a te r ia l into the environm ent under fo re se e a b le conditions of use and w ear.

1 . 2 . 4 . U nsealed s o u rce : a so u rce w hich is not a sea le d so u rce and w hich under n o rm al conditions o f use can produce contam in ation .

1 S a fe ty Series N o. 9.

2


1 . 2 . 5 . E x te rn a l ra d ia tio n : rad iatio n reach in g the body from so u rce s e x te rn a l to i t .

1 . 2 . 6 . In te rn a l ra d ia tio n : rad iatio n reach in g the body from ra d io activ e so u rc e s w ithin it .

1 . 2 . 7 . C u rie f Ci ) : the unit of activ ity is the c u r ie . One cu rieequ als 3 . 7 X 1010 d is in teg ra tio n s s " 1.

1 . 2 . 8 . R ad io activ e con tam in atio n : the un d esired p re se n ce ofrad io activ e su b stan ces in o r on any p erson o r m a te r ia l.

1 . 2 . 9 . Adequate p ro te c tio n : pro tectio n ag a in st e x te rn a l rad iatio nand again st intake of rad io activ e m a te r ia l such that the rad ia tio n dose re ce iv e d by any p e rso n o r the population as a w hole, fro m s o u rc e s e x te rn a l and/or in te rn a l to the body, sh a ll not exceed the m axim um p e rm is s ib le d oses o r dose lim its p re s c r ib e d in the re g u la tio n s and recom m end ations se t fo r rad iatio n exposure by the com petent au thority .

1 . 2 . 1 0 . In s ta lla tio n : any accom m od ation o r fa c ility designed fo rhandling rad io activ e su b sta n ce s , including the production, p ro ce ss in g , u se o r s to ra g e of such su b stan ces.

1 . 2 . 1 1 . E n clo sed in s ta lla tio n : an in sta lla tio n in w hich the rad iatio nso u rce and a ll o b je c ts exposed th ere to a re w ithin a perm anent e n c lo su re :

(a) T o w hich no p e rso n has a c c e s s , o r w ithin which no p erson (ex cep t those undergoing trea tm en t) is p erm itted to re m ain during irra d ia tio n ; and

(b) W hich afford s under a ll p ra c t ic a l op erating conditions adequate p ro te ctio n fo r a ll p e rso n s outside the e n c lo su re .

1 . 2 . 1 2 . Open in s ta lla tio n : an in sta lla tio n w hich, on accou nt ofo p eratio n al re q u ire m e n ts , e . g . the use of m obile equipm ent, does not me e t the conditions sp ecified fo r an en clo sed in sta lla tio n .

1 . 2 . 13. C om petent authority : a national o r in tern a tio n a l authoritywhose ju r isd ic tio n ap p lies to the a c tiv itie s of the in sta lla tio n .

1 . 2 . 14. C ontro lled a r e a ; an a r e a scheduled as such fo r the p u rpose of co n tro llin g individual p erso n a l exp o su re , and under the su p erv is io n o f a p erso n who has the knowledge and re sp o n sib ility to apply ap p rop riate rad ia tio n p ro tectio n reg u la tio n s.

3


1 . 3 . L IM IT S O F DO SES FO R E X P O SU R E TO E X T E R N A L RADIATION AND RAD IO ACTIVE CONTAMINATION

1 . 3 . 1 . A ll the w ork perform ed in in sta lla tio n s using rad ionu clid es m u st com ply with the m axim um p e rm is s ib le d oses fo r w o rk e rs , and m ust not lead to exp osu re o f individual m em b ers of the public o r o f the population as a whole to rad iatio n in e x c e s s o f the dose lim its p re s c r ib e d in the A g e n cy 's B a s ic Safety Standards fo r R ad iation P ro te c tio n 1, b earin g in mind the o v errid in g re c o m m endation that actu a l exposure should be as fa r below the dose lim its as is re a d ily ach iev able and that any u n n ece ssa ry exposure should be avoided.

1 . 3 . 2 . A m axim um p e rm iss ib le lev e l has often not been g en era lly accep ted with re s p e c t to c e rta in sp e c ific s itu atio n s, p a rticu la r ly in re la tio n to s u rfa ce contam ination o r w aste d isp o sa l. The p roblem s involved and u sefu l w orking guidance a re s e t fo rth in the re lev an t se c tio n s of th is Code.

1 . 4 . ORGANIZATION O F RAD IA TIO N S A F E T Y 2

1 . 4 . 1 . G e n e ra l. Good rad iatio n sa fe ty p ra c t ic e depends on an e ffe c tiv e health and sa fe ty organ ization . E x p e rie n ce shows that even the m ost com petent w o rk er cannot be re lie d upon to keep in mind a ll health and safe ty req u irem en ts while p reoccu pied with the s u c c e s s fu l p erfo rm an ce of his w ork. R e sp o n sib ilitie s and duties m ust be s e t out c le a r ly to ensu re sa fe ty .

1 . 4 . 2 . R esp o n sib ility of the authority in ch arge of the in s ta lla tio n :The authority in ch arg e of the in sta lla tio n is cu sto m arily held r e sp on sib le fo r the ra d io lo g ica l sa fe ty of both the w o rk ers and the g e n era l p u blic . To m eet those re sp o n s ib ilit ie s it m ust en su re that the actio n is taken in acco rd an ce with 1. 4 . 2 . 1 . - 1 . 4 . 2 . 7. below.

1 . 4 . 2 . 1 . H ealth and sa fe ty ru le s (in conform ity with th is Code) a re to be p rep ared fo r the a re a s in which rad io activ e m a te r ia l is to be handled.

1 . 4 . 2. 2. A ll n e c e s s a ry op erating in stru ctio n s a re to be provided.

1 S a fe ty S erie s N o. 9.2 S e e also : T h e Provision o f R ad io lo g ica l P ro tectio n S erv ic e s , S a fe ty Series N o. 13 ,

IA EA , V ien n a (1 9 6 5 ).

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1 . 4 . 2. 3. Suitable in sta lla tio n s and equipm ent a re to be provided.

1. 4 . 2 . 4 . P ro v is io n is to be made fo r the n e c e s s a ry m ed ica l s u p e rv is io n of the w o rk e rs and fo r a su itab le m ed ica l casu alty s e r v ic e .

1 . 4 . 2. 5. Only p erso n s who a re m ed ica lly su itab le and adequately tra in ed o r exp erien ced a re to be allow ed to w ork with rad io activ e m a te r ia l.

1 . 4 . 2. 6. A ll w o rk e rs lia b le to exp o su re to ionizing rad ia tio n in the co u rse of th e ir w ork a re to be in stru cted about the health hazard s involved in th e ir d u ties. Su itable tra in in g with re fe re n c e to health and sa fe ty is to be provided fo r a ll s ta ff .

1 . 4 . 2 . 7. A p erso n tech n ica lly qualified to ad vise on a ll points of rad ia tio n sa fe ty is to be em ployed o r o th erw ise provided. In th is Code he is re fe r re d to as the "ra d io lo g ic a l health and sa fe ty o ffice r" , although o th er t i t le s a re cu sto m arily used as w ell. The authorityin ch arg e of the in s ta lla tio n m ust consu lt th is o f f ic e r on a ll points of rad ia tio n sa fe ty , and m e a su re s m ust be taken to en su re that a ll p erso n s who m ay be exposed to rad ia tio n hazard s know his nam e and how to get in touch with hi m. A lte rn a te s to him should be provided as n e c e s s a ry .

1 . 4 . 3 . D uties of the ra d io lo g ica l health and sa fe ty off ic e r : Thera d io lo g ica l health and safety o f f i c e r 's duties w ill v ary som ewhat acco rd in g to the org an iza tio n a l s tru c tu re of the group with which he is w orking and the d egree of hazard p resen ted by the c la s s of work un dertaken . In g e n e ra l, he w ill a s s is t the authority in ch arg e to c a r r y out the la t t e r 's re s p o n s ib ilit ie s fo r rad ia tio n p ro te ctio n . In c a rry in g out h is d uties, the ra d io lo g ica l health and sa fe ty o f f ic e r should c a l l fo r advice o r help fro m p ro fe ss io n a lly com petent p erson s w henever n e c e s s a ry . His w ork w ill usu ally include th e duties p r e sc r ib e d in 1. 4 . 3 . 1. - 1 . 4 . 3 . 1 0 . below .

1 . 4 . 3 . 1 . Any n e c e s s a ry ad m in istra tiv e and te ch n ica l in stru ctio n s con cern in g the rad ia tio n hazard s and sa fe w orking p ra c t ic e s r e le vant to the nature of the in s ta lla tio n and w ork should be given to a ll em p loyees whose duties involve the handling of rad io activ e m a te r ia l and to a ll o th er em p loy ees who a re not re g u la rly em ployed in such work but who m ay o cca s io n a lly be exposed to rad ia tio n and rad io activ e m a te r ia l. T h e se in stru ctio n s should be w ritten , u n d erstand able , p ra c t ic a b le and, w henever p o ss ib le , posted as n o tice s .

1 . 4 . 3. 2. A ll p erso n s w orking with rad io activ e m a te r ia ls m ust be in stru cted in the u se o f a ll n e c e s s a ry safeg u ard s and p ro ced u res

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and a ll v is ito r s should be inform ed of p ertin en t p recau tio n s to be taken . A ll such w o rk ers and v is ito rs m ust be supplied with such a u x ilia ry d ev ices as m ay be n e c e s s a ry fo r p ro tectio n . The ra d io lo g ica l health and sa fe ty o f fic e r m ust en su re that ev ery v is ito r has a p ro p er authorization ; no u n n ece ssary v is its should be m ade.

1 . 4 . 3. 3. R ad io activ e m a te r ia l (including that in p atien ts , an im als and equipm ent) should be prevented from leav ing the ju r isd ic tio n of the authority in ch arg e under c ircu m sta n ce s that may s u b je c t o ther p erso n s to rad ia tio n in e x c e s s of the lim its p re s c r ib e d by the co m petent au thority . The rad io lo g ica l health and sa fe ty o f f ic e r should en su re that the p ro p er a rran g em en ts fo r the sa fe d isp o sa l of w aste a re m ade.

1 . 4 . 3. 4. M easu res m ust be taken to en su re that no a re a , w hether insid e o r outside the in sta lla tio n , is su b je c t to rad iatio n le v e ls or co n cen tra tio n s of rad io activ e m a te r ia l exceed ing the m axim um p e r m is s ib le le v e ls indicated by the com petent authority fo r an a re a of the type con cern ed .

1 . 4 . 3. 5. The ap p rop riate au th o rities (e . g. the f ire departm ent) m ust be notified of the e x is ten ce of any conditions o r situ ation s that, w hile not n orm ally con sid ered a rad iatio n hazard , m ay b ecom e a hazard in s p e c ia l o r unusual c irc u m sta n c e s .

1 . 4 . 3. 6. M easu res m ust be taken to en su re that no m od ification of equipm ent o r in sta lla tio n s w hich m ight lead to u n fo reseen rad iation hazard s is made without the p ro v ision of appropriate sa feg u ard s.

1. 4 . 3 . 7. M e asu re s m ust be taken to en su re that no rad io activ e m a te r ia l is d ealt with by unauthorized p erson s in the in sta lla tio n .

1 . 4 . 3 . 8 . M easu res m ust be taken to e n su re , by the p ro v isio n of su itab le a lte rn a te s to the rad io lo g ica l health and safety o f fic e r or by o th er m ean s, that n e c e s s a ry advice is av a ilab le at a ll t i me s in ca se of an em erg en cy and that the p a rtic u la r sa fe ty m e a su re s to be taken in such c a s e s a re provided fo r .

1 . 4 . 3 . 9 . Su itable re c o rd s m ust be kept.

1 . 4 . 3 . 1 0 . M onitoring, m ed ica l su p erv isio n and p ro tectio n m e asu re s m ust be c a r r ie d out to the n e c e s s a ry extent and p ro p erly co -ord in ated .

1 . 4 . 4 . Du tie s of the w o rker

1 . 4 . 4 . 1 . The w o rk er should know the op erating in stru ctio n s provided.

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1 . 4 . 4 . 2. He should be fa m ilia r with and o b serv e the health and sa fe ty ru le s fo r h is a r e a .

1 . 4 . 4 . 3 . The sa fe ty equipm ent provided m ust be used p ro p erly .

1 . 4 . 4. 4. T he w o rk er should p ro te ct both h im s e lf and o th ers by actin g ca re fu lly at a ll tim e s and w orking sa fe ly .

1 . 4 . 4. 5. Any accid en t, unusual incid ent o r p e rso n a l in ju ry , howe v e r s lig h t, m ust be rep o rted .

1 . 4 . 4 . 6 . W o rk ers exposed to rad iatio n h azard s should im m ed iate ly re p o rt any sig n ifican t a ilm en t, any suspected o v er-e x p o su re to e x te rn a l rad ia tio n o r any susp ected intake of rad io activ e m a te r ia l into th e ir b od ies.

1 . 5 . M ED ICA L SU PERV ISIO N O F W O R K E R S3

1 . 5 . 1 . G en era l co n sid era tio n s

1. 5 . 1 . 1. T he m ed ica l su p erv is io n of p e rso n s em ployed in rad iatio n w ork should be based on the ex p erien ce that in any p ro p erly co n ducted rad ia tio n la b o ra to ry rad ia tio n accid en ts w ill be seco n d ary to ord in ary in d u stria l a cc id e n ts . P re-em p lo y m e n t and routine m ed ica l exam in ation s should be p r im a rily those d e s ira b le in good in d u stria l m ed ica l p ra c t ic e , but c e r ta in m ed ica l req u irem en ts a re s p e c ific to rad ia tio n w ork and should supplem ent re g u la r in d u stria l m ed ica l p r a c t ic e . O pportunities fo r o b serv atio n of genuine sym ptom s of rad ia tio n in ju r ie s w ill be e x tre m e ly ra re u n less v ery bad w orking conditions p re v a il. U n d esirab le working conditions m ay be p resen t to a co n sid erab le d egree b e fo re any c lin ic a l sym ptom s of rad iatio n dam age ap p ear.

1 . 5 . 1 . 2 . P e rs o n s below the age of 16 m ust not be occu pationally exposed to rad ia tio n . In many co u n tries the m inim um age is18 y e a r s .

1 . 5 . 1 . 3 . S p e cia l atten tion should be d irected toward p ro tectin g women of rep ro d u ctive cap acity .

1 . 5 . 1 . 4 . If X - r a y exam in ation s a re c a rr ie d out, c a re should be taken to keep the exp osu re entailed to a mi ni mum.

3 For a d d itio n al in fo rm atio n see : M e d ica l Supervision o f R ad iation W orkers, S a fe ty S erie s No. 2 5 , IAEA, V ien n a (1 9 6 8 ).

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1 . 5 . 2 . M ed ical exam ination b efo re em ploym ent

1. 5 . 2 . 1. A p erso n mus t not be em ployed on w ork en ta ilin g a p o ssib le rad ia tio n hazard un less, w ithin two months p reced ing h is f i r s t e m ploym ent on that w ork, o r sh o rtly a fte r such f i r s t em ploym ent, he has undergone an ap p rop riate m ed ica l exam ination .1 . 5 . 2. 2. It i s recom m end ed that th is m ed ica l exam ination on re cru itm e n t should include the follow ing:

(a) A com plete m ed ica l exam ination , taking into co n sid eratio n the w ork on which the p erso n is to be em ployed, including a p erso n al h is to ry cov erin g fam ily , m ed ica l and occu p ational background, and the usu al c l in ic a l te s ts ; and

(b) S p e cia l in v estig atio n s of those organs and functions which a re regard ed as p a rticu la r ly v u ln erab le to rad ia tio n hazard s in the light of the c la s s of w ork to be undertaken, e . g . by m eans of h aem ato lo g ica l, d erm ato lo g ica l, op hthalm ological, pulm onary, g y n aeco lo g ica l o r n eu ro lo g ica l exam in ation s.

1 . 5 . 3 . M ed ical exam in ation s during em ploym ent

1 . 5 . 3 . 1 . A ll p erso n s em ployed in w ork involving rad iatio n hazard s should undergo m ed ica l exam in ation s.

1 . 5 . 3. 2. Routine m ed ica l exam inations during em ploym ent should be c a r r ie d out p e rio d ica lly as the com petent authority may re q u ire . They should include the g e n era l exam inations p ractice d in in d u stria l m ed icine and a lso sp e c ia l exam inations d e s ira b le b ecau se of the h azard s of e x te rn a l rad ia tio n and contam ination in each p a rticu la r c a s e . S p e c ia l exam in ation s as indicated in 1 . 5 . 2 . 2 . ( b ) above should be c a r r ie d out at ap p rop riate in te rv a ls . In addition to routine m e d ica l exam ination , excep tion al m ed ica l su rv e illa n ce , com p risin g any fu rth e r exam in ation s, d econtam ination p ro ced u res o r urgent m ed ica l trea tm en t deem ed n e c e s s a ry by an app rop riate m ed ica l p ra c t it io n e r m ust be provided. Any w o rk er re ce iv in g an acc id en ta l o r em erg en cy dose g r e a te r than tw ice the m axim um p e rm iss ib le dose m u st be su b jected to excep tion al m ed ica l s u rv e illa n ce . The p h ysician should sp ecify any req u ired p rogram of exam in ation s.

1 . 5 . 3. 3. In c a s e s of in te rn a l rad io activ e contam ination , the rad io - to x ico lo g ic a l exam in ation s should be designed to provide in form ation on the natu re and extent o f such contam ination by m eans of m e a s u re m ents and an a ly ses c a r r ie d out d ire c tly on the organ ism and in d ire c tly on the e x c re ta (u rin e, faeces, exhaled a ir ) . In addition, in c a s e s of inhalation o f a e ro s o ls , rad io activ e dust o r g a s e s , the exam in ation of the lungs should include the in v estigation of com bined m e ch a n ica l, ch e m ica l o r rad io activ e e ffe c ts .

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1. 5 . 3 . 4 . In the c a s e o f w o rk e rs handling un sealed rad io n u clid es, te s ts a re u sefu l fro m tim e to tim e to d eterm in e the to ta l body burden; in m any c a s e s m onitoring the e x c r e ta (m ore p a rticu la r ly the u rin e o r , in the ca se of rad ium , the radon in the b reath ) w ill p e rm it an a s s e s s m e n t of the body burden. In c e r ta in c ir c u m s ta n ce s a m o re e la b o ra te te s t can be adopted to d eterm in e the body burden by m easu rin g the g a mma rad ia tio n (o r b rem sstrah lu n g ) em itted by the body. I f it is p o ssib le to m easu re such a body burden, the dose of rad ia tio n re ce iv e d should be estim ated , noted on the p e rso n n el re co rd and taken into accou nt by the p h ysician .

1 . 5 . 4 . M ed ical casu alty s e r v ic e

1 . 5 . 4 . 1. The form of m ed ica l casu alty s e r v ic e provided w ill depend on the a v a ila b ility o f m ed ica l s ta ff w ithin the e sta b lish m e n t.

1 . 5 . 4. 2. F i r s t - a id advice and equipm ent m ust be im m ed iately a v a ilab le throughout the w orking a r e a . The scope of the f i r s t -a id tre a tm e n t attem pted m ust be based on m ed ica l ad vice.

1 . 5 . 4. 3. The a rran g em e n ts fo r r e fe r r in g ca s u a ltie s and p erson n el contam in ation p ro b lem s to the m ed ica l s e r v ic e at an ap p rop riate stag e should be c le a r ly laid down and knownto the p e rso n s co n cern ed .

1 . 6 . D ETERM IN A TIO N O F RADIATION E X P O SU R E O F P E R SO N N E L 4

1 . 6 . 1 . G e n e ra l co n s id e ra tio n s . The e ss e n tia l aim o f rad io lo g ica l p ro tectio n is to prevent in ju ry fro m ionizing rad ia tio n . Its b a s is is a re s p e c t fo r the recom m ended m axim um p e rm is s ib le d o se s . P h y s ic a l o r ra d io ch e m ica l techniqu es p e rm it the m easu rem en t of v e ry low rad ia tio n d oses and q u antities of rad io elem en ts ; th is s e n sitiv ity is v e ry help fu l, as it en ab les the d etection o f ir r a d ia tion co n sid era b ly low er than that con sid ered p e rm is s ib le . The m eth o d ical application of th e se techniqu es should th e re fo re be reg ard ed as e s s e n tia l. T h e se tech n iqu es m ay b e c la s s if ie d as fo llo w s.

1 . 6 . 1 . 1 . P e rso n n e l m onitoring co n sistin g of:(a) E x te rn a l rad ia tio n m onitoring , in which rad ia tio n m easu rin g

d ev ices a re w orn by the w o rk er; and

4 For ad d itio n al in fo rm a tio n , th e reader is referred t o : S a fe H andling o f Radioisotopes,H ealth Physics A ddendum , S a fe ty S er ie s No. 2 , IA EA , V ie n n a (1 9 6 0 ) , to be published in revised form in 197 3 under th e t i t le 'R ad iatio n P ro te ctio n P ro ced u res '; T h e Provision o f R ad io lo g ica l P ro tectio n S erv ic e s , S a fe ty S erie s No. 1 3 , IA EA , V ien n a (1 9 6 5 ) ; T h e Basic Requirem ents for Personnel M on itorin g , S a fe ty S erie s No. 1 4 , IA EA , V ie n n a (1 9 6 5 ).

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(b) In te rn a l contam in ation m onitoring , in w hich su itab le in stru m en ts m ay be used , o r the body w astes m ay be sam pled and analysed , to -d eterm in e the p re se n ce and quantity of rad io activ e m a te r ia l within the body.

1. 6 . 1. 2 . A rea m onitoring involving the d eterm in ation of rad iatio n le v e ls and a ir contam ination in the w orking a r e a by:

’ (a) M easu rem en t, using rad iatio n m easu rin g in stru m en ts and d ev ice s ; and

(b) C alcu lation , based on the amount of rad io activ e m a te r ia l p re se n t, its form and the nature of the p r o c e s s e s in which the w o rk e rs w ill be exposed .

1 . 6 . 2 . D eterm in atio n by p erso n n el m onitoring

1 . 6 . 2 . 1 . M onitoring fo r e x te rn a l rad ia tio n exp osu re with p erson n el d o s e m e te rs . T h is s im p le and convenient method should be used fo r the m easu rem en t of e x te rn a l rad iatio n exp osu re of a l l w o rk ers in the co n tro lled a re a . The com m only used device is the film d ose- m e te r , which p e rm its m easu rem en t of the cum ulative e x te rn a l rad ia tio n exp osu re o v er a p eriod . T h is film a lso provides a p e r m anent m eans of checking the re co rd which should be kept of the cum ulative e x te rn a l rad ia tio n to which each individual has been exposed . In addition, the film when used in a su itab le h old er p ro vid es in form ation about the quality of rad ia tio n . S im ila r film d o sem e te rs should be used on the w r is ts , hands o r o th er e x tre m itie s when th e se a re exposed to h igher rad iatio n fie ld s than is the trunk of the body. T h erm o lu m in escen t d o se m eters a re now com m only used on th e w r is ts , hands and fin g e rs . P o ck et ion ization ch am b e rs , individual lu m in escen t and o th er so lid -s ta te rad ia tio n d e te c to rs and th im ble ch am b e rs supplem ent film d o se m eters and a re p a rticu la rly u sefu l w here an im m ed iate and sen sitiv e m easu rem en t is needed in conn ection with a sp e c ific ta sk . S erio u s e r r o r s m ay, how ever, o ccu r u n less standard p ro ced u res a re adopted in the use o f d o se m e te rs fo r p erso n n el m onitoring .

1 . 6 . 2. 2. M onitoring fo r in tern a l co n tam in atio n . The d ifficu ltie s of th is fo rm o f m onitoring a re v ery r e a l b ecau se of the com p licated and sp e c ia liz e d nature of the techniqu es involved. In the c a s e of m onitoring body w astes by ra d io ch e m ica l a n a ly sis , th e re a re fu rth er d ifficu ltie s in in te rp re tin g the re s u lts with reg ard to:

(a) M onitoring by in stru m en ts . W hole-body o r gamm'a- sp e c tro m e try rad ia tio n d e te c to rs may be used to d eterm in e the p re se n ce and quantity o f rad io activ e m a te r ia l in the body. Howe v e r , th ese in stru m en ts a re expensive and th e ir op eration and the

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in te rp re ta tio n of the re s u lts obtained from them a re sp e cia liz e d ta s k s . It is un likely that s m a ll u s e r s would own such in stru m en ts, though in sp e c ia l c a s e s the use of in stru m en ts owned by o th er in s t i tutions could be a rran g ed . O ften, how ever, s im p le apparatus can be used in the in d iv id u a l's ow nw orking p lace without re fe re n c e to a sp e c ia liz e d la b o ra to ry . T h is is advantageous p a rticu la r ly in a c cident s itu ation s when it is im portant to m ake a m easu rem en t, even a rough one, as quick ly as p o ssib le ; and

(b) M onitoring by a n a ly sis o f body w aste . A routine p rogram o f u rin e an a ly sis should be drawn up fo r w o rk e rs lik e ly to be e x posed to s ig n ifica n t in te rn a l contam ination . The freq u en cy of u rin e sam p ling should be d eterm ined on the b a s is of an ap p ra isa l of the natu re and quantity of the rad ionu clid es involved and the o p eratio n s involved in the p a r tic u la r p r o c e s s . In the event of su sp ected in te rn a l contam ination a sp e c ia l s e r ie s of sam p les should be taken and analysed , i f ap p rop riate . The b io lo g ica l h a lf - l ife and the period o f body re ten tio n should be b orn e in mind in scheduling the taking o f th ese sa m p le s . W here ap p rop riate , u rin e an aly sis should be supplem ented by faecal a n a ly sis , nose sw abbing, ex a m in a tion o f stom ach w ashings and b rea th te s ts .

1 . 6 . 3 . D eterm in atio n by a r e a m onitoring . The d eterm in ation of rad ia tio n exp o su re of p erso n n el by a re a m onitoring o r ca lcu la tio n should be used as a la s t r e s o r t ; w henever p o ss ib le , individual d o s im e te rs should be used .

1 . 6 . 3 . 1 . M onitoring by in s tru m e n ts . The u se of ion ization ch am b e rs , pocket ion izatio n ch am b ers , film d o se m eters and so lid - s ta te d ev ices , exposed under conditions s im ila r to those in w hich the w o rk e rs w ill be exposed , en ables the dose to an individual o v er any p a r t ic u la r tim e to be in fe rre d . M easu rem en ts of contam ination p re sen t in inhaled a ir o r ingested m a te r ia l can be used to e stim a te p o ssib le body uptake. However, co n sid erab le e r r o r s w ill o ccu r, e s p e c ia lly if the m e asu re m e n ts a re not re p re se n ta tiv e b ecau se of the p re se n ce of p a r t ic le s o f high s p e c if ic activ ity .

1 . 6 . 3. 2. M onitoring by ca lcu la tio n . A knowledge o f the to ta l quantity of rad io activ e m a te r ia l p re sen t, the nature of that m a te r ia l, the p ro c e s s e s being used and the w orking conditions in a lab o ra to ry en ab les the p o ssib le exp o su re of p erson n el to be e stim ated . Howe v e r , such estim a tin g c a lls fo r co n sid erab le ex p e rien ce and te c h n ica l s k il l .

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1 . 7 . G EN ERA L A R EA MONITORING

In addition to p erso n n el m onitoring to d eterm in e the rad iation exp o su re h is to ry of individuals, g en era l a re a m onitoring is c a rr ie d out to d eterm in e the need fo r p ro tectiv e actio n . M onitoring should be done p e rio d ica lly o r continuously, depending upon the e x te rn a l and in te rn a l rad ia tio n h azard s, fo r the purpose of d eterm in ing the p o ss ib ility o f exposure to rad iatio n of p e rso n s , w orking p la ces and a r t ic le s , b earin g in mind that s p e c ia l types of w ork, e .g . low -lev el counting, m ay re q u ire m ore strin g en t p recau tio n s.

1 . 7 . 1 . M onitoring of rad ia tio n from e x te rn a l so u rce s

1. 7. 1. 1. A ll p la ces around rad io activ e so u rce s em ittin g p enetrating rad ia tio n w here p erso n s can be exposed to rad iation , not neglecting ad joining ro om s o r p la ce s outside the building, m ust be m onitored fo r rad ia tio n . T h is should be done b efo re s ta rtin g a p ro je c t , a fte r any sig n ifican t m o d ification of the se t-u p fo r it and a lso p erio d ica lly w hile it is being c a rr ie d out.

1. 7. 1 . 2 . P o rta b le ion ization ch am b e rs , pocket ion ization ch am b ers , G e ig e r-M fllle r co u n ters , sc in tilla t io n co u n ters , solid s ta te d ev ices and in som e c a s e s film d o se m eters may be used . A ll in stru m en ts used fo r m onitoring m ust be ca lib ra te d and checked re g u la rly , fo r w hich purpose a rad iatio n standard should be a v a ila b le . D uplication of in stru m en ts is d e s ira b le in som e c a s e s .

1 . 7 . 2 . M onitoring of contam ination on s u r fa c e s of room s and equipm ent

1. 7 . 2 . 1. E very th in g used fo r w ork with rad io activ e m a te r ia ls m ay be su b je c t to contam in ation . T h is inclu des s u r fa c e s of working p la ce s , w alls of fum e hoods and glove b o xes , f lo o rs and w alls of w orking ro o m s, cloth ing, equipm ent, e tc . Contam ination by ra d io activ e su b stan ce s of w orking s u r fa c e s , cloth ing , and equipm ent can be a s ig n ifica n t hazard to health and m ay a lso in te r fe re with the w ork being c a rr ie d out.

1. 7 . 2 . 2 . It is not yet p o ssib le to recom m end in tern atio n ally a c cepted p e rm is s ib le lev e ls fo r s u rfa ce contam ination o r fo r con tam ination o f cloth ing and equipm ent. H ow ever, the accep tab le lev els in a num ber o f co u n trie s given in Appendix II as exam p les m ay be used as a guide. If it is known that contam ination is perm anently fixed , m onitoring can be based , with the advice of the rad io lo g ica l health and sa fe ty o f f ic e r , on the co n sid era tio n of p e rm is s ib le e x te rn a l rad ia tio n le v e ls .

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1 . 7 . 2. 3. It i s n e c e s s a ry to c a r ry out sy s te m a tic m onitoring of contam in ation of a ll a re a s and equipm ent that have been in con tact with rad io activ e m a te r ia ls . Such m onitoring m ust be p erfo rm ed at le a s t when the work has been com pleted and, i f n e c e s s a ry , a lso s e v e r a l tim e s during the w ork.

1. 7 . 2 . 4 . M onitoring should be p erfo rm ed both with the help of counting in stru m en ts and by sm e a r te s ts . G e ig e r-M u lle r cou n ters a re su itab le fo r exam ining the s m e a r sam p les taken; the p re sen ce of alpha e m it te r s m ay m ake an alpha s c in tilla t io n m onitor o r equ iv alen t d ev ice d e s ira b le .

1. 7. 2 . 5 . When alpha o r so ft b e ta e m itte rs are u sed , the w alls o f b e a k e rs , b o tt le s , p ip e tte s , e tc . m ay ab so rb m o st of the ra d ia tion , so that m onitoring only the ou tside o f such co n ta in ers m ay be in su ffic ien t. The p re se n ce of lo w -en erg y rad iatio n c a lls fo r s p e c ia l m onitoring m ethods and equipm ent fo r s u r fa c e m onitoring .

1. 7 . 2 . 6 . E x p e rim e n ta l an im als and th e ir e x c re ta and the p re m is e s , c a g e s , e t c . , w here they a re kept should be m onitored .

1. 7 . 3 . M onitoring of a ir contam ination

1. 7 . 3 . 1 . In c a s e s w here rad io activ e g a s e s , a e ro s o ls , pow ders o r dusts a re handled o r produced, the a ir m ust be m onitored fo r contam in ation .

1. 7. 3 . 2 . A re lia b le sy stem of m onitoring the a i r a f te r filte r in g , b efo re re le a s in g it into outside p la c e s , m ust be em ployed in c a s e s w here the activ ity re le a s e d m ight exceed the le v e ls s e t by the co m petent au thority fo r such outside p la c e s .

1 . 7 . 3. 3. F o r m onitoring a e ro s o ls , the a irb o rn e su b stan ces a re deposited by e le c tr o s ta t ic p rec ip ita tio n , im p a cto rs o r filtra tio n .

1 . 7 . 3. 4. Som e rad io activ e g a ses can only be m onitored a fte r co lle c tio n by c h e m ica l o r o th er m ean s.

1. 7 . 3 . 5 . It w ill often be d e s ira b le to identify the rad io activ e co n ta m ination by ra d io ch e m ica l a n a ly sis o r p h y sica l m ean s.

1 . 7 . 4 . M onitoring of w ater contam ination

1 . 7 . 4 . 1 . S im ple m onitoring m ethods (e . g. dipping a G e ig e r-M u lle r cou n ter o r s c in tilla t io n cou nter into the w ater) w ill prove u n s a t is facto ry in many c a s e s and a m ore e lab o ra te p ro ced u re fo r m o n ito rin g w ill then have to be used .

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1. 7 . 4 . 2 . A re lia b le a s s e s s m e n t of the contam ination o f w ater to be re le a se d to public d rain s o r sew e rs in acco rd an ce with 8 . 3 . 2 . below is n e c e s s a ry . Sam pling may prove n e c e s s a ry , in which ca se the rad io activ e su b stan ce s d isso lved m ay need to be con cen trated ( e . g . by ion exchange o r evaporation) b efo re activ ity m e a s u re m ents can be c a r r ie d out.

1 . 7 . 5 . M onitoring of sk in and clothing

1. 7. 5 . 1 . Hands, cloth ing and shoes should alw ays be m onitored when w orking with un sealed s o u rc e s . No p erso n should leav e the w orking p lace (room ) without checking fo r contam ination .

1. 7 . 5 . 2 . M onitoring fo r contam ination of the sk in and clothing should be p erfo rm ed by ap p rop riate m ean s. A G e ig e r-M iille r cou n ter m ay be su ffic ien t in many c a s e s . W hen alpha con tam in ation m ay o ccu r independently o f beta and gam m a rad iatio n , an a lp h a -s e le c tiv e m onitor should a lso be provided.

1 . 7 . 5. 3. A num ber of cu rre n tly used stand ard s fo r p e rm is s ib le le v e ls o f sk in and clothing contam ination a re given in Appendix II.

1 . 8 . RECO RD S

1 . 8 . 1 . P e rs o n a l h isto ry

1. 8 . 1 . 1 . A health re c o rd , in a form to be approved by the com petent au thority , should be kept fo r ev ery w o rk er exposed to ionizing ra d iation . Such re c o rd s should contain re lev an t data and in form ation on:

(a) The natu re of the work involving rad iatio n and the type of rad ia tio n involved;

(b) The extent to which the individual has been , o r m ay have b een , exposed to rad ia tio n , as d eterm ined by v ario u s individual o r c o lle c tiv e m onitoring m ethods. In p a r t ic u la r , the accum ulated dose of rad ia tio n re ce iv e d should be re g u la rly com puted; and

(c ) Any r e s u lts av ailab le from m ed ica l exam in atio n s.

1. 8 . 1. 2 . T h e se re c o rd s should be in such a fo rm that they can be used fo r s ta t is t ic s on an in te rn a l, national o r in tern a tio n a l b a s is .

1 . 8 . 2 . A re a m onitoring re s u lts

1 . 8 . 2 . 1. R e co rd s should be kept of the re s u lts of a re a m onitoring and o f s ig n ifica n t events con cern in g rad iatio n p ro tectio n . It is su ggested that a w o rk in g -a re a log-book be kept. Such re c o rd s w ill u su ally co n stitu te the only so u rce of the data needed in in v e stig a tio n s.

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2 . SE A L E D SOURCES

2 . 1 . CHOICE AND D ESIGN O F SEA LED SO URCES

2 . 1 . 1 . A so u rce used to produce a rad iation field m ust be sealed in a su itab le co n ta in er o r p rep ared in a form providing equivalent p ro te ctio n ag a in st m e ch an ica l d isru ption . In som e c a s e s p ro tectio n ag a in st heat and c o rro s io n e ffe c ts m ay be req u ired in addition. The c h a r a c te r is t ic s s e t out in 2 . 1 . 1. 1. - 2 . 1 . 1 . 3. below a re d e s ira b le , to the extent that they a re co n siste n t with the w ork being c a r r ie d out.

2. 1. 1. 1. The a ctiv ity of the so u rce should be as low as p o ss ib le .

2 . 1. 1. 2 . The energy o r p enetrating power of the em itted rad iation should not be g re a te r than that n e c e s s a ry to acco m p lish the task with a m inim um to ta l exp o su re .

2. 1. 1 . 3 . If p o ss ib le , the rad io activ e m a te r ia l in the so u rce should be o f low to x ic ity and in such ch e m ica l and p h y sica l form as to m in im ize d isp e rsio n , and intake and re ten tio n in the body, in the event o f the co n ta in e r being b roken .

2 . 1 . 2 . Sealed so u rce s should be m arked to p erm it individual id en tifica tio n , and to fa c ili ta te d eterm in ation of the nature and quantity o f the rad io activ ity p re se n t, without undue exp o su re of the w o rk er.

2 . 1 . 3 . Sealed s o u rc e s o r the co n ta in ers of so u rce s should be re g u la r ly exam ined fo r contam in ation o r leakage (s m e a r te s ts and/or e le c tr o s ta t ic co lle c tio n m ay be u sed ). The in te rv a l betw een exam in ations should be d eterm ined by the nature o f the so u rce .

2 . 1 . 4 . M ech an ica lly dam aged o r corrod ed s o u rc e s m ust not be used and should be p laced in sea led co n ta in e rs . They should be re p a ired only by a te ch n ica lly sk illed p erson using su itab le fa c i l i t ie s .

2 . 2 . M ETHODS OF USE O F SO URCES

2 . 2 . 1 . S o u rce s should alw ays be handled in such a way that the location is known at a ll t im e s . Inventories should be kept.

2 . 2 . 2 . If any p erso n has re a so n to b elieve that a so u rce has been lo st o r m isla id , he should notify the rad io lo g ica l health and safety o f f ic e r im m ed ia te ly . If the lo s s is confirm ed , the com petent authority should be notified without delay.

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2 . 2 . 3 . S o u rces should be handled in such a way that the rad iation dose to p erso n n el is reduced to a m inim um by such m ethods as sh ield ing , keeping them at a d istan ce and lim itin g the w orking tim e .

2 . 2 . 4 . S o u rces should be handled in such a way as to avoid hazard s to a ll p erso n n el, including those not involved in the o p era tio n s. A ttention should be paid to people in ad jacen t a r e a s , including room s above and below . A rea s su b je c t to high rad iation lev e ls should be c le a r ly m arked and, i f n e c e s s a ry , roped off.

2 . 2 . 5 . B eam s of rad ia tio n a ris in g from a p a rtia lly shielded so u rce should be c le a r ly ind icated . C are should be taken to en su re that such a beam is stopped at the m inim um p ra c t ic a l d istan ce by su itab le ab so rb in g m a te r ia l. M onitoring p ro ced u res should be planned to take into account the sharp co llim atio n of rad iatio n fie ld s w hich may o ccu r.

2 . 2 . 6 . W hen p ra c t ic a b le , sea led so u rce s should be used in en clo sed in s ta lla tio n s from which a ll p erso n s are excluded during irra d ia tio n .

2 . 2 . 7 . S o u rce s should not be touched by hand b ecau se of the p o ss ib ility of high dose r a te s . A p prop riate to o ls should be used ( e . g . long-handled, light-w eight fo rcep s with a firm g rip ). If needed, even m o re e la b o ra te m eans of p ro tectio n have to be con sid ered , such as m a s te r -s la v e m anip u lators, e tc .

2 . 2 . 8 . W ork with rad io activ e m a te r ia ls should be planned to p erm it as sh o rt an exp osu re as p o ss ib le . The extent of p ro tectio n provided by lim itin g w orking tim e can e a s ily be lo s t i f unexpected d ifficu ltie s o ccu r in the w ork, so that dummy runs should p re fe ra b ly be p erfo rm ed w henever p o ss ib le .

2 . 2 . 9 . Although work should be planned to lim it exposure tim e toa sa fe fig u re , if su ffic ien t sh ielding cannot be provided and the tim e of exp o su re has to be co n tro lled , th is should be c a rr ie d out in a s y s te m a tic way, p re fe ra b ly with tim e-k eep in g and w arning s e r v ic e s outside the co n tro l o f the actu a l w o rk er.

2 . 3 . SHIELDING

2 . 3 . 1 . Adequate sh ield ing should be provided.

2 . 3 . 2 . F o r b eta ra y s the ey es , face and bcdy can be p ro tected by tra n sp a ren t p la tes of m od erate th ick n e ss .

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2 . 3 . 3 . F o r gam m a ra y s the head and body m ay be p ro tected by sh ield ing s c re e n s adequate fo r the so u rce being used .

2 . 3 . 4 . In addition to sh ield ing fo r d ire c t rad ia tio n , sh ield ing m ay be n e c e s s a ry to give adequate p ro tectio n again st the b a ck sca tte r in g fro m the flo o r and ce ilin g (proper c a r e should be taken against d ir e c t rad ia tio n through the supporting s tru c tu r e ) . A ir s c a t te r m ay a lso be s ig n ifica n t in som e c a s e s .

2 . 3 . 5 . B r ic k s used fo r sh ield ing so u rce s should ov erlap to prevent p en etra tion of rad ia tio n through the jo in ts .

2 . 3 . 6 . Shield ing should, as fa r as p o ss ib le , be n e a r the so u rce .

2 . 3 . 7 . As th e re a re many p o ss ib ilit ie s fo r e r r o r in sh ield ing ca lcu la tio n , the adequacy of sh ield ing should alw ays be tested by m e asu rem en t.

2 . 4 . SP E C IA L U SES OF SE A L E D SO URCES

2 . 4 . 1 . L a rg e so u rce s and te le th erap y in sta lla tio n s in m ed ica l d ep artm ents

2 . 4 . 1. 1. H igh -in ten sity ionizing rad ia tio n s should be used only within e n c lo su re s s e t ap art fo r the purpose and providing adequate p ro tectio n under a ll o p eratin g conditions against the u sefu l beam , leakage and s ca tte re d rad ia tio n s , fo r a ll p erso n s outside the e n c lo s u r e s .

2. 4 . 1 . 2 . Sh ield ing should be adequate to p ro tect p erso n s in n eighbouring ro om s and on ad jacen t f lo o rs . The sh ielding m a te r ia l should not lo se its e ffe c tiv e n e ss through creep in g o r sagging.

2 . 4 . 1 . 3 . In the c a s e of in s ta lla tio n s fo r te le th erap y , the co n tro ls should be in a sep a ra te room .

2 . 4 . 1 . 4 . E ffe c tiv e in te r lo ck s should be provided to prevent any p erso n from en terin g a rad ia tio n room during irra d ia tio n .

2. 4 . 1. 5 . Su itab le m eans of ex it should be provided so that any p erso n who m ight be shut in can leav e the en clo su re without delay.

2. 4 . 1 . 6 . T e le th e ra p y apparatus should be con stru cted on the " f a i l sa fe " p rin c ip le , i . e . so that the beam is au to m atica lly cut o ff in ca s e of any ir re g u la r ity , fo r in sta n ce , the opening of d oors during irra d ia tio n ; the activ atin g fo rce should only be capable of being in itia ted again from the co n tro l panel.

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2 . 4 . 1. 7. L ight o r audible sig n als o r both a re recom m ended insid e and outside e n c lo s u re s , and a lso in the v ic in ity of in s ta lla tio n s , to provide w arning b efo re and during irra d ia tio n .

2 . 4 . 1 . 8 . A rad iatio n m onitor should be provided in the te le th erap y room to give a w arning sign al to an occupant i f the dose ra te exceed s a p r e - s e t le v e l.

2 . 4 . 2 . S m all so u rce s fo r contact and in te r s t it ia l therapy in m ed ica l d ep artm ents

2. 4 . 2 . 1 . R ad io activ e so u rce s fo r contact o r in te r s t it ia l therapy m ust be en clo sed in a tight m e ta llic en clo su re preventing p o ssib le co n ta m ination under n orm al u sage.

2 . 4 . 2 . 2 . A sp e c ia l room should be provided fo r the "m a k e-u p " of s o u rc e s o r a p p lica to rs , a c c e s s to th is room being re s tr ic te d to authorized p erso n n el.

2 . 4 . 2 . 3 . Handling of so u rce s in th is room m ust not inadverten tly expose people in ad jacen t room s and/or in room s above o r below to rad iatio n .

2 . 4 . 2 . 4 . Adequate sh ielding and handling equipm ent m ust be used in the "m a k e -u p "o f so u rce s o r a p p lica to rs in o rd e r to m in im ize the rad ia tio n exp o su re to the p erso n n n el.

2 . 4 . 2 . 5 . P e r io d ic in v en to ries should be c a r r ie d out and p rop er re c o rd s kept, including a re co rd of so u rce s in u se .

2. 4 . 2 . 6 . W hen so u rce s o r a p p lica to rs a re used on a patient, su ffic ie n t p ro te ctiv e m e a su re s should be taken to m in im ize the rad ia tio n h azard s to o th er patients o r p erso n n el in ad jacen t a re a s o r in ro om s above o r below . M ovable s c re e n s can be used fo r p ro te ctio n .

2 . 4 . 2 . 7. The fa ct that a patient is undergoing tre a tm e n t by ra d io activ e su b sta n ce s , and the p recau tions req u ired , should be c le a r ly ind icated to a ll con cern ed in a m anner approved by the re sp o n sib le au th ority . P a tie n ts should be located during trea tm en t in sp e c ia l ro om s o r at le a s t at a s p e c ia l p lace so as to avoid irra d ia tio n of oth er p e rso n s as m uch as p o ss ib le . A n otice should in d icate the p re se n ce of rad io activ e s o u rc e s to the p erso n n el.

2 . 4 . 2 . 8 . The m ovem ents of the patient undergoing trea tm en t should be r e s tr ic te d acco rd in g to the so u rce s used .

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2 . 4 . 2 . 9 . A fter tre a tm e n t the used so u rce m ust be in sp ected c a r e fu lly by the p erso n in ch arge of the so u rce to a s c e r ta in that no contam in ation could have o ccu rre d .

2 . 4 . 3 . In d u stria l gam m a radiography2. 4 . 3 . 1 . Adequate sh ield ing should be provided by the co n ta in er in which the so u rce is kept when not in u se . H ig h -activ ity so u rce s (e .g . th o se in e x c e s s of 1 C i co b a lt-6 0 o r 5 C i c a e s iu m -1 3 7 ) which a re in frequent use should have co n ta in e rs from which the so u rce can be withdraw n and retu rned m ech an ica lly , e le c tr ic a lly o r p n eu m atica lly .2 . 4 . 3 . 2 . W h erev er reaso n ab ly p ra c t ic a b le , gam m a radiography should be c a r r ie d out insid e a w alled e n clo su re se t ap art fo r the purpose and w hich provides adequate sh ield ing when the so u rce is exposed . The use of so u rce s should not inad v erten tly expose p erson s in ad jacen t a re a s and/or in ro om s above o r below . If the en c lo s u re is open-topped o r has only a thinly shielded ro o f, the p o ss ib ility of rad iatio n being sc a tte re d b ack down into w orking a re a s m u st be co n sid ered . To safeg u ard m aintenance w o rk e rs and o th e rs who m ay need a c c e s s to ro o fs above gam m a rad iography ro om s w here such ro o fs do not provide adequate sh ield ing:

(a) W arning n o tices should be provided at a c c e s s points;(b) A ro o f w arning light should be op erated during actu a l

exp o su re ; and(c) A "p e rm it- to -w o rk " sy stem should be in trod u ced .

2. 4 . 3 . 3 . W here it is not reaso n ab ly p ra c tica b le to c a r ry out the rad iography insid e a w alled e n c lo su re , the radiography should be iso la te d from oth er w ork and a ll excep t authorized p erson s excluded from a su itab ly co n tro lled en clo su re o r a re a around the w ork. The co n tro lled a r e a should be c le a r ly m arked with e a s ily reco g n izab le s ig n s 5 . It should be m ade in a c c e s s ib le to unauthorized p erso n n el.

2 . 4 . 3 . 4 . L ight o r audible s ig n a ls o r both should be provided to give adequate w arning when the so u rce is about to be exposed and during irra d ia tio n . E v en w here the s ig n als have to be sw itched on by hand, the use should be con sid ered of a w arning sig n al which o p era tes au to m atica lly when the background rad ia tio n in c r e a s e s with the exp o su re of the beam . W here ligh ts a re used , th e re should be at le a s t two lam ps in p a ra lle l .

2 . 4 . 3 . 5 . The rad io g rap h ic se t-u p should be com pleted b efo re s ta r tin g the irra d ia tio n .

5 For the use o f the basic ionizing radiation symbol, see ISO Recommendation No. ISO/R 361-1963(E ).

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2 . 4 . 3 . 6 . F o r rad iography which re q u ire s the rem ov al of the sea led so u rce fro m its sh ield ing co n ta in er, a c le a r ly id en tifiab le dummy cap su le should be used during any p re lim in a ry ad ju stm ent that may be n e c e s s a ry .2 . 4 . 3 . 7. If the sea led so u rce needs to be handled outside the sh ield ing co n ta in e r, th is should be done au tom atica lly o r by rem ote handling d ev ice s , so that a ll p erso n n el con cern ed with the op eration a re adequately p ro tected .

2 . 4 . 3 . 8 . B e ca u se many gam m a radiography co n ta in ers a re op erated m anually , it is in m o st c a s e s not p o ss ib le to in te rlo ck the m ovem ent o f the so u rce o r the exp o su re of the beam with the d oors to the en c lo s u re . The d oors should th e re fo re be locked when le ft unattended. R ad iation d etection in stru m en ts m ust be av a ilab le fo r m onitoring the irra d ia tio n a re a and fo r v erify in g that the rad iograp hic so u rce has been c o r r e c t ly retu rn ed to its sh ielding co n ta in er at the end of the rad iog rap h ic e x p o su re s .2. 4 . 3 . 9 . F o r the p ro tectio n of p erson s who m ay be shut insid e a w alled en clo su re th ere m ust be e ith e r :

(a) A quick m eans of exit;(b) M eans whe-reby the so u rce can be shielded prom ptly; o r(c) Shielding behind which the p erso n can stand until he is

re le a s e d .W here n e c e s s a ry , m eans of com m unication should be provided to enable a p erso n shut in the en clo su re to sum m on help .2 . 4 . 3 . 1 0 . W hen an in d u stria l gam m a radiography so u rce is used, away from the p re m is e s of norm al u se , n o tices co n sistin g of d iagram s and/or photographs with d im ensions and identifying fe a tu res of the rad io activ e so u rce , and the step s to be taken by any p erso n finding such a so u rce , should be p rep ared . T h ese n o tices should be d is played at the a r e a w h ere the so u rce is being used until its rem ov al from that a re a has been v e rifie d .

2 . 4 . 4 . T h ick n e ss gauges, s ta tic e lim in a to rs and s im ila r d ev ices u sing sea led so u rce s

2 . 4 . 4 . 1 . R ad io activ e m a te r ia ls used fo r th ick n e ss gauges, s ta tic e lim in a to rs and s im ila r d ev ices should be in the form of sea led s o u rc e s conform ing to the g e n era l p ro v ision s fo r sea led s o u rc e s .

2. 4 . 4 . 2 . The n o rm ally unshielded portion of a sea led so u rce should be p ro tected again st m ech an ica l dam age and inadverten t co n tact. S o u rce s m ust be provided with a co v e r p late , sh u tter o r sh ield that can be re a d ily secu re d and which m ust be used when the so u rce is not in op eration so that the u sefu l beam is e ffe c tiv e ly in tercep ted .

2 0


2 . 4 . 4 . 3 . W h e re v e r p o ss ib le , such d ev ices should be in sta lled o r sh ielded so a s to en su re that the le v e ls of irra d ia tio n of a l l p e rso n s , including those in sta llin g o r m aintaining the sea led so u rce o r any m ach in ery o r plant in c lo s e p roxim ity to it , should be in conform ity with the p erm itted d oses to the g en era l public esta b lish e d by the com petent authority (so avoiding the need fo r p erso n n el m onitoring p ro ced u res and sp e c ia l m ed ica l exam in ation s).

2 . 4 . 4 . 4 . Such d ev ices should be conspicuously and perm anently m arked so as to w arn p erso n n el o f the p re sen ce of rad io activ e m a te r ia l and the need to avoid u n n ecessary exp o su re .

2 . 4 . 4 . 5 . So u rces m ust be re g u la rly exam ined by a com petent p erso n .

2 . 4 . 4 . 6 . In c a s e of dam age to the so u rce , the ra d io lo g ica l health and sa fe ty o ff ic e r or o ther d esignated p erson s should be notified at once.

3. U N SEA LED SOURCES

3 . 1 . G E N E R A L O PERA TIO N S WITH U N SEA LED SO URCES

3 . 1 . 1 . The p ro v isio n s o f 2 . 2 . and 2 . 3 . above re la tin g to sealed so u rce s a lso apply to un sealed so u rc e s . W ith re g a rd to m arking , the co rresp o n d in g in d ication s should be put on the a sso c ia te d co n ta in e r of an u n sealed s o u rce .

3 . 1 . 2 . A ll o p eration s should be planned to lim it the sp read o r d is p e rs a l o f rad io activ e m a te r ia l. To th is end a ll u n n ece ssa ry m o vem ent of p erso n s o r m a te r ia ls should be avoided.'

3 . 1 . 3 . A rea s in which rad io activ e work is c a r r ie d out should be d esignated , m arked and m onitored . At the bound aries of such activ e a re a s m onitoring and co n tro l m e a su re s should be s e t up i f so r e quired by the lev e ls of rad io activ ity p re sen t. In la rg e e sta b lish m e n ts such ch eck points should be estab lish ed not only betw een a re a s subje c t to rad io activ e contam in ation and those not, but a lso in re s p e c t of d iffe ren t types of w ork w ithin an active a r e a . In th is way an a cc id e n ta l escap e of rad io activ e m a te r ia l can be lim ited to a r e s tr ic te d a re a and d ifficu lt and expensive d econtam ination can be avoided.

3 . 1 . 4 . Equipm ent, g la ssw a re , to o ls and clean ing equipm ent fo r use in any p a r t ic u la r activ e a re a should not be used fo r w ork in in activ e a re a s and should be su itab ly m ark ed . S p e c ia l co n sid era tio n should be given to avoiding contam ination o f m a jo r ite m s of equipm ent w hich m ight need to be t ra n s fe r r e d for econ om ic re a s o n s .

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3 . 1 . 5 . Equipm ent should not n e ed less ly be brought from in activ e a re a s to activ e o n es . C ontam inated equipm ent, e t c . , should not be re le a se d from a con tro lled a re a fo r re p a ir until the lev el of activ ity has been reduced to sa fe lim its as se t by the ra d io lo g ica l health and sa fe ty o f f ic e r .

3 . 1 . 6 . The u se of new techniqu es should f i r s t be approved by the re sp o n sib le p erso n and be trie d out with in activ e m a te r ia ls o r with m a te r ia l of low a c tiv ity .

3 . 1 . 7 . P lanning should allow adequate tim e fo r the op eration s re q u ired .

3 . 1 . 8 . P re ca u tio n s to be taken fo r handling un sealed so u rce s d epend on the d eg ree of rad io to x ic ity , on the quantity of the su bstance being used and on the nature of the o p eration . C ontam ination hazard s such a s r is k s from e x te rn a l contam ination , sk in p en etration , in g e s tion o r inhalation should be con sid ered in addition to the usu al ra d iation h azard s of sea led so u rc e s . The p erso n in ch arge of the la b o ra to ry , in con su ltatio n with the ra d io lo g ica l health and safe ty o f fic e r , should issu e w orking in stru ctio n s taking into account working co n ditions and accep tab le r is k s .

3 . 1 . 9 . A rad ionuclide can be c la ss if ie d in one of the four follow ing groups of rad io to x icity p er unit activ ity :

(a) V ery high rad io tox icity ;(b) High rad io tox icity ;(c) M oderate rad io to x ic ity ; and(d) Low rad io to x ic ity .

3 . 1 . 10. In dealing with unsealed rad io activ e m a te r ia ls , s p e c ia l atten tion has to be paid to in tern a l rad ia tio n h a z a rd s . The extent of the p recau tio n s to be taken w ill depend upon such fa c to rs as the natu re of the op eration , the to ta l activ ity , the s p e c if ic a c tiv ity , the rad io to x ic ity , the ch e m ica l com position and to x ic ity in excep tion al c a s e s , and o th er ch e m ica l and p h y sica l p ro p e rtie s of the ra d io nu clid es o r rad io activ e com pounds. A c la s s if ic a tio n of rad ionu clid es acco rd in g to re la tiv e to x ic ity p e r unit activ ity is given in T ab le I 6. T h is c la s s if ic a t io n is b ased p rim a rily on the inhalation r is k . It

6 In the case o f some radionuclides the classification may need to be revised in the light of experience.

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s e r v e s in tu rn as the b a s is fo r the stand ard s of d esign of la b o ra to r i e s re q u ired fo r a broad sp read of le v e ls of u n sea led rad ion u clid es handled in d ifferen t w ays, as shown in T ab le II. (It should be noted that even when the in te rn a l rad ia tio n r is k s a re s m a ll, th e re may s t i l l be e x te rn a l rad ia tio n r is k s in handling un sealed rad io activ e m a te r ia ls , in w hich c a se the re lev an t recom m end ations fo r sealed so u rce s w ill a p p ly .)

3 . 1 . 1 1 . The v ario u s types of working p lace o r la b o r a to ry 1 req u ired fo r using a broad sp read of le v e ls of unsealed rad io iso to p es handled in d ifferen t ways a re indicated in T ab le II.

3 . 1 . 1 2 . M odifying fa c to rs may be applied to the qu an tities in d icated in the la s t th re e colum ns of T ab le II, acco rd in g to the com p lex ity of the p ro ced u res to be follow ed. The follow ing fa c to rs a re su ggested , but due re g a rd should be paid to the c ircu m sta n ce s affectin g individual c a s e s .

P ro ce d u re M odifying fa c to r

Sto rag e (s to ck so lu tions) X 100V ery sim p le wet o p eration s X 10N orm al c h e m ica l o p eration s X 1Com plex w et op eration s with r is k of sp ills X 0 .1Sim ple dry op eration s X 0 .1D ry and dusty op eration s X 0 . 0 1

3 . 1 . 1 3 . As is the c a s e fo r sea led so u rce s , u n sealed so u rce s should be handled with equipm ent providing p ro tectio n again st e x te rn a l rad iatio n .

3 . 1 . 1 4 . M anipulations should be c a r r ie d out o v e r a su itab le drip tra y , o r with som e form o f double co n ta in er w hich w ill m in im ize the e ffe c ts o f b reak ag e s o r s p i l ls . It is a lso good p ra c t ic e to co v er the w orking s u r fa c e s with ab so rb en t m a te r ia l to soak up m inor s p ills . The ab so rb en t m a te r ia l should be changed when unsuitable fo r fu rth e r use and be tre a te d as rad io activ e w aste .

3 . 1 . 1 5 . Shielding should be provided as n e ar the co n ta in e r of the rad io activ e su b stan ce as p o ss ib le .

3 . 1 . 16. Handling to o ls and equipm ent used should be p laced in non- porous tra y s and pans on ab so rb en t d isposable p ap er which should be

7 See also: ISO Recommendation, Fundamental Principles for Protection in the Design and Construction of Installations for Work on Unsealed Radioactive M aterials, No. ISO/R 1710-1970 (E).

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T A B L E I. RADIONUCLIDES C L A SSIFIE D ACCORDING TO R E L A T IV E R A D IO TO XIC ITY P E R UNIT A C T IV IT Y

Group 1 : very high radiotoxicity

210pb 226 Ra 227 Th 231 Pa 233U 238Pu 241 Pu “ Am 244Cm 249C fJlOpo 228 Ra 228 Th «°U 234U 239Pu 242Pu 242Cm 245Cm 250Cf223Ra 227 Ac 230 Th 232U 237np “ “Pu 24IAm “ ’Cm **C m 25JC f

Group 2 : high toxicity

22 Na 56Co 95 Zr12S„.So 13‘l

144Ce 1S1Hf 2°7«.Bi

228Ac56 Cl 60Co 10SRU 127T e m

133̂ 152Eu(13yr) 2ioBi 230Pa

45 Ca 89Sr 1I0Agm 129T e m I34Cs 154Eu 182Ta 2llAt 234 Th

46 Sc 90Sr 115 C d m 124, 137 Cs 160Tb 192Ir 212Pb 236u“ ton 5iY lI4Inm 12Sj 14°Ba 170Tm 204~,T1

224Ra

249 .Bk

124 SbGroup 3 : moderate toxicity

7Be 48Sc 65Zn 91Sr103_

Ru i2STem 140La 153 Gd 187 w 158 Au

14 C 48 y 69Znm 90y IOSru 127 Te 141Ce 159 Gd l83Re 199 Au18 p Cr 72Ga 92 y 105 Rh 129Te I43Ce 165 Dy 18sRe 197 Hg24 Na 52 Mn 73As 93 Y Pd 131 Xem 142 Pr '“ Dy ,,s Re I97Hg'38 Cl 56 Mn 74As 57 Zr 109Pd >32Te ,43Pr 166Ho 185 Os 203Hg31 Si 52Fe 76 As 93Nbm 105 Ag 130 j l47Nd 169 Er 191Os 200 rj-j

32p 55Fe 77As 95 Nb uiAg 132 j 149Nd 171 Er 1930s 201

59Fe 75Se 99 Mo 109Cd l»i 147Pm 171Tm 190 & 202T1

41a 57Co 82Br 96 T c 115Cd 135j 149 Pm 175Yb 194 It 203Pb42k 58Co 85Kr™ 97 T c m 115Inm 135Xe 151Sm 177Lu 191 Pt 206gi43r 63Ni 87Kr 97 T c u3Sn 131Cs 153Sm 181W 193Pt 212Bi47Ca 65Ni 86Rb 99 T c 125Sn 136Cs 152E u (9 .2 h ) 197Pt 220Rn

47Sc «Cu 85Sr 97 RU 122Sb 131Ba 15sEu 1S5W 196Au 222Rn

Group 4 : low toxicity

3H 58Com 71 Ge 87 Rb «N b i°3Rhm 131X em 135Cs 191Osm 232^ 238[J

15o 59Ni 85 Kr 91 ym 96Tcm u3Inm 133Xe l47Sm ■ I93pjm N atxh N atu

37a 69 Zn 85Srm 93 zr " T c m 129j 134Csm 187Re I97pjm 235U


T A B L E I I . L IM IT A T IO N ON A C T I V I T I E S IN V A R IO U S T Y P E S O FW O R K IN G P L A C E O R L A B O R A T O R Y 3

Radiotoxicity of radionuclides

Minimumsignificant

quantity(MCi)

Type of working place or laboratory required

Type C Type B Type A

1. Very high 0 .1 10 pCi or less 10 (iCi - 10 mCi 10 m Ci or more

2. High 1 .0 100 /iCi or less 100 pCi - 100 mCi 100 mCi or more

3. Moderate 10 1 m Ci or less 1 mCi - 1 Ci 1 Ci or more

4. Low 100 10 mCi or less 10 mCi - 10 Ci 10 Ci or more

a Type C , Type B and Type A have the meanings normally used in the classification of laboratories for handling radioactive m aterials. Type C is a good quality ch em ical laboratory.Type B is a specially designed radioisotope laboratory. Type A is a specially designed laboratory for handling large activities of highly radioactive m aterials. In the case of a conventional modern ch em ical laboratory with adequate ventilation and fume hoods, as well as polished, easily cleaned, non-absorbing surfaces, e t c . , i t would be possible to increase the upper lim its o f activity for Type-C laboratories towards the lim its for Type-B laboratories for toxicity groups 3 and 4.

changed freq u en tly . P ip e tte s , s t ir r in g rods and s im ila r equipm ent should n ev er be p laced d irec tly on the bench o r ta b le .

3 . 1 . 1 7 . A fter u se , a ll v e s s e ls and tools should be s e t asid e fo r sp e c ia l atten tion when clean in g .

3 . 2 . CHOICE O F RAD IO ACTIVE M A TERIA L AND SU IT A B L E P R O C E SSE S

3 . 2 . 1 . When a ch o ice betw een s e v e r a l rad ion u clid es o f varying to x ic it ie s is p o ss ib le , one o f re la t iv e ly low to x ic ity should be used .

3 . 2 . 2 . M a te r ia ls of low s p e c if ic activ ity should be used i f p o ssib le

3 . 2 . 3 . The w orking m ethods should be studied and p ro ced u res adopted to avoid as fa r as p o ssib le the d is p e rs a l of rad io activ e m a te r ia l, in p a r t ic u la r through the fo rm ation of a e ro s o ls , g a s e s , vapours o r d u sts.

3 . 2 . 4 . W et o p eration s should be used in p re fe re n ce to dry on es.

3 . 2 . 5 . F re q u e n t tr a n s fe r s should be avoided.

3 . 2 . 6 . The quantity o f rad io activ e su b stan ces ch osen as n e c e s s a ry fo r a s p e c if ic purpose should alw ays be as s m a ll as p o ss ib le .

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3 . 3 . C H O IC E AND D E S IG N O F W O R K IN G P L A C E S

3 . 3 . 1 . G en era l con sid eratio n s

3. 3 . 1 . 1 . S p e c ia l co n sid eratio n should be given to the ch o ice of f ir e -p r o o f co n stru ctio n fo r the bu ild ings. A s a ru le the s e le c tio n of the s ite of p re m is e s should be such that th e re is sm a ll r is k of land slid e o r flood.

3 . 3 . 1 . 2 . The re s e rv a tio n of sp e c ia l w orking p la ces fo r the handling of rad ion u clid es is recom m end ed . T h is recom m end ation may be co n sid ered as optional fo r work with the qu an tities lis te d in the colum n headed "T y p e C " in T ab le II, but it should be com pulso ry fo r w ork with the q uantities lis te d in the colum ns headed "T y p e B " and "T y p e A ".

3 . 3 . 1 . 3 . As fa r as p o ss ib le , the activ e a re a s should be planned and u tilized in such a m an n er as to sep a ra te w idely the d ifferen t lev e ls o f ac tiv ity .

3 . 3 . 1 . 4 . The rad ionu clid e working a re a s should be m arked .

3 . 3 . 2 . F lo o r s , w alls and working su r fa ce s

3 . 3 . 2 . 1 . The f lo o rs , w alls and working s u r fa c e s should be such that they can e a s ily be kept c lean .

3 . 3 . 2 . 2 . F o r Type C working p la ce s a polyvinyl ch lorid e o r lin o le u m -co v ere d flo o r and working s u r fa c e s cov ered with nonab so rb en t m a te r ia l and with d isposab le co v e rs is an exam ple of what would be co n sid ered s a tis fa c to ry . The w orking s u r fa c e s m ust be able to support the weight of the n e c e s s a ry sh ield ing ag ain st gam m a rad ia tio n .

3 . 3. 2 . 3 . F o r Type B working p la ces the w alls and the ce ilin g s should be cov ered with a w ashable, hard , non-porous paint, the flo o r with such m a te r ia ls as linoleum , ru b b er t i le s o r polyvinyl ch lo rid e . The ju n ction o f flo o rs and w alls should be sea led and rounded off in o rd e r to fa c ilita te clean in g . C o rn e rs , c ra c k s and rough s u r fa c e s should be avoided. W hen the w ork involves gam m a e m it te r s , the flo o r and working s u r fa c e s should be able to support the w eight of the sh ield in g .

3 . 3 . 2 . 4 . Type A w orking p laces should be sp e c ia lly designed by an e x p e rt. In g e n era l, su ch la b o ra to r ie s w ill be provided with glove boxes o r o th er com p lete ly en clo sed sy s te m s .

26


3 . 3 . 2 . 5 . W alls and flo o rs should be fre e from u n n ece ssa ry ob s ta c le s and a ll u n n e ce ssa ry o b je c ts should be rem oved from the w orking s u r fa c e .

3 . 3 . 3 . Sinks

Sinks should be provided in Type B and C w orking p la c e s . In g en era l, the usu al type o f sin k, with a sm ooth white g lazed fin ish , without b le m ish e s , w ill s u ffice . It is d e s ira b le to have the sin ks connected d ire c tly to the m ain ou tlet pipe; conn ections to open channels should be avoided, and a lso any u n n ece ssa ry d ev ices w hich m ight accu m u la te s lim e . T ap s should be designed fo r op eration by foot, knee o r elbow , ra th e r than by hand. A su itab le w a ste -d isp o sa l sy stem as d iscu sse d in 8. 3 . 2 . should be provided.

3 . 3 . 4 . F u rn itu re

The fu rn itu re should be reduced to a m inim um and should be e a s ily w ash ab le . D u st-co lle c tin g item s su ch as d ra w e rs , sh e lv es and hanging lam ps should be as few as p o ss ib le .

3 . 3 . 5 . Lighting

The w orking p re m is e s should be adequately lighted .

3 . 3 . 6 . V en tila tion

3. 3 . 6 . 1 . P ro v is io n fo r adequate v en tila tio n should be included in the o r ig in a l design o f the p re m is e s .

3 . 3 . 6 . 2 . R ou tes of en try and ex it fo r the v en tila tin g a i r should be c le a r ly defined under a ll conditions of u se , including open and clo sed p o sitio n s of d oors and windows and the vario u s op erating a rra n g em e n ts of the fume hoods. In sm a ll la b o ra to r ie s it may be p o ss ib le to provide the needed flow of a ir sim p ly by the exhaust sy stem of the fume hoods, but in such a c a s e s p e c ia l atten tion m ust be given to the inflow o f fre s h a ir into the la b o ra to ry under a ll conditions by such m eans as providing adequate lou v res in the doors of ro o m s.

3 . 3 . 6 . 3 . C on sid eration should be given to any need to tre a t o r f i l t e r incom ing a i r . In cold c lim a te s the problem of heating the intake a i r fo r a la rg e group of fum e hoods should not be overlooked , as th is m ay be a m a jo r p ro b lem .

27


3. 3 . 6 . 4 . The s itin g of in le t and exhaust vents should be such as to prevent any re c ir c u la tio n of exhausted a i r . The need to f i l t e r a ir exhau sted fro m working p la ce s and fum e hoods w ill depend on the natu re o f the w ork, the p o sition of the exhaust vent re la tiv e to the surrou ndings and the po ten tia l nu isance value of p a rticu la te s settling in the surrounding neighbourhood.

3 . 3 . 6 . 5 . Fu m e hoods should produce a re g u la r a ir flow without any ed d ies. The speed of the a ir flow should be such that th e re can be no e sca p e o f a i r from the fum e hood into the working p lace under ty p ica l op eratin g cond itions, including the opening of windows and d oors and the su ction o f o th er fume hoods. T h is can be checked by sm oke te s t s . It is recom m ended that the fan be placed on the e x haust sid e of any. f i l t e r in the sy s te m . The g as , w ater and e le c t r ic a l ap p lian ces should be op erated from the outside of the fume hood.The insid e o f the hood and the exhau st ducts should be as easy to c lean as p o ss ib le .

3 . 4 . P R O T E C T IV E CLO TH IN G 8

3 . 4 . 1 . P ro te c tiv e clothing app rop riate to the rad io activ e co n tam ination r is k s should be w orn by ev ery p erson in a con tro lled a re a , even i f only v e ry sm a ll qu an tities of rad io activ e m a te r ia ls a re m anipulated.

3 . 4 . 2 . In Type C w orking p la c e s 9 w o rk ers should w ear sim p le p ro te ctiv e cloth ing such as ord in ary la b o ra to ry o r su rg ic a l c o a ts .In Type A o r B w orking p la ces p ro tectiv e clothing o r d ev ices should be provided acco rd in g to the nature of the w ork. W hen w orking with e x p erim en ta l a n im a ls, cloth ing proof ag ain st teeth o r claw s m ay be d e s ira b le , and p ro tectio n of the face again st blood o r body- fluid sp lash in g s should be provided.

3 . 4 . 3 . In Type A and B w orking p la ces the p ro tectiv e cloth ing should be c le a r ly identified , fo r exam ple by a d ifferen t co lo u r. It should not in any c a s e be w orn outside the con tro lled a re a .

3 . 4 . 4 . W orking c lo th es and s tre e t c lo th es should be kept in se p a ra te cu b ic le s o r changing ro o m s. When changing from one to the o th er , c a re should be taken to avoid cro ss -co n ta m in a tio n r is k s .3 . 4 . 5 . R u b ber, polyvinyl ch lorid e e tc . g loves should be w orn when w orking with un sealed rad io activ e su b stan ces to p ro tect again st contam in ation o f the sk in .

See also: Respirators and Protective Clothing, Safety Series No. 22, IAEA, Vienna (1967).9 See T able II.

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3 . 4 . 6 . C are should be taken to avoid n eed less contam in ation of o b je c ts by handling them with p ro tectiv e g lov es, in p a r t ic u la r light sw itch es , tap s, door knobs, e tc . The gloves should be e ith e r taken o ff o r a p iece of non -contam inated m a te r ia l (p ap er), w hich should be d isposed of a fterw ard s with contam inated re s id u e s , should be in terp o sed .

3 . 4 . 7. Contam inated gloves should be washed b efo re being taken off.

3 . 4 . 8 . A method of putting on and taking off g loves without co n tam inating e ith e r the sk in o r the insid e of the g loves should be used .T h is p ro ced u re is such that the insid e of the glove is not touched by the ou tsid e, nor is any p art of the outside allow ed to com e in con tact with the b a re sk in . It is d e s ira b le to u se g loves of which the insid e and outside a re d istin g u ish able .

3 . 5 . PER SO N A L P R O T E C T IV E M EA SU RES

3 . 5 . 1 . No u n sealed rad io activ e so u rce s should be m anipulated with the unprotected hand.

3 . 5 . 2 . M outh-operated equipm ent, e . g . p ip ettes, m ust not be used o r even be p re sen t in any rad io iso top e la b o ra to ry .

3 . 5 . 3 . S p e cia l p recau tio n s should be taken to avoid punctures o r cu ts , e sp e c ia lly when m anipulating rad ion u clid es of high to x ic ity .

3 . 5 . 4 . Anyone who has an open sk in wound below the w ris t (p ro tected by a bandage o r not) should not w ork with rad ion u clid es without m e d ica l approval.

3 . 5 . 5 . The u se o f co n ta in e rs , g la ssw a re , e tc . having sh arp edges that could cut the hand should be avoided.

3 . 5 . 6 . C are should be taken when w orking with contam inated an im als to avoid b ite s o r s c r a tc h e s .

3 . 5 . 7. G lass-b lo w in g by mouth should be avoided in p la ces w here un sealed rad io activ e su b stan ce s a re u tilized . G lass-b lo w in g , w elding, b raz in g , so ld erin g , e tc . should n ev er be p erm itted on contam inated equipm ent u n less it is done in sp e c ia lly v en tila ted fa c i l i t ie s , and u n less sp e c ia l techniqu es a re used to p revent the inhalation of ra d io activ e dust and fu m es.

2 9


3 . 5 . 8 . Only s e lf-a d h e s iv e lab e ls should be used in co n tro lled a r e a s . L a b e ls that need to be w etted should be avoided.

3 . 5 . 9 . The follow ing should not be introduced o r used in working p la ce s containing unsealed so u rce s :

(a) Food o r b ev era g e s (w here n e c e s s a ry , drinking fountains should be provided in the v icin ity );

(b) Sm oking item s o r snuff;(c ) Handbags;(d) L ip s tick s and o th er co sm e tics o r d ev ices used to apply them ;(e) H an d kerch iefs, o th er than those re fe r re d to in 3 . 5 . 10.

below ; and(f) U ten sils fo r eatin g o r drinking.

3 . 5 . 10 . D isp o sab le p aper tow els and p ap er hand kerch iefs o r the equivalent should be provided fo r the w o rk e rs . S p e c ia l co n ta in ers should be p laced in the working p la ce s into which th e se tow els and han d k erch iefs should be thrown a fte r u se . T h ese should be trea ted as rad io activ e w aste .

3 . 5 . 1 1 . Hands should be washed thoroughly b efo re leav ing a con tro lle d a re a (s p e c ia l atten tion should be given to the n a ils , in betw een fin g e rs and the o u ter edges of the hands).

3 . 5 . 12. Show ers should be taken when recom m end ed by the ra d io lo g ica l health and sa fe ty o f f ic e r . M onitoring o f hands, sh oes and s t r e e t clo th ing , i f w orn at w ork, may a lso be n e c e s s a ry b efo re leav in g a co n tro lled a re a .

3 . 6 . CO N TRO L O F AIR CONTAMINATION

3 . 6 . 1. R ad io activ e contam ination of the a ir of the working p la ces should be reduced as is read ily ach iev ab le . AU op eration s lik e ly to produce rad io activ e contam ination o f the a ir through the p rodu ction o f a e ro s o ls (in p a r t ic u la r the heating o f rad io activ e so lu tio n s), sm oke o r vapours should be done in an a irtig h t e n c lo su re kept below a tm o sp h eric p re s s u re (glove box) o r in a fum e hood.

3 . 6 . 2 . The aim should be to im prove c o lle c tiv e p ro tectio n by the p ro v isio n and op eration o f safe w orking p la ce s and by sa fe m ethods of w ork, and so avoid r e s o r t to individual p ro tectio n by the use of r e s p ir a to r s , co m p re sse d a ir m ask s, w hole-body en clo sin g su its ,

30


e tc . Conditions w hich re q u ire extended u se of r e s p ir a to r s should not be to le ra te d .

3 . 6 . 3 . When the contam ination lev e l cannot be m aintained below the le v e ls s e t by the ra d io lo g ica l health and sa fe ty o f f ic e r , individual p ro te ctio n again st contam in ation m ust be fu rnished to the w o rk e rs . The f i r s t ch o ice of p e rso n a l re s p ir a to ry p ro tectio n should be supplied- a i r equipm ent such as an a ir - l in e hood o r p o sitiv e p re s s u re m ask . W here th e se a re un accep table (due perhaps to lim ited range and the inconv enience of a tra ilin g a ir - l in e ) , f i lte r - ty p e r e s p ir a to r s m ay be used .

3 . 6 . 4 . R e s p ira to rs should be of a form approved by a recogn izedte stin g la b o ra to ry fo r the "c lass o f s e r v ic e req u ired , and the p ra c t ic a lsa fe lim its of use should be known and o b serv ed ,

t

3 . 6 . 5 . R e s p ira to rs should be capable of standing up to the conditions of u se and should be checked and tested p e rio d ica lly .

3 . 6 . 6 . R e s p ira to rs should be individually fitted and tested fo r adequacy of f it .

3 . 6 . 7. U s e rs of r e s p ir a to r s m ust accu stom th e m se lv es to the d is c ip lin e n e c e s s a ry in th e ir u se , o th erw ise harm is lik e ly to be done by in trod u cing contam ination under the fa c e -p ie c e .

3 . 7. SP E C IA L U SES O F U N SEA LED SO U RCES

3 . 7 . 1 . In sta lla tio n s fo r the use of rad io activ e g a ses ( e . g . radon)

3 . 7. 1 . 1 . The in s ta lla tio n should be in s p e c ia l ro om s o r p re fe ra b ly in a se p a ra te building.

3 . 7. 1 . 2 . A ll ro om s w here w ork with rad io activ e g a se s is p erfo rm ed m ust be e ffic ie n tly v en tila ted .

3 . 7 . 2 . L um inizing involving application of rad io activ e m a te r ia l

3. 7. 2 . 1 . The recom m en d ation s in 3 . 7. 2 . 2 . - 3 . 7 . 2 . 1 5 . below include e x tr a c ts from the In tern ation al L abo u r O rg an izatio n 's re levan t p ro v isio n s on ionizing ra d ia tio n s . They should prove helpful in any s im ila r type of w ork with the m o re hazardous rad io iso to p es.

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3 . 7 . 2 . 2 . Lum inizing, w hether by hand o r by m achine, should be done only in w orking p la ce s of a stand ard not low er than that provided by a Type B w orking p la c e 10.

3 . 7. 2 . 3 . The p ro v isio n s re la tin g to the co v erin g s of w a lls , flo o rs and w orking s u r fa c e s ; ven tila tin g sy s te m s ; the p rohibition of eating, drinking, sm oking, snu ff-tak ing and the use o f co s m e tic s ; sto rag e of s o u rc e s ; and tre a tm e n t of rad io activ e re s id u e s should, how ever, be th o se ap p rop riate to Type A w orking p la ces o r a high standard of Type B .

3 . 7 . 2 . 4 . G love boxes o r s im ila r equipm ent should be used w h ere v e r p ra c tica b le fo r the application o f lum inous compound.

3. 7. 2 . 5 . W here the equipm ent re fe r re d to in 3. 7. 2 . 4 . above cannot be used , additional p ro tectiv e cloth ing , including w ashable aprons and b ibs o f ru b b er o r o th er w aterp roo f m a te r ia l, should be provided and used .

3. 7 . 2 . 6 . Such additional p ro tectiv e clothing should be cleaned by a wet method and m onitored daily .

3. 7 . 2 . 7. O perations with dry lum inous compound, such as fillin g g la ss ca p illa ry tubes o r w eighing out, should only be p erfo rm ed w ithin glove boxes o r under s im ila r a rra n g em e n ts .

3. 7 . 2 . 8 . L um inized w ork aw aiting drying, o r com pleted , should not be allow ed to accu m u late on o r n ear lu m in z e rs 1 w ork b en ch es, but should be rem oved at frequent in te rv a ls to a p lace of s to rag e affording adequate p ro tectio n and v e n tila tio n 11.

3. 7. 2 . 9 . In stru m en ts fo r the application o f lum inous compound m ust not on any accou nt be put into the mouth o r brought into con tact with the sk in .

3 . 7 . 2 . 10. The u se o f b ru sh es fo r the ap p lication of lum inous co m pound should be p roh ib ited .

3 . 7 . 2 . 11. Suitable re c e p ta c le s fo r lum inous compound should be provided fo r the use of p erso n s handling such compound, and should be so co n stru cted as to lim it exp osu re to b eta and gam m a rad iation and p reven t contam ination of the hands.

3. 7 . 2 . 12. A su rvey by m eans of u ltra -v io le t light o r by a su itab le rad ia tio n m o n ito r should be c a r r ie d out at le a s t once a w eek in

“ See T able II.11 See 4 . below.

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ev ery w orking p lace in which p erso n s a re em ployed on p ro c e s s e s involving the use of lum inous compound, fo r the purpose o f d etecting a re a s of rad io activ e contam in ation . Any such a re a should be cleaned forthw ith by a wet m ethod.

3. 7 . 2 . 1 3 . L um inizing m achines should be so co n stru cted as to afford adequate p ro tectio n .

3 . 7 . 2 . 1 4 . No p e rso n should, o th erw ise than by a wet method o r w ithin a glove box;

(a) Rem ove w aste m a te r ia ls containing lum inous compound from ap p lica to rs o r o th er to o ls ;

(b) Rem ove lum inous compound from the s u rfa ce of any o th er a r t ic le o r from g la ss tubing; or

(c) C lean contam inated lum inizing m achine p a r ts .

3 . 7 . 2 . 1 5 . W aste m a te r ia l a r is in g from lum inizing should be disposed of in acco rd an ce with the recom m end ations fo r rad io activ e w aste d isp o sa l.

3 . 7 . 3 . M ed ical u se s of u n sealed so u rce s

3. 7. 3 . 1. In the m ed ica l use of un sealed rad io activ e so u rce s addition al d if ficu ltie s a r is e owing to the fa c t that rad ia tio n p ro tectio n m e a su re s m ust be ob serv ed to g eth er with the usu al c l in ic a l re g u la tions fo r la b o r a to r ie s , op eratin g th e a tre s and p a tien ts ' w ard s. F u r th e rm o re , p ro tectio n again st rad iatio n , not only of the m ed ical s ta ff but a lso of o th er p atien ts and v is ito r s , m ust be a ssu re d . On the o th er hand, the m ed ica l w ork is usu ally lim ited to the u se of a sm a ll num ber of rad ion u clid es and fo r each sin gle tre a tm e n t a c tiv it ie s of 100 m Ci a re seldom exceed ed . The purely m ed ica l p ro b lem s in the d iagn o stic and th erap eu tic use o f rad ion u clid es do not fa ll w ithin the scope of th is Code. U n sealed so u rce s should not be used u n less any re q u irem en ts se t out by com petent au th o rities fo r ro o m s, p erson n el and in stru m en ts a re m et.

3. 7. 3 . 2 . F o r d iagn o stic and t r a c e r stu d ies, la b o ra to r ie s of Type C3 a re su ffic ie n t in m ost c a s e s .

3 . 7. 3 . 3 . F o r the th erap eu tic use o f rad ion u clid es, the follow ing should be provided;

(a) L a b o ra to r ie s of Type B to p rep are the iso to p es fo r the m ed ica l tre a tm e n t;

(b) A dditional room s fo r ad m in isterin g the tre a tm e n t its e lf ; and(c) W ards fo r the p atien ts who have been tre a te d with rad io n u clid es.

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In s p e c ia l c a s e s the m odifying fa c to r fo r "C om p lex wet op eration s with r is k s of s p ills " provided fo r in 3 . 1 . 1 2 . above should be applied in re s p e c t of the w orking p laces involved.

3 . 7 . 3 . 4 . It is recom m ended that th ese ro om s should be c lo s e to g e th e r and iso la te d , i f p o ss ib le , from the o th er se c tio n s o f the h osp ita l; they should be regard ed and designated as a "co n tro lled a r e a " .

3 . 7 . 3 . 5. A patient tre a te d with rad ion u clid es m ust be reg ard ed as a so u rce o f rad ia tio n and contam ination from w hich the m ed ica l s ta ff and o th er s ta ff as w ell as the o th er p erso n s may need to be p ro tected .

3. 7 . 3 . 6 . S p e cia l attention m ust be given to the p ro p er in stru ctio n and p ro tectio n of p a tie n ts ' attendants, s in ce th e ir duties involve p a r t ic u la r r is k s of contam ination and irra d ia tio n . U n n ecessary lo ite r in g o f attendants n e a r the p atien ts ' beds should be avoided.

3. 7. 3 . 7 . The recom m end ations of 3 . 1 . above with re s p e c t to g e n era l o p eration s with unsealed so u rce s should be follow ed. Sp ecia l techniqu es in using the m ed ica l in stru m en ts req u ired , e . g . sy rin g e s , m ay be n e c e s s a ry .

3. 7 . 3 . 8 . The quantity of rad ioactiv e m a te r ia l on hand w ithin the tre a tm e n t room should be lim ited to that req u ired fo r actu a l ad m in istra tio n , s in ce th is w ill m ake it p o ssib le to re la x many o f the safety re q u irem en ts .

3. 7 . 3 . 9 . C ontam inated in stru m en ts, v e s s e ls , linen , e tc . m ust be decontam inated in acco rd an ce with 7 . 2 . below .

3. 7 . 3 . 10 . The e x c r e ta of in tern a lly tre a te d p atien ts should be tre a te d as rad io activ e w aste .

3 . 7 . 3 . 11. The m ovem ents of the patient undergoing tre a tm e n t should be r e s tr ic te d acco rd in g to the potential hazard he may re p re s e n t .

3. 7 . 4 . R ad ionuclid es in an im al exp erim en ts

3 . 7. 4 . 1. The foregoing g en era l p ro v ision s fo r w ork with unsealed s o u rc e s should be follow ed.

3. 7 . 4 . 2 . In addition, the unw arranted sp read of contam ination by an im als o r from an im al e x c re ta re q u ire s s p e c ia l co n sid era tio n in the design o f ca g e s and ro o m s.

3 . 7. 4 . 3 . E x c r e ta , body con stitu en ts from b io p sies and au top sies and an im al cad av e rs should be trea ted as rad io activ e w aste . P o s s ib le

3 4


h azard s of sp read of contam in ation through the d ecom p osition p ro c e s s should be p revented , e .g . by deep fre e z in g and the use of d is in fe cta n ts , sea led p la s tic co n ta in e rs , gypsum o r k iese lg u h r.

3 . 7 . 4 . 4 . S p e c ia l a rran g em e n ts should be made fo r the co lle c tio n of e x c r e ta and the d econtam ination o f c a g e s .

3 . 7. 4 . 5 . The rad io activ e an im als o r th e ir cag es should be m arked with la b e ls ind icating the natu re and amount of rad io iso to p es used and the tim e of a d m in istra tio n .

3. 7 . 4 . 6 . No u n contro lled exchange o f a n im a ls , in stru m en ts, ca g e s , e tc . betw een activ e and inactive la b o ra to r ie s should be allow ed.

3 . 7 . 4 . 7. P re ca u tio n s should be taken to prevent the p o ss ib ility of re ce iv in g contam inated wounds in the co u rse of handling the an im als and contam in ation from rad io activ e a e ro s o ls o r sp lash in g s produced by a n im a ls ' m ovem ents, coughing, e tc .

3 . 7 . 4 . 8 . F o r w ork with rad io activ e an im als, the m odifying fa c to r of 0 .1 provided fo r in 3 . 1 . 1 2 . above should n orm ally be applied in re s p e c t o f the w orking p la ces involved.

3. 7. 4 . 9 . The p re se n ce of v erm in as p o ten tia l v e c to rs of con tam in ation should be co n sid ered .

4 . STO RA G E O F SO URCES

4 . 1 . P L A C E OF STO RA G E

4. 1. 1. W hen not in u se , rad io activ e so u rce s should be kept in a p lace o f s to ra g e assig n ed fo r th is purpose only.

4 . 1 . 2 . The p lace of s to ra g e should be adequately shielded and p ro p erly m arked , and a qualified p erso n should be designated to be in ch arg e o f it .

4 . 1. 3 . Only authorized p erso n n el should introd u ce so u rce s into o r rem ov e them from the p lace of s to ra g e , w hich should be se cu re again st tam p erin g .

4 . 1 . 4 . The p lace of s to rag e should be in a room provided with a su itab le m eans of e x it that can be op erated from the in sid e .

35


4 . 1 . 5 . The p lace of sto rag e should be ch osen so as to m in im ize r is k from f ir e o r flooding.

4 . 1 . 6 . P la c e s of s to rag e should be insp ected re g u larly and checked fo r p o ss ib le contam in ation .

4 . 2 . CONDITIONS O F STO RAGE

4 . 2 . 1. A ll rad io activ e so u rce s should be c le a r ly lab e lled , giving in form ation on th e ir activ ity and natu re . It may be found d es ira b le to include the name of the p erson who is resp o n sib le fo r the so u rce . In the event that a num ber of so u rce s a re n orm ally in use in a fum e- hood o r o th er w orking a re a , as fo r exam ple in a n a ly tica l w ork, the m arking m ight be of a g e n era l nature to apply to the whole working a re a . Any so u rce involving hazard s g re a te r than those lis te d in the g e n era l w arning should be sp e c ia lly m arked .

4 . 2 . 2 . The co n ta in e rs fo r b e ta -em ittin g rad ionu clid es should have adequate th ick n e ss to red uce the p rim a ry rad iatio n to a sa fe le v e l. C o n sid erab le b rem sstrah lu n g m ay a r is e fro m h ig h -in ten sity so u rce s and additional sh ield ing should be provided i f n e c e s s a ry .

4 . 2 . 3 . G am m a-em ittin g and neutron so u rce s should be sto red in such a way as to lim it the rad iation exp osu re from o th er so u rce s when any one so u rce i s being handled.

4 . 2 . 4 . W hen e ith e r sea led o r unsealed so u rce s a re liab le to r e le a s e a rad io activ e gas o r vapour th e ir p lace o f sto rag e should be e ffic ie n tly vented to the open a ir by m ech an ica l m eans b efo re it is opened.

4 . 2 . 5 . S p e c ia l equipm ent should be provided fo r s to rin g unsealed so u rce s to prevent not only e x te rn a l irra d ia tio n hazard s but a lso rad io activ e contam in ation h azard s.

4 . 2 . 6 . In Type C w orking p la c e s 12 the so u rce s m ay be sto red in s p e c ia l cupboards providing adequate p ro tectio n .

4 . 2 . 7. In Type B w orking p la ces a s p e c ia l se cu re re ce p ta c le should be used w hich p rovid es adequate p ro tectio n and can be ventilated if n e c e s s a ry .

12 See Table II.

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4 . 3 . STO RA G E O PERA TIO N S

4 . 3 . 1. R e co rd s should be kept of a ll sto red rad io activ e s o u rc e s .

4 . 3 . 2 . The re c o rd s should give c le a r in form ation on the type of s o u rce , a c tiv ity , t im e s of rem o v al and re tu rn , and the name o f the p e rso n re sp o n sib le fo r the so u rce during its ab sen ce from the s to r e .

4 . 3 . 3 . In v en to ries should be taken p e rio d ica lly .

4 . 3 . 4 . The rem o v a l o f so u rce s from the s to re and the tim e fo r which they a re rem oved should be checked to provide adequate co n tro l.

4 . 3 . 5 . T h e rm a lly un stable solutions containing rad io activ e m a te r ia ls in n itr ic acid o r o th er oxid izing solutions containing even t r a c e s of o rg an ic m a te r ia l, and sta b le solutions with a lp h a -a c tiv ity in e x c e s s of 5 m C i o r b eta activ ity in e x c e s s of 50 m C i, should alw ays be s to red in vented v e s s e ls .

4 . 3 . 6 . B o ttle s and co n ta in e rs should be such as open e a s ily .

4 . 3 . 7 . Solutions having a high alpha activ ity ( in e x c e s s of 1 mCi/ml) o r so lutions having a high beta activ ity (in e x c e s s of 100 m Ci/m l) should not be s to red in th in -w alled g la ss b o ttles , s in ce irra d ia tio n m ight w eaken the g la s s . A ll g la ss v e s s e ls m ust be expected to fa il without apparent ca u se .

4 . 3 . 8 . B o ttle s containing rad io activ e liquids should be p laced in v e s s e ls la rg e enough to hold the e n tire contents of the b o ttles in ca se o f b reak ag e .

4 . 3 . 9 . S p e cia l p recau tio n s a re requ ired when opening v e s s e ls con taining rad io activ e liquids lia b le to catch f ir e , explode o r fro th .

5 . TR A N SPO RTA TIO N O F RADIO ACTIVE M A TER IA L

5 . 1 . TR A N SPO RTA TIO N WITHIN AN E STA B L ISH M E N T

5 . 1 . 1 . No m o re rad io activ e m a te r ia l should be moved than is re q u ired .

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5 . 1 . 2 . R ad io activ e m a te r ia l should be tran sp o rted in adequately sh ield ed and c lo sed co n ta in e rs . The co n ta in e rs should be so con stru cte d as to prevent acc id en ta l r e le a s e of the so u rce -m aterial in c a s e of u p set.

5 . 1 . 3 . If rad io activ e m a te r ia l in liquid o r gaseo u s fo rm , o r in powder o r o th er d isp e rs ib le so lid fo rm , is in a sh a tte ra b le co n ta in er, it should be tran sp o rted in an ou ter n o n -sh a tte ra b le co n ta in e r . In the c a s e of liquid so u rce s the co n ta in er should be provided with ab sorb in g m a te r ia l ab le to re ta in a ll the liquid in ca se of b reak ag e .

5. 1 . 4 . Su itab le m eans should be provided fo r the t r a n s fe r of the so u rce to and from the tra n sp o rt co n ta in er.

5 . 1 . 5 . The tra n sp o rt co n ta in er should be c le a r ly m arked with w arning s ig n s .

5 . 1 . 6 . C o n tain ers in tra n sit should b e a r a tran sp o rta tio n tag showing in form ation n e c e s s a ry fo r sa fe ty , such a s :

(a) N ature of the contents;(b) P h y s ic a l condition;(c) A ctiv ity in c u r ie s ;(d) D ose ra te o f rad ia tio n at the ou ter s u rfa ce of the con tain er;(e) D ose ra te of rad ia tio n at a sp ecified d istan ce ; and(f) Kind of packing (when ap p licab le).

The tra n sp o rta tio n tag should a lso c e r tify that the ou tsid es of the co n ta in er and the package are fre e from contam in ation .

5 . 1 . 7 . The tra n sp o rta tio n tag can be dispensed with only when the so u rce is in the ch arg e and under the com p lete p h y sica l co n tro l of a p e rso n who is aw are o f the nature of the rad io activ e m a te r ia l and of the rad ia tio n hazard s involved.

5 . 1 . 8 . E m e rg en cy p ro ced u res should be planned to co v e r accid en ts to rad io activ e m a te r ia l in tra n s it .

5 . 1 . 9 . Any lo s s of rad io activ e m a te r ia l during tra n sp o rt should at once be rep o rted to the rad io lo g ica l health and sa fe ty o f f ic e r .

5 . 1 . 1 0 . Suitably tra in ed w o rk ers should be in ch arge of a ll t r a n s p o rta tio n o f hazardous qu an tities of rad io activ e m a te r ia l insid e an e sta b lish m e n t.

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5 . 2 . TR A N SPO RTA TIO N OUTSID E AN E ST A B L ISH M E N T

5 . 2 . 1 . The route and method of tran sp o rt should be a sce r ta in e d in su ffic ien t d eta il to p e rm it com p lian ce with the ru le s and regu lation s e sta b lish e d by a ll a u th o rities through whose ch arg e the consignm ent w ill p a s s . W hen tra n s-sh ip m en t is involved, it should not be assum ed that a shipm ent m eeting the in itia l au th ority 1 s re q u irem en ts w ill n e c e s s a r ily m eet th o se of the subsequent a u th o rities .

5 . 2 . 2 . The re c ip ie n t should be notified about the consignm ent and re c e iv e a ll s ig n ifican t in form ation in tim e to m ake any n e c e s s a ry p re p ara tio n s fo r re ce iv in g i t . Such in form ation should at le a s t include the method of shipm ent and e stim ated tim e o f a r r iv a l . The n o tifica tio n should include any s p e c ia l s to rag e in stru ctio n s and d eta ils of sa fe opening techniqu es fo r s p e c ia l shipping co n ta in e rs .

5 . 2 . 3 . The A g e n cy 's R egulations fo r the Safe T ra n sp o rt of R ad ioa ctiv e M a te r ia ls 13 should be follow ed a s fa r a s p o ss ib le .

6 . A C C ID EN TS14

6 . 1 . ID EN TIFIC A TIO N O F ACCID EN TS

6 . 1 . 1 . Any unplanned happening which could a ffect rad ia tio n sa fety is con sid ered an accid en t fo r the purposes of th is Code.

6 . 1 . 2 . The m ost e ss e n tia l and often the m ost d ifficu lt problem in coping with a cc id en ts is the recog n ition that an accid en t has o ccu rre d .

6 . 2 . PREC A U TIO N A RY M EA SU RES

6 . 2 . 1 . A ll w ork should be c a r r ie d out acco rd in g to a p rearran g ed plan. Any d ep artu re from the plan should be follow ed by a r e a s s e s s m ent of the rad ia tio n h azard s involved.

6 . 2 . 2 . A p prop riate accid en t in stru ctio n s should be p rep ared and posted up as a n otice , and the s ta ff should thoroughly understand them .

13 Safety Series No. 6, 1973 edition.14 See also: Planning for the Handling of Radiation Accidents, Safety Series No. 32,

IAEA, Vienna (1969).

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6 . 2 . 3 . A ccid en t in stru ctio n s should avoid any rig id r e s tr ic t io n s on conditions of ap p lica tio n . A s e r io u s s itu atio n ca n develop fro m a wide v a r ie ty o f ca u se s ranging from a sim p le sp read o f rad io activ e contam ination to such natu ral cau ses o f d is a s te r as f ir e , flood o r earth q u ak e .

6 . 2 . 4 . A ll planning o f m e asu re s to be taken in ca se of accid en ts should give p r io r ity to human safety acco rd in g to need and urgency . R esp o n sib ility fo r p ro tectin g the public m ust take p re ce d e n ce .

6 . 2 . 5 . The s ta ff should be thoroughly fa m ilia r with the p osition and m ethod o f use o f the p ro tectio n and f i r s t -a id equipm ent fo r e m e r g e n c ie s . P r a c t ic e d r ills a re e s s e n tia l. Equipm ent should be checked re g u la rly to en su re that it is in good working o rd e r .

6 . 2 . 6 . The public health au th o rities , f ire s e r v ic e and o th er s e r v ic e s o r a u th o rities (gu ard s, p o lice , e t c . ) should be kept in form ed of sp e c ia l rad iatio n hazard s and of the rad ia tio n sa fe ty m e a su re s to be taken .

6 . 2 . 7. No p erso n should undertake dangerous w ork without s o m e one standing by who can a s s is t in c a s e of tro u b le .

6 . 2 . 8 . E m erg en cy fa c i l i t ie s and s ta ff should be av ailab le when work is being c a r r ie d out with unsealed so u rce s req u irin g the use of Type A o r B w orking p la c e s 15.

6 . 2 . 9 . F i r s t - a id m e a su re s in con form ity with m ed ica l advice should be a v a ila b le .

6 . 3 . ACTIONS COMMON TO A L L A CCID EN TS

6 . 3 . 1 . The co n tro l of m e asu re s fo r dealing with any accid en t should be the re sp o n s ib ility of one individual. The individual con cern ed o r h is a lte rn a te s should be c le a r ly indicated in the accid en t in stru ctio n s and should be av a ilab le to a ll con cern ed .

6 . 3 . 2 . E v e ry accid en t should be fully rep o rted . T h is rep o rt m ay have an im portant b earin g on s ta ff health and leg a l re s p o n s ib ilit ie s and may a s s is t the rad io lo g ica l health and sa fe ty o f f ic e r in m aking a d eta iled study with a view to avoiding s im ila r a cc id e n ts in the fu tu re.

15 See Table II.

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6 . 3 . 3 . In a ll a cc id en ts the d oses re ce iv e d by the p e rso n s involved m ust be estim a ted and rep orted and follow -up m e a su re s taken as n e c e s s a ry .

6 . 3 . 4 . A ll acc id en ts should be in vestig ated and ap p rop riate m e a su re s should be taken to avoid a cc id e n ts .

6 . 4 . A C CID EN TS INVOLVING RADIO ACTIVE CONTAMINATION

6 . 4 . 1 . R ad io activ e m a te r ia l may be a cc id e n ta lly re le a s e d by a sp ill, by a fa ilu re of equipm ent o r by rupture o f a sea led s o u rce . The actio n s which may be ap p rop riate to prevent w idespread contam ination and exp osu re of p erso n n el in such a c a s e , and the o rd e r in which such actio n s should be taken, w ill depend upon the c ir c u m s ta n c e s . F o r exam p le , in the c a s e of a s m a ll sp ill of liquid it may be d e s ira b le to contain and c le a n up the contam in ation im m ed iately without se v e re ly cu rta ilin g the routine a c tiv it ie s in the room in which the s p ill o c c u rs . H ow ever, the r e le a s e of a re la tiv e ly la rg e quantity of a rad io activ e powder o r a e ro s o l in a room w ill re q u ire im m ed iate actio n to contain the contam in ation in the room and im m ed iate e v acu ation of the room by a ll p erso n n el, follow ed by e la b o ra te m onitoring and d econtam ination p ro ced u res . A ctions freq u en tly d e s ira b le i-n c a s e s of a cc id e n ta l r e le a s e s of rad io activ ity a re the s u b je c t of6 . 4 . 2 . - 6 . 4 . 1 7 . below . Although an attem pt is made to p resen t th e se actio n s in the approxim ate o rd e r in which they a re lik e ly to be ap p ro p ria te , som e of them w ill be ap p rop riate only in c a s e s of la rg e r e le a s e s o r under s p e c ia l cond itions.

6 . 4 . 2 . P e rs o n s in the v ic in ity of the s p ill o r r e le a s e who a re liab le to e ith e r e x te rn a l o r in te rn a l contam in ation as a re s u lt of the accid en t should be given ap p rop riate atten tion im m ed iate ly .

6 . 4 . 3 . The p ro tectio n of p erson n el and the containm ent of the ra d io activ e m a te r ia l in the room in w hich the accid en t o ccu rre d should be given p rim a ry co n sid era tio n . I f the sp ill o r r e le a s e is of such a nature that, in the judgem ent o f the p erso n im m ed iate ly re sp o n sib le fo r the w ork, it is advantageous to take im m ed iate actio n to contain the m a te r ia l o r lim it its r e le a s e , such actio n may be ap p ro p ria te .

6 . 4 . 4 . P e rs o n s d ire c tly contam inated by a s p ill should im m ed iate ly rem ove the clothing affected and thoroughly w ash the hands and o th er contam inated a re a s o f the body.

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6 . 4 . 5 . If an inhalation hazard e x is ts , a ll p erson s not involved in ca rry in g out planned sa fe ty p ro ced u res should leav e the contam inated a re a im m ed iate ly .

6 . 4 . 6 . E vacu atio n o r o th er action should be accom p lish ed with the m inim um req u ired m ovem ent about the ro om . M ovem ent should not s ta r t until the individual has con sid ered the situ ation and has d e te r m ined the purpose of h is m ovem ent. A rea s of known o r suspected contam in ation should be avoided.

6 . 4 . 7. The ra d io lo g ica l health and safe ty o f f ic e r o r h is re p re s e n tativ e in the a re a should be given a ll av a ilab le in form ation on the nature and extent of the r e le a s e .

6 . 4 . 8 . If evacu ation of the room is req u ired , it w ill g e n era lly be d e s ira b le to shut off a ll m ech an ica l ven tila tio n and to c lo se a ll outside openings. H ow ever, th e re may be lo ca l conditions which req u ire co n sid era tio n . F o r exam p le, if the r e le a s e o ccu rs in o r n e a r a fume hood, it m ay be disadvantageous to take any action which would d is continue ven tila tio n by the hood. When the room has been evacu ated , it should be c lo sed and w arning signs posted at the e n tra n ce .

6 . 4 . 9 . If co n sid erab le contam ination of the a ir is su sp ected , in halation of rad io activ e m a te ria l should be m inim ized by holding the b reath o r by use of such re s p ira to ry p ro tectio n as may be av a ila b le .

6 . 4 . 10. A fte r a ll p erso n s are out of the room , it m ay be d e s ira b le •to prevent fu rth e r escap e of rad io activ e m a te r ia l fro m the room by sea lin g doors and o th er c lo su re s with adhesive tape.

6 . 4 . 11. P e rs o n s su sp ected to have inhaled o r ingested s ig n ifican t q u an tities o f rad io activ e m a te ria l should seek o r be given im m ediate atten tion as d iscu ssed in 7. below.

6 . 4 . 12. E x ce p t in c a s e of in ju ry o r o th er urgent need, p erso n s who have le ft the contam inated a re a should not leav e the im m ed iate v ic i nity u n til they have been m onitored and n e c e s s a ry p recau tio n s, such as the rem o v a l of sh oes o r outer clothing, have been taken to lim it

■further sp read of rad io activ ity .

6 . 4 . 1 3 . The extent of the a re a of contam ination should be d eterm ined , the a re a roped off and appropriate w arnings o r guards posted.

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6 . 4 . 14. The p erso n in ch arg e of m e a su re s fo r dealing with accid en ts o r a d esignated a lte rn a te should arra n g e fo r im m ed iate d eco n tam ination o f p erso n n el and o th er m e a su re s as re q u ired .

6 . 4 . 15. The sa fe and e ffectiv e d econtam ination of the w orking a re a and equipm ent w ill g e n era lly re q u ire c a re fu l planning based on an evaluation of a ll fa c to rs involved. The sequ ence of p ro ced u res w ill g e n era lly be:

(a) To lo ca te and contain the contam ination;(b) To a s s e s s the contam ination and plan clean -u p o p eration s;(c) T o red u ce the contam in ation by app rop riate m ethods, and(d) T o a s s e s s the re s id u a l contam ination and rep ea t the d e

contam ination p ro ced u re as n e c e s s a ry .

6 . 4 . 16. P e rso n n e l ca rry in g out d econtam ination p ro ced u res should be provided with ap p rop riate in stru ctio n s and equipm ent both fo r th e ir own p ro tectio n and fo r that of o th e rs .

6 . 4 . 1 7 . N orm al w ork should not be resu m ed b efo re norm al conditions have been re s to re d and an announcem ent to that e ffe c t has been made by the p erso n in ch a rg e .

6 . 5 . A C CID EN TS INVOLVING ON LY E X T E R N A L RADIATION

6 . 5 . 1 . If only e x te rn a l rad ia tio n is involved, with the p o ss ib ility of high dose r a te s , the im portant m e a su re s to be taken include the im m ed iate evacu ation and c lo su re of the affected a re a , the posting of w arning s ig n s , the estim a tio n of d oses to a ll p erso n s concerned and the planning (in con su ltatio n with the ra d io lo g ica l health and sa fe ty o ffic e r ) to r e s to r e n orm al conditions in the w orking a re a .

7. DECONTAM INATION

7 . 1 . DECONTAM INATION O F PER SO N N EL

The ra d io lo g ica l health and sa fety o f f ic e r should e sta b lis h in s tru c tions and provide fa c i l i t ie s (m a te r ia ls and equipm ent) fo r norm al d econtam ination and f i r s t -a id p ro ced u res in con form ity with 1 .5 .4 .2 . above. The s ta ff should be fully acquainted with such p ro ced u res .

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7 . 1 . 1 . M e asu re s to be taken in ca se of in te rn a l contam ination ofp erso n n el

7 . 1 . 1 . 1 . In te rn a l rad io activ e contam ination of p erson n el can re su lt from in gestion , inhalation , a wound o r p en etra tion of the sk in . If in te rn a l contam in ation is su sp ected as a re s u lt of an accid en t during w ork, it should be im m ed iate ly rep orted to the ra d io lo g ica l health and sa fe ty o f f ic e r .

7 . 1. 1. 2 . In tern a l contam in ation is e ss e n tia lly a m ed ica l p roblem , p a ra lle l in som e ways to the ab so rp tion of ch e m ica l to x in s . Any sp e c ia l c o r re c t iv e p ro ced u res needed should th e re fo re be c a r r ie d out in com bination with n orm al m ed ica l attention and under m ed ica l advice and su p erv is io n .

7 . 1 . 1 . 3. The a im s of the c o r re c t iv e p ro ced u res a re :(a) T o try to e lim in a te quickly as m uch as p o ssib le of the

in te rn a lly in troduced contam inant s t i l l rem ain in g in the mouth, g a s tro - in te s tin a l o r re s p ir a to ry t r a c t , and to prevent o r reduce its uptake into the b loo d stream and t is s u e s ; and

(b) To try to prevent fixatio n o f the contam inant in the body o r to in c r e a s e its, e x cre tio n from the body.

7 . 1 . 1.-4. :F o r the f i r s t of th e se a im s it is so m etim es n e c e s s a ry that the contam inated p erso n o r another n o n -m ed ica l p erso n should take im m ed iate actio n (in the f i r s t second s o r m inu tes), fo r in stan ce to prom ote the m ech an ica l e lim in a tio n of the contam inant by inducing vom iting o r exp ecto ra tio n .

7 . 1 . 1 . 5 . In c a s e of a contam inated s m a ll open wound (cu t, puncture, e t c . ) ; the wound should be im m ed iate ly w ashed, bleeding should be encou raged i f n e c e s s a ry and the wound m onitored , and the m ed ica l o f f ic e r should be con su lted . B e ca u se the m onitoring of wounds is u su ally d ifficu lt and so m e tim e s im p o ss ib le , the im p lem ent cau sing the in ju ry should be re ta in ed fo r ca re fu l m onitoring .

7. 1 . 1 . 6 . F o r the second of the a im s indicated in 7. 1. 1. 3 . above, any fu rth e r p ro ced u re o f in te rn a l d econtam ination, e . g . m o re co m p lica ted c h e m ica l o r p h y s ico -ch e m ica l p ro ced u res , is a m a tte r of m ed ica l tre a tm e n t. It should be undertaken as soon as p o ssib le but only under m ed ica l su p erv is io n .

7 . 1 . 2 . M ea su re s to be taken in c a s e of e x te rn a l contam ination of p erso n n el

7 . 1 . 2 . 1 . E x te rn a l contam in ation of the p erso n can be a hazard in th re e w ays:

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(a) It may cau se in ju ry from lo ca l exp o su re o f the skin;(b) It m ay p e n etra te the in ta c t sk in (e s p e c ia lly in the p re sen ce

of c e r ta in o rg an ic so lv en ts); and(c) It m ay eventually be tra n sfe rre d into the body by in gestion o r

inhalation .

7. 1. 2 . 2 . The danger of loose activ ity being eventually c a r r ie d into the body is often the m o st c r i t i c a l hazard, so that d econtam ination p ro ced u res a re p r im a rily con cern ed with loose contam in ation .

7. 1 . 2 . 3 . As a ru le , excep t fo r d econtam ination of the hands o r in c a s e s o f em erg en cy as agreed upon by the ra d io lo g ica l health and sa fe ty o f f ic e r , a ll m ild decontam inating p ro ced u res d escrib e d in7. 1 . 2 . 4. and 7. 1 . 2 . 5. below should be c a r r ie d out under the su p e rv is io n o f the ra d io lo g ica l health and safety o f f ic e r . A ttem pts to rem ove contam in ation which r e s is t s mild p ro ced u res should be made only under m e d ica l su p erv is io n .

7 . 1 . 2 . 4 . The im m ed iate w ashing of contam inated a re a s with w ater and soap is the method of ch o ice fo r rem oving loose contam ination , s u b je c t to the follow ing e le m e n tary p recau tio n s;

(a) Tepid w ater should be used;(b) The soap should not be abrasive, nor highly a lkalin e;(c ) W ashing can be helped by scru bbing with a so ft b ru sh , but

only in such a way as not to abrade the skin; and(d) The sk in should be w ashed fo r a few m inutes at a tim e , then

dried and m onitored .W ashing can be rep eated i f n e c e s s a ry (as indicated by m onitoring) provided that th e re is no ind ication of damage to the sk in .

7. 1 . 2 . 5. If th is p ro ced u re fa i ls , a m ild d etergent approved by the ra d io lo g ica l health and sa fe ty o f f ic e r might be used , although r e peated ap p licatio n s of d etergen t to the sam e a re a of the sk in (hands,fo r in sta n ce) m ight in ju re it and m ake it p e n etrab le .

7. 1 . 2 . 6. The u se of o rg an ic so lvents o r of acid o r a lkalin e solutions should be avoided.

7 . 1 . 2. 7. S p e c ia l a tten tion should be paid to p ro p er d econtam ination of c r e a s e s , fo ld s, h a ir and such p arts of the hands as fin g e rn a ils , in te r - f in g e r sp ace and the o u ter edges of the hands.

7. 1 . 2 . 8 . C are should be taken to avoid as fa r as p o ssib le the sp read o f the contam in ation to uncontam inated p a rts of the body, and to avoid in te rn a l contam in ation . I f th e re is a r is k o f such sp read , an attem pt should f i r s t be made to rem ove the contam ination with ab sorb en t m a te r ia l, i f n e c e s s a ry , adequately co v erin g at the sam e tim e

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the ad jacen t non-contam inated a re a s o f the sk in . In g e n era l, an open wound should be p ro tected against any additional contam ination by decontam ination p ro ced u res applied to o th er a r e a s .7. 1 . 2 . 9 . A fte r each d econtam ination op eration , the tre a te d place should be d ried with a fre s h non -contam inated tow el, sw ab, e tc . and m onitored . A ll to w els, sw abs, e tc . so used should be tre a te d as contam inated m a te r ia l.7. 1 .2 . 10. W hile d econtam inating the fa ce , s p e c ia l c a re should be taken not to contam in ate the eyes o r lip s .7 . 1 . 2 . 1 1 . D econtam ination of the eyes should be undertaken im m e d ia te ly . Not only is the rad ionuclide to be co n sid ered , but also the c h e m ica l natu re o f the contam inant and p o ss ib le com p lica tion s due to fo re ig n bodies and m ech an ica l o r c h e m ica l i r r i ta n ts . Add ition al ir r ita t io n o f the ey es by d econtam ination p ro ced u res should be avoided. Im m ed iate ir r ig a tio n of the ey es with a copious amount o f w ater o r with ap p rop riate m ed ica lly approved so lutions is re c o m m ended. T h e se solutions and a su itab le v e s s e l fo r eye w ashing should be provided as f ir s t -a id k it. A fte r th is f i r s t p roced u re every ca s e of contam ination of the eyes should be subm itted to m ed ica l co n tro l and fu rth e r tre a tm e n t.

7. 1 . 2 . 12. A ttem pts to rem ove contam ination which r e s is t s washing should only be made under m ed ical su p erv isio n .

7 . 2 . DECONTAM INATION OF EQ U IPM EN T

7 . 2 . 1 . D econtam ination o f g lassw are and tools

7 . 2 . 1. 1. A d ecis io n to decontam inate m a te r ia l m ust take into account the continuing value o f the m a te r ia l com pared with the r is k s and co st of d econtam ination .

7 . 2 . 1 . 2 . W here the h a lf - l ife of the contam inating rad ionuclide is s h o r t , it m ay be d e s ira b le to s to r e to o ls and g la ssw a re fo r d ecay o f a c tiv ity ra th e r than to attem pt d econtam ination .

7 . 2 . 1 . 3. D econtam ination of equipm ent should g en era lly be done as soon as p o ss ib le a fte r its u se . In many c a s e s th is w ill prevent the contam inant from becom ing fixed and from being u ltim ate ly m ore d ifficu lt to deal w ith. It w ill often be found that s u r fa c e s that have been kept m o ist a re e a s ie r to c lean .

7 . 2 . 1 . 4 . The clean in g o f contam inated g la ssw a re and to o ls should be done with g re a t c a re by inform ed p erso n s in a w e ll-v e n tila te d hood s e t asid e in the la b o ra to ry fo r that purpose, o r in sp e c ia l d econtam in ation a r e a s .

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7. 2 . 1 . 5 . If i t is n e c e s s a ry to d ism antle any equipm ent b efo re d econtam in ation p ro ced u res , c a re fu l m onitoring should be c a r r ie d out during the o p eration .

7 . 2 . 1 . 6 . G lassw are can be cleaned by any of the n o rm al ch e m ica l ag en ts, o fw hich ch ro m ic acid solution is probably the m ost u sefu l. A ltern a tiv e clean in g agents a re con cen tra ted n itr ic acid , am m onium c itra te and o th er ch elatin g agents such as E D T A , as w ell as v ario u s p ro p rie ta ry clean in g m a te r ia ls .

7 . 2 . 1. 7. M etal to o ls and s im ila r equipm ent should be w ashed with a d etergent com bined with b r is k brushing to dislodge trapped co n tam in ation . C ontam ination r e s is t in g th is tre a tm e n t may be washed away with s tro n g e r ag en ts, including dilute n itr ic acid , a 10% so lu tion o f sodium c itr a te and o th er ch elatin g ag en ts. C leaning agents should be chosen taking into account the m a te r ia l o f w hich the equipm ent is made and the lik e ly ch e m ica l nature of the contam inant. S ta in le ss s te e l could be tre a te d with dilute su lphu ric acid o r a s u itable p o lish .

7 . 2 . 1 . 8 . If the d econtam ination ca u se s any c o rro s io n of the m etal, any fu ture contam ination w ill be m o re d ifficu lt to rem ove and a coat of g lo ssy paint on the d econtam inated su r fa ce is d e s ira b le . C ontam ination p revention by the use of strip p ab le coatin g s o r p la s tic co v ers is u se fu l. A coat of paint may provide adequate p ro tectio n again st soft rad ia tio n e m itte r s w hich prove re s is ta n t to d econtam ination .

7 . 2 . 1 . 9 . The uptake o f rad io activ e su b stan ce s by g la ssw a re m ay be reduced by a p re lim in a ry tre a tm e n t with a su itab le in activ e ch e m ica l.

7 . 2 . 1 . 1 0 . F o r som e c a s e s im m e rs io n in a solution o f a nonrad io activ e iso top e of the contam inant m ay be tr ie d , although th is is a slow p ro ced u re .

7 . 2 . 1. 11. The so lutions used fo r clean ing should not be retu rned to the sto ck b o ttles betw een u s e s .

7 . 2 . 1 . 1 2 . L a b o ra to ry equipm ent should be surveyed fo r re s id u a l contam ination follow ing d econtam ination p ro ced u res . If the re s id u a l contam in ation in d ica tes that the lev e l of activ ity re m a in s g re a te r than that sp ecified as p e rm is s ib le , the equipm ent should not be r e used but should be tre a te d as rad io activ e w aste .

7 . 2 . 2 . D econtam ination of w orking a r e a s , b en ch es, e tc .

7 . 2 . 2 . 1. As soon as p o ssib le a fte r contam in ation of w orking a re a s , b en ch es, e tc . has o ccu rre d o r has been d etected , decontam ination should be c a r r ie d out by su itab ly equipped and inform ed p e rso n s .

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7. 2 . 2 . 2 . A ll s u r fa c e s should be cleaned by wet methods i f p o ss ib le , as the use of dry m ethods may c r e a te a dust h azard . F o r porous co n stru ctio n m a te r ia ls which prove u n su scep tib le to clean ing by wet m ethods, vacuum clean in g with p ro p er filtra tio n of the re je c te d a ir m ight be attem pted; in any ca se sp e c ia l p recau tio n s in using dry techniqu es a re n e c e s s a ry .

7. 2 . 2 . 3 . C leaning to o ls should be assig n ed to the a re a in which the op eration s a re being p erform ed and should not be rem oved o r used e lsew h ere without ca re fu l decontam ination.

7. 2 . 2 . 4 . Paintw ork can be cleaned with soap o r d etergent and w ater o r , in e x trem e c a s e s , rem oved with a paint re m o v e r . Polyvinyl ch lorid e and polished linoleum can be cleaned with soap o r detergent and w ater; in the ca se of linoleum , w ashing m ay be follow ed, if n e c e s s a ry , by the rem o v al o f the wax p o lish by m eans of a so lvent.

7. 2 . 2 . 5 . If the contam ination is by alpha- o r so ft b e ta -e m itte r s , the rad ia tio n m ay p o ssib ly be con tro lled by painting o v er i t . The use o f two co a ts with the undercoat in a co n trastin g co lou r is u sefu l to in d icate any w earing away of the p ro tectiv e co a t. T h is method of contam in ation co n tro l should be used with cau tion with re s p e c t to fu ture p o ssib le u se s of the in sta lla tio n .

7. 2 . 2 . 6 . If a f te r attem pted d econtam ination adequate p ro tectio n cannot be a ssu re d , the contam inated room s o r p re m ise s should be abandoned and contam inated rem ov able o b je c ts d isposed o f in a c co rd an ce with the re q u irem en ts of the com petent authority . A c c e s s to such abandoned a re a s should be forbidden to unauthorized p e rso n s, which should be identified by an app rop riate and reco g n izab le w arning sign .

7 . 2 . 3 . D econtam ination o f clothing, h osp ita l linen and s im ila r item s

7. 2 . 3 . 1 . In any handling of contam inated clo th ing , ap p rop riate p re cau tions should be taken to co n tro l e x te rn a l exposure and a lso to p reven t o r co n tro l contam ination of the w o rk er and of the surrounding a re a s by the fo rm ation of a e ro s o ls . The so rtin g of contam inated g arm en ts as ind icated in 7. 2 . 3. 5 . below w ill often need to be c a rr ie d out in a fum e hood. C are m ust be taken to prevent a irb o rn e co n ta m ination from cloth ing p laced in s to ra g e .

7. 2 . 3 . 2 . C ontam inated clothing and linen should not be re le a s e d to a public laundry without the approval o f the ra d io lo g ica l health and sa fe ty o f f ic e r .

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7. 2 . 3 . 3 . In the c a s e o f sh o rt-liv e d rad io activ e contam in ation , s to rag e is recom m end ed u n til the activ ity has fa lle n to sa fe le v e ls .

7. 2 . 3 . 4 . It w ill usu ally be d e s ira b le to w ash contam inated cloth ing in s p e c ia lly provided laundering fa c i l i t ie s ; the a re a w here d eco n tam ination is c a r r ie d out should be m onitored . P e rso n n e l in ch arge of th e se fa c i li t ie s should be provided with p ro tectiv e co a ts and su itab le g lov es.

7. 2 . 3 . 5 . Contam inated g arm en ts should be seg reg ated into b atch es of d ifferin g d eg rees of activ ity to avoid cro ss -co n ta m in a tio n .

7. 2 . 3 . 6 . R outine w ashing of m o d erate ly contam inated cloth ing may be c a r r ie d out acco rd in g to p ro ced u res recom m end ed fo r c o m m e rc ia l laundry p r a c t ic e . H ow ever, it m ay be advantageous to su b stitu te a stand ard d etergen t (ch o sen on the b a s is of econom y) fo r soap b ecau se of the tendency o f the la t te r to form d ep osits w hich may fix the activ ity in the fa b r ic .

7. 2 . 3 . 7. C lothing with r e s is ta n t contam ination o r high lev e ls of a c tiv ity from lon g-liv ed rad ionu clid es may be su b jected to lon ger p eriod s of w ashing and e sp e c ia lly to rep eated r in s in g s .

7. 2 . 3 . 8 . R u b ber g loves and o th er ru b b er goods and p la s tic s usu ally d econtam inate re a d ily . Such item s should f i r s t be w ashed in a c co rd an ce with an o rd in ary laundry fo rm u la . If th is does not prove e ffe c tiv e , ru b b er item s can be w ashed in dilute n itr ic acid o r o th er agents chosen accord in g to the natu re o f the contam in ation . T h is should be follow ed by a w ash using sco u rin g powder and a thorough r in s e in running tap w ater.

7 . 2 . 3 . 9 . I f the clo th in g , lin en , e tc . cannot be d econtam inated to a s a fe le v e l i t should be tre a te d as rad io activ e w aste .

8 . RA D IO A C TIVE W A STE CON TROL AND D ISPO SA L 16

8 . 1 . W A STE C O LLEC TIO N

8 . 1 . 1 . Su itab le re c e p ta c le s should be a v a ilab le in a l l w orking p la ces w here ra d io a ctiv e w aste m ay o r ig in a te .

8 . 1 . 2 . Solid w aste should be deposited in re fu se bins with foot- op erated l id s . The bins should be lined with rem o v ab le p la stico r paper bags to fa c ili ta te rem o v al of the w aste without contam ination .

16 See also: The Management of Radioactive Wastes Produced by Radioisotope Users,Safety Series No. 12, IAEA, Vienna (1965); The Management of Radioactive Wastes Produced by Radioisotope Users: T ech n ical Addendum, Safety Series No. 19, IAEA, Vienna (1966).

49


8 . 1 . 3 . If no o th er fa c i l i t ie s fo r liq u id -w aste d isp o sa l e x is t , liquid w aste should be co lle c te d in b ottles kept in p ails o r tra y s designed to re ta in a ll th e ir contents in the event o f a b rea k a g e . C on tain ers a r e a v a ilab le fo r liquid w aste , which a r e provided with a su itab le ab so rb en t so that the w aste is held in a solid fo rm fo r subsequent s to ra g e o r d isp o sa l.

8 . 1 . 4 . A ll re c e p ta c le s fo r rad io activ e w aste should be c le a r ly id en tified . In g e n era l, it w ill be d e s ira b le to c la s s ify rad io activ e w aste acco rd in g to m ethods of s to rag e o r d isp o sa l, and to provide s e p a ra te co n ta in e rs fo r the variou s c la s s e s of w aste . Depending upon the need s of the in sta lla tio n , one o r m o re o f the follow ing b a se s fo r c la ss ify in g w aste m ay be found d e s ira b le :

(a) G am m a rad ia tio n le v e ls (high, low);(b) T o ta l a c tiv ity (high, m edium , low);(c) H a lf- life (long, sh o rt); and(d) C om bustible, n o n -co m b u stib le .

F o r convenient and p ositive id en tificatio n , i t m ay be d e s ira b le to use both co lou r coding and wording.

8 . 1 . 5 . Shielded co n ta in ers should be used when n e c e s s a ry

8 . 1 . 6 . It is g e n e ra lly d e s ira b le to m ain tain an ap p roxim ate re co rd of the q u an tities of rad io activ e w aste re le a s e d to d rainage sy stem s o r to s e w e rs , o r fo r b u ria l. T h is m ay be p a rticu la r ly im portant in the ca se o f lon g -liv ed ra d io iso to p e s. F o r th is purpose it m ay be d e s ira b le o r n e c e s s a ry to m ain ta in a re c o rd of estim ated q u an tities o f ra d io a ctiv ity deposited in v ario u s re c e p ta c le s , p a r t icu la r ly fo r high le v e ls o f activ ity o r lon g -liv ed rad io n u clid es . Depending upon the sy stem of co n tro l used by the in sta lla tio n ,it m ay be d e s ira b le to provide fo r the re c e p ta c le to be m arked or tagged with a s ta tem en t of its co n ten ts.

8 . 1 . 7 . R ad io activ e w aste should be rem oved fro m w orking p laces by designated p erson n el under com petent su p erv ision .

8 . 2 . W A STE STO RA G E

8. 2 . 1 . A ll w aste w hich cannot be im m ed iate ly d isposed of in co n fo rm ity with the re q u irem en ts of the com petent authority w ill have to be p laced in su itab le s to ra g e .

8 . 2 . 2 . S to rag e m ay be te m p o ra ry o r in d efin ite . T em p o rary sto ra g e is used to allow fo r d e c re a s e o f ac tiv ity , to p erm it re g u la tio n of the ra te o f r e le a s e of a c tiv ity , to p erm it m onitoring of

50


m a te r ia ls of unknown d eg ree of hazard o r to aw ait the a v a ila b ility of su itab le tra n sp o rt. Indefinite ce n tra liz e d s to ra g e in sp e c ia l p la ces m u st be provided by the com petent au th ority fo r the m o re hazard ou s w aste fo r which no u ltim ate d isp o sa l m ethod is a v a ilab le to the p a r tic u la r u s e r .

8 . 2 . 3 . S to rag e conditions should m e e t the sa fe ty re q u irem en ts fo r s to ra g e of so u rc e s se t fo rth in 4 . above.

8. 2 . 4 . The s to ra g e s ite should not be a c c e s s ib le to unauthorized p erso n n el. (C ontrol o f an im als should not be o v erlo o k ed .)

8 . 2 . 5 . The m ethod of s to rag e should p revent a cc id e n ta l r e le a s e to the su rrou nd ings.

8. 2 . 6 . A p p rop riate re c o rd s should be kept of the s to ra g e .

8 . 3 . E F F L U E N T R E L E A S E TO TH E EN VIRO N M EN T

8 . 3 . 1 . G e n e ra l co n sid eratio n s

8 . 3 . 1. 1. R ad io activ e efflu en t r e le a s e s to the environm ent should be c a r r ie d out in acco rd an ce with conditions esta b lish e d by the ra d io lo g ica l health and sa fe ty o f f ic e r and by the com petent au th ority .

8 . 3 . 1 . 2 . The ways in which ra d io a ctiv e m a te r ia ls m ay a ffe c t the environm ent should be ca re fu lly exam ined in re la tio n to any p ro posed m ethod o f efflu ent r e le a s e .

8 . 3 . 1. 3 . The cap acity o f any route o f d isp o sa l to accep t ra d io activ e effluent s a fe ly depends on the evaluation o f a num ber of fa c to r s , m any o f which depend on the p a r t ic u la r lo c a l s itu ation .B y assu m ing unfavourable conditions with re s p e c t to a ll fa c to r s , it is p o ss ib le to s e t a p e rm is s ib le le v e l fo r efflu ent r e le a s e which w ill be sa fe under a ll c irc u m s ta n c e s . T h is u su ally p rovid es a v e ry co n sid era b le sa fe ty fa c to r . T he r e a l cap acity o f a p a rtic u la r route o f effluent r e le a s e can only be found fro m a lengthy study by e x p e r ts .

8 . 3 . 1 . 4 . The s m a ll u se r should f i r s t try to w ork w ithin r e s t r ic t iv e l im its w hich a r e accep ted a s being sa fe and w hich w ill usu ally p ro vide a w orkable so lu tion to the p ro blem o f effluent r e le a s e . Such a r e s t r ic t iv e sa fe lim it m ay be a rriv e d at by identifying:

(a) The c r i t ic a l rad ionu clid e;(b) The c r i t i c a l pathway to m an;

51


(c) The c r i t i c a l group of the population concerned ; and(d) The critical organ..

T h e re a fte r i t w ill be p o ssib le to ca lcu la te the am ount and ra te of ra d io a ctiv ity that m ay sa fe ly be re le a s e d a t a given point in the environm ent, taking into account any a lte rn a tiv e re q u irem en ts the com petent au th ority m ay im pose if lo c a l stud ies by e x p e rts provide re a so n a b le ju s tif ic a tio n fo r o th er le v e ls . M ore d etailed guidelin e s fo r th is e x e r c is e can be found in the ap p rop ria te Safety S e r ie s pu blication s of the A gency. In p ra c t ic e , how ever, the s m a ll u s e r seldom re q u ire s to go into such d etailed con sid eratio n s s in ce the type o f w ork and the am ount and natu re o f the rad ionuclide involved would not in a ll p ro bab ility pose a s ig n ifican t environm ental p ro b lem .

8 . 3 . 2 . E fflu en t r e le a s e to d rains and sew e rs

8 . 3 . 2 . 1. The r e le a s e o f rad io activ e efflu ent into d rain s does not u su ally need to be con sid ered as a d ir e c t r e le a s e into the en v iro n m ent. H en ce, a r e s t r ic t iv e safe lim it w ill u su ally be provided i f the co n cen tra tio n o f rad io activ e efflu en t, based on the to ta l availab le flow o f w ater in the sy stem averaged o v er a m o d erate period (a day o r a m onth), does not lead to exp osu re o f individual m em b ers of the public to d oses in e x c e s s of the dose l im its p re scr ib e d in the A gency1 s B a s ic Safety Standards fo r R ad iation P r o te c t io n 17. In a rr iv in g at the dose ra te s and am ounts of d isch arg e the fa c to rs su m m arized in 8 .3 .1 .4 . above m ay need to be con sid ered in som e c a s e s . F in a lly , b e fo re r e le a s e o f rad io activ e effluent to public d ra in s , se w e rs o r r iv e r s , the com petent authority should be con su lted to a s c e r ta in that no o th er rad io activ e effluent is being r e lea se d in such a way that the accum ulated r e le a s e s w ill c re a te a h azard ou s situ ation .

8 . 3 . 2 . 2 . R ad ioactiv e r e le a s e to d ra in s should be re ad ily so lu b le o r d is p e rs ib le in w ater. Account should be taken of p o ssib le changes of pH due to dilution o r o th er p h y s ico -ch e m ica l fa c to r s , w hich m ight lead to p rec ip ita tio n o r vap orizatio n of diluted m a te r ia ls .

8 . 3 . 2 . 3 . In g e n era l, the e x c re ta of p erson s being tre a te d by rad io iso to p es do not c a ll fo r sp e c ia l co n sid eratio n .

8. 3 . 2 . 4 . W astes should be flushed down the pipe by a copious s tre a m of w ater.

11 Safety Series No. 9.

52


8 . 3 . 2 . 5 . The dilution o f rad io activ e effluent by the addition o f s ta b le iso to p es o f the rad io activ e e lem en ts p re se n t in the efflu ent m ay be co n sid ered .

8. 3 . 2 . 6 . M aintenance w ork on a c tiv e d rains w ithin an e s ta b lis h m ent should only be c a rr ie d out with the knowledge of the ra d io lo g ic a l health and sa fe ty o f f ic e r and under com petent su p erv is io n .S p e c ia l atten tion should be given to the p o ss ib ility that sm a ll so u rce s m ay have been dropped into sinks and re ta in ed in tra p s o r catch m en t b a s in s .

8. 3 . 2 . 7 . The r e le a s e o f rad io activ e effluent to se w e rs should be done in such a m ann er as not to re q u ire p ro te ctiv e m e a su re s during m ain tenance w ork on sew e rs outside the e sta b lish m e n t, u n le ss o th er ag reem en t has been reached with the au thority in ch arge o f th o se s e w e rs . T h is au thority should be inform ed o f the r e le a s e o f rad io activ e effluent into the sew er sy stem ; m utual d iscu ss io n o f the te ch n ica l a sp e cts o f the w aste d isp o sa l p roblem is d e s ira b le to provide p ro te ctio n , avoiding u n n ece ssa ry anxiety .

8 . 3 . 3 . E fflu en t r e le a s e to the atm osphere

8 . 3 . 3 . 1 . Any r e le a s e o f rad io activ e effluent in the fo rm o f g a se s o r a e ro s o ls into the a tm o sp h ere should conform with the re q u irem en ts of the com petent au th ority .

8. 3 . 3 . 2 . If p ro tectio n is based on an elevated r e le a s e point fro m a s ta c k , le v e ls o f r e le a s e should only be s e t a fte r exam ination of lo c a l conditions by an e x p e rt.

8 . 3 . 3 . 3 . The need fo r filtra tio n of g ases o r a e ro s o ls b e fo re r e le a s e a s w aste should be a s s e s s e d .

8 . 3 . 3 . 4 . U sed f i l t e r s should be handled as so lid w aste .

8 . 3 . 4 . B u r ia l of w aste

8 . 3 . 4 . 1 . B u r ia l of w aste in s o il so m etim es provides a m easu re of p ro tectio n not obtained i f the w aste is re le a se d d ire c tly to the environm ent. The p o s s ib ilit ie s of sa fe b u ria l of w aste should alw ays be ap p raised by an e x p e rt.

8 . 3 . 4 . 2 . B u r ia l under a su itab le depth of s o il (about one m e tre ) p rov id es eco n o m ica l p ro tectio n fro m the e x te rn a l rad ia tio n of the accu m ulated d ep osit.

8 . 3 . 4 . 3 . A b u ria l s ite should be under the co n tro l of the u s e r , and adequate step s to exclud e the public from it should be taken .

53


8 . 3 . 4 . 4 . A re c o rd should be kept of d isp o sa ls into the ground.

8 . 3 . 5 . In c in era tio n of w aste

8 . 3 . 5 . 1 . If so lid w aste is in cin erated to red u ce the bulk to m anageable p ro p o rtio n s, adequate p recau tio n s should be taken .

8 . 3 . 5 . 2 . The in c in e ra tio n of activ e w aste should only be c a rr ie d out in equipm ent em bodying such fe a tu re s fo r f i ltra tio n and scru bbing as m ay be n e c e s s a ry fo r the le v e ls of activ ity to be d isposed of.

8 . 3 . 5 . 3 . R esid u al ash es should be prevented from becom ing a dust hazard , fo r exam ple by damping them with w ater, and should be p ro p erly dealt with as active w aste .

54


APPENDICES

APPENDIX 1

DERIVED CONCENTRATION LIMITS OF RADIONUCLIDES IN AIR AND WATER FOR OCCUPATIONAL EXPOSURE

Note: The figures in the tables of Appendix 1 will be revised and brought up to date from time to time

as appropriate, based on the latest 1CRP figures.

A l-1 . EXPLANATION OF SOME OF THE TERMS USED

Rad: The unit of absorbed dose. 1 rad = 0.01 J/kg = 100 erg/g.

Dose equivalent: The response of a biological system to ionizing radiation depends on a number of factors, namely: (1) the energy absorbed at the place of interest; (2) the energy tran sfer pattern within the system ; (3) the rate at which the energy is absorbed; and,in the case of internally deposited radionuclides, (4) the spatial distribution of the radioelement. Thus, for radiation protection purposes, it is useful to define a quantity which is termed the dose equivalent (H). The unit of dose equivalent is the rem . The dose equivalent is num erically equal to the product of absorbed dose (D), quality factor (Q), and other necessary modifying factors (N) introduced to obtain, for the purposes of radiation protection, a quantity that expresses, on a scale common for all ionizing radiation, the irradiation incurred by the exposed person. Thus,

H = DQN

where H is expressed in rem s and D is expressed in rads, taking account of item (1) above. The quality factor Q takes account of item (2) above. With respect to item (3), within the dose limits'recommended for radiation protection purposes laid down in the Agency1 s B asic Safety Standards for Radiation Protection (1967 Edition)*, dose rates need not be taken into account. Provision for other factors is also made. Thus a distribution factor may be used to account for the modification of the biological effects due to non-uniform distribution of internally-deposited radioactive m aterial required by item (4). This factor has been taken into account in the derivation of the lim its for intake of radionuclides into the body. The Q- values that should be used for radiological protection purposes are listed in Tables A l-Ia , A l-Ib , A l-Ic . In the text below, the term s dose and dose equivalent are used interchangeably.

* Safety Series No. 9.

55


T A B L E A l- I a . V A LU ES O F Q U A LITY FA C T O R DEFIN IN G DOSE EQ U IVA LEN T

Q a USED IN

Radiation Q

X-rays, y-rays, electrons and 6-rays 1. oFast neutrons and protons up to 10 MeV*3 10

a -p artic les from radioactive decay (for internal exposure) 10

Heavy reco il nuclei 20

a These values of Q are those chosen specifically for use in defining maximum permissible doses.

k When the neutron or proton energy is more closely defined, the values of Q in Tables A l-Ib and A l- I c may be used.

T A B L E A l- Ib . R ELA TIO N SH IP B E T W E E N DOSE EQ U IV A LEN T AND NEUTRON F L U X D EN SITY

Neutron energy Q a

Flux density equivalent to 2. 5 mrem/h (n/cm z s '1 )

Fluence equivalent to 1 rem

(n/cm 2)

Therm al 3 .0 670 9. 6 x 10®

5 keV 2 .5 570 8 .2 X 108

20 keV 5 .0 280 4. 0 x 108

100 keV 8. 0 80 1 .2 x 10s

500 keV 10. 0 30 4. 3 x 107

1 MeV 10. 5 18 2. 6 x 107

5 MeV 7 .0 18 2. 6 x 107

10 MeV 6. 5 17 2 .4 x 107

20 MeV 6 .0 10 1 .5 x 107

50 MeV 5 .2 7 1. 0 x 107

100 MeV 4 .7 6 .3 9. 0 x 106

200 MeV 4 .0 4 .5 6. 5 x 106

500 MeV 3 .5 2 .2 3. 2 x 10s

1000 MeV 3 .5 1 .1 1 .6 x 10s

These values o f Q are those chosen specifically for use in defining maximum permissible doses.

56


T A B L E A l - I c . V A LU ES O F Q U A LITY FA C T O R Q a FO R PRO TO N E N E R G Y O F 50 - 1000 MeV

Proton energy (MeV)

Q

50 1 .2

100 1 .3

200 1 .7

300 2. 0

500 2. 5

700 2. 8

1000 3. 2

3 These values of Q are those chosen specifically for use in defining maximum permissible doses.

A l-2 . DERIVED LIMITS FOR CONTROLLABLE EXPOSURE

The lim its of doses for controllable exposure are given in detail in the Agency1 s B asic Safety Standards for Radiation Protection (1967 Edition)*. To ensure, in the case of internal radiation exposure, that the maximum perm issible doses and dose lim its are not exceeded, derived lim its are available for practical application. The more appropriate derived lim it for this purpose would be the body or critica l organ content of the radionuclides giving the maximum perm issible dose rate . However, in practice, the use of this derived lim it is not easy and therefore another derived lim it which may be used is the maximum perm issible annual intake in air or water, subject to the qualifications indicated in the B asic Safety Standards. The intakes are given in Tables IIA and IIB in the B asic Safety Standards. However, the estim ation of intakes is not always easy and, for practical control of internal exposure, a third derived standard is used, i .e . the derived concentration lim it (DCL), form erly known as maximum perm issible concentration. The derived concentration lim it is not given in the B asic Safety Standards, though a method of computing is indicated. F o r the convenience of the

* Safety Series No. 9.

57


user, DCL values for occupational exposure are given in Tables A l-IIa , b ,c ,d . Derived air concentration (DAC) and derived water concentration (DWC) are also given for practical convenience. F o r control purposes, keeping within the DCL will ensure that the dose equivalent to the worker does not exceed the maximum perm issible dose for occupational exposure, provided there is no external exposure. It should be noted that the DCL values in Tables A l-IIa , b, c , d apply to workers only. Furtherm ore, in practice, the DWC values should normally be of technical interest only, since workers should not, at their working place, consume water containing radioactivity at higher concentrations than in public water supplies.

58


T A B L E A l- I Ia . D ERIV ED CONCENTRATION L IM IT S O F RADIONUCLIDES IN AIR AND W A TER F O R OCCUPATIONAL EX P O SU R E (40 h/week)

Radionuclide C ritical organ a

Organ content giving maximum

permissible dose rate

UxCi)

Derived air concentration

QiCi/cm3)

Derived water concentration ̂

(ingestion) (pCi/cms )

JH (HTO or sH20 ) (soluble) Body tissue 5 x 1 0 "6 0 .1Total body 1. 2 x 10s

( 3H ,) (submersion) Skin 2 X 1 0 " s

jBe (soluble) GI(LLI) Total body 5. 6 x 102 6 x 1 0 "6

0 .0 5

(insoluble) LungGI(LU)

52 1 0 "60. 05

“ c (CO,) (soluble) Fat 1. 6 x 10* 4 x 10‘ 6 0 .0 2

(submersion) Total body 5 x 10“*

“ F (soluble) GI(SI) 5 X 10-6 0. 02

(insoluble) GI(ULI) 3 x 10‘ « 0 .01

” Na (soluble) Total body 12 2 x 1 0 " 7 io-»

(insoluble) Lung GI (LLI)

1 9 x 10-99 x 10“4

> (soluble) GI (SI) 1 0 '6 6 x 1 0 "8

(insoluble) GI (LLI) 10" 7 8 x 10" 4

“ Si (soluble) GI (S) 6 X 10“ 6 0. 03

(insoluble) GI (ULI) 10"« 6 x 1 0 "3

S ' (soluble) Bone 3.1 7 X 10-8 5 x 1 0 "4


1 .2 8 x 10-*7 X 10-4

S5o Testis 0 .2 3 x 1 0 " i 1 x 10“ *


15 3 x 10”78 x 10‘ 8

S c i (soluble) Total body 75 4 x 1 0 "7 2 x 10" 3


3 . 2 2 x 10"*2 x 1 0 "3

“ Cl (soluble) GI (S) 3 x 10-6 0. 01

(insoluble) GI (S) 2 x 1 0 "6 0.01

« A T18 (submersion) Skin 6 x 10-3

41 Ar uAr (submersion) Total body 2 x 10’ 6

aThe abbreviations GI, S, SI, ULI, and LLI refer to gastro-intestinal tract, stomach, small intestine, upper large

intestine, and lower large intestine, respectively, k The derived water concentration values should not be interpreted to mean that the worker is liab le, at his working place,

to drink water containing radioactivity at higher concentrations than in public water supplies.

59


TA BLE A l- I Ia (cont.)

Radionuclide C ritical organ



(MCi)


(pCi/cm5)

Derived water concentration

(ingestion) 0iCi/cm s)

“ K (soluble) GI (S) 2 x 10"6 9 x 10“ 8

(insoluble) GI (LLI) 1 0 - ’ 6 x 1 0 '*

S c * (soluble) Bone 26 3 x 10‘ « 3 x 10‘ 4


9 .7 io - i5 x 10“»

!'oCa (soluble) Bone 4 .2 2 x 10‘ 7 10**

(insoluble) GI (LU) Lung 1

2 x 1 0 "7 2 x 10’ 7

10-s

“ Sc (soluble) GI (LLI) Liver 2 .2

2 x 10"7 2 x 1 0 '7

10- !


1 .3 2 x lO-810-3

!IS c (soluble) GI (LLI) 6 x 10‘ 7 3 x 10’ »

(insoluble) GI (LLI) 5 x 1 0 "T 3 x 10"*

Wel l ^ (soluble) GI (LU) 2 x 10’ 7 8 x 10"4

(insoluble) GI (LLI) 10-T 8 x 10‘ 4

4 8 y 13 V (soluble GI (LU) * 2 x 1 0 '7 9 x 1 0 "4


0. 93 6 x 10-»8 x 10’ 4

S Cr (soluble) GI (LLI) Total body 780

10‘ s1 0 -s

0 .0 5


60 2 x 10-«0 .0 5

(soluble) GI (LLI) 2 x 10-7 10-s


0. 87 10-*9 x 1 0 "4

“ Mn (soluble) GI (LU) Liver 6 .2 4 x 1 0 "7

4 X 10" 5

(insoluble) Lung GI (LU)

3 .6 4 x 10"*3 x 10“ 8

“ Mn (soluble) GI (LU) 8 x 10" T 4 x 10“ s

(insoluble) GI (LLI) 5 x 1 0 "7 3 x 10“ *

(soluble) Spleen 19 9 x 10" 7 0. 02


130 10‘ 60. 07

60


TABLE A l- I Ia (cont.)




OiCi)


QiCi/cm*)



g f e ^soluble) GI (LLI) Spleen 0.37 io - i

2 x 10’ 8


2 5 x 10-»2 x 10"s

JJCo (soluble) GI (LU) 3 x 10*® 0. 02


16 2 x 10"70. 01

»C o m (soluble) GI (LLI) 2 x 10"5 0 .0 8


4 .2 9 x 10“60 .0 6

21 . (soluble) GI (LLI) Total body 32

8 x 10’ 7 4 x 10"*

(Insoluble) Lung GI (LU)

3 5 x 10"83 x 1 0 '8

g c » (soluble) GI (LU) Total body 13

3 x 10”7 io -*


1 .2 9 x 10’ 910-s

gNi (soluble) Bone 1400 5 x 10"7 6 x 10‘ 8


110 8 x 10‘ 70 .0 6

S « (soluble) Bone 100 6 x 10-® 8 x 1 0 "4


40 3 x 10’ 70 .0 2

S n i (soluble) GI (UU) 9 x 10"7 4 X 10~8

(Insoluble) GI (ULI) 5 x 10’ 7 3 x 10“s

»Cu (soluble) GI (LLI) 2 x 10"« 0. 01

(insoluble) GI (LU) 10“« 6 x 10"s

£ Z " (soluble) Total bodyProstateUver

610 .19 .5

10“71 0 -710-7

3 x 10"8


6 .6 6 X 10-*5 x 10"8

t’.Znm (soluble) GI (LLI) Prostate 0 .0 1 3

4 X 10“7 4 x 10"7

2 x 10‘ J

(insoluble) GI (LLI) 3 X 10"7 2 x 10-8

61


TABLE A l- I I a (cont.)

Radionuclide Critical organ



(MCi)


0iCi/cm s)


(ingestion) (fiCi/cms)

?.Zn (soluble) GI (S) 0 .0 5Prostate 0 .015 7 x 10‘ *

(insoluble) GI (S) 9 x 1 0 '6 0 .0 5

«Ga (soluble) GI (LU) 2 x 10’ 7 1 0 's

(insoluble) GI (LLI) 2 x 1 0 "7 10-s

«Ge (soluble) GI (LLI) 10"s 0. 05


84 6 x 10"60 .0 5

! !as (soluble) GI (LLI) Total body 320 2 x 10’ *

0 .01


20 4 x 1 0 '70. 01

S as (soluble) GI (LLI) 3 x 10"7 2 x 10‘ 8


2 .2 10-72 x 10“3

",As (soluble) GI (LLI) 1 0"7 6 x 10- 4

(insoluble) GI (LLI) 10-7 6 x 10"4

S a > (soluble) GI (LLI) 5 X 10’ 7 2 x 10"3

(insoluble) GI (LLI) 4 x 10"7 2 x 1 0 -3

” Se (soluble) Kidney Total body

3 .598

10’ 610‘ 6

9 x 10-s


8 .9 10“78 x 10"*

> (soluble) Total body GI (SI)

11 10"6 8 x 10*> 8 x 10-3

(insoluble) GI (LLI) 2 x 10"7 io->

“ Krm (submersion) Total body 6 x 10"6

SK r (submersion) Total body 1 0"s

£ K r (submersion) Total body 10-«

srRb (soluble) Total body 28 3 x 1 0 "7 2 x 10’ 3Pancreas 0 .0 9 3 x 10”7 2 x 10"3Liver 2 .2


1 .3 7 x 10_#7 x 10“4

62


T A BLE A l- I Ia (cont.)




OiCi)


(jjC i/cm 3)


(ingestion) (pCi/cm8)

«Rb (soluble) Pancreas Total body Liver

0. 065 220

16

5 x 10-7 3 x lO-3


9 .3 7 x 10“»5 x 1 0 "3

(soluble) GI (SI) 4 x 1 0 "5 0 .2

(insoluble) GI (SI) 3 x 1 0 "s 0 .2

85Sr (soluble) Total body 59 2 x 1 0 *7 3 x 1 0 "s


5 .2 10"15 x 1 0 "8

” Sr (soluble) Bone 3 .9 3 x 10"* 3 x 1 0 '*


1 .5 4 x 10‘ 88 x 1 0 "4

S8Sr (soluble) Bone 2 l x l O " 9 1 x 10" 5


0 .76 5 x 1 0 "91 0 '3

9to_s»or (soluble) GI (LU) 4 x 10’ 7 2 x 10“ 8

(insoluble) GI (LLI) 3 x 10‘ 7 10-8

92c.3Sbt (soluble) GI (UU) 4 x 10" T 2 x 1 0 "8

(insoluble) GI (ULI) 3 x 1 0 '7 2 x 10‘ 3

90v391 (soluble) GI (LLI) 1 0 '1 6 x 10“4

(insoluble) GI (LLI) 1 0 "1 6 x 10" 4

9i«-ro» r (soluble) GI (SI) 2 X 1 0 ' s 0.1

(insoluble) GI (SI) 2 x 10“5 0 .1

91y89 (soluble) GI (LU)

Bone 3 .8 4 X 10-*3 x 1 0 "4


1 .4 3 x 10‘ *8 X 10‘ 4

92yS9 (soluble) GI (ULI) 4 x 1 0 "7 2 x 10"8

(insoluble) GI (ULI) 3 x 10"T 2 x 10"8

s * (soluble) GI (LLI) 2 x 10“7 8 x 10“ 4

(insoluble) GI (LLI) 10-T 8 x 10" 4

63


TA BLE A l- I I a (cont.)




feCl)


OiCi/cm3)


(ingestion) (jiCi/cm*)

5 ,7 r 40 " r (soluble) GI (LLI) Bone 100 10-*

0 .0 2


43 3 x 10‘ T0 .0 2

(soluSle) GI (LLI) Total body 18 10’ 7

2 x 10’ s


1 . 6 3 x 10‘ *2 x 10-s

> (soluble) GI (LU) 1 0 '1 5 x 10’ 4

(insoluble) GI (LLI) 9 x 10-* 5 x 10’ *

(soluble) GI (LLI) Bone 91 10-t

0.01

(insoluble) Lung GI(LLI)

22 2 x 10“70.01

“ N b (soluble) GI (LLI) Total body 38 5 x 10‘7

3 x 10"*

(Insoluble) Lung GI (LLI)

3 .2 10‘ 73 x 10"*

” Nb (soluble) GI (ULI) 6 x 10"6 0 .0 3

(insoluble) GI (ULI) 5 x 10"« 0. 03

«M o (soluble) Kidney GI (LLI)

0 .56 7 x 10-7 5 x 10‘ *

(insoluble) GI (LU) 2 x 10"7 10"*

; 'T c m (soluble) GI (LLI) 8 x 10“s 0 .4


1 .3 3 x 10"s0 .3

41 Tc (soluble) GI (LLI) 6 x 10’ 7 3 x 10“*

(insoluble) GI (LU) 2 x 10-7 10-3

« T c m (soluble) GI (LLI) 2 x 10"« 0 .0 1


9 .3 2 x 10“75 x 10‘ *

15 Tc (soluble) GI (LU) Kidney 13

10"s10*s

0. 05


42 3 x 10’ 70. 02

64


T A B L E A l - n a (cont.)




(MCi)


QiCi/cm*)



r ,T cm (soluble) GI (ULI) 4 x 10"5 0 .2

(insoluble) GI(ULI) 10-s 0 .0 8

r , T c (soluble) GI (LLI) 2 x 10"« 0 .0 1


8 .9 6 x 10"*5 x 10‘ ®

> (soluble) GI (LLI) 2 x 10-« 0 .01

(insoluble) GI (LLI) Lung

2 x 10"6 2 x 10"6

0. 01

‘JJRU (soluble) GI (LLI) 5 x 10"7 2 x 10‘ 3


3 .1 8 x 10‘ ®2 x 1 0 "s

■ > (soluble) GI (UL1) 7 x 10"7 3 x 10“s

(insoluble) GI (UU) 5 x 10"7 3 X 10"*

‘“ Ru (soluble) GI (LU) 8 x 10- * 4 x 10"4


0 .6 6 x 10”®3 x 10"4

‘J j R h 01 (soluble) GI (S) 8 x 10'S 0 .4

(insoluble) GI (S) 6 x lO -5 0 .3

(soluble) GI (LU) 8 x 10“7

oX

(insoluble) GI (LU) 5 x 1 0 '7 3 x 1 0 '*

(soluble) GI (LU) Kidney 4 .1 0 10"«

0. 01


13 7 x 1 0 '78 x 10**

(soluble) GI (LLI) 6 x 10“T 3 x 1 0 '5

(insoluble) GI (LLI) 4 x 1 0 '7 2 x 10"*

‘S * g (soluble) GI (LLI) 6 x 10‘ 7 3 x 10"*


2 .9 8 x 10-»3 x 10"*

‘i;A gm (soluble) GI (LLI) 2 x 10‘ T 9 x 1 0 "4


10"®9 x 1 0 "4

65






(MCi)


(fiCi/cm8)


(ingestion) 0iCi/cm J )

Jii *47 8 (soluble) GI (LU) 3 x 10-7 10-)

(insoluble) GI (LU) 2 x 1 0 "7 10-s

*gCd (soluble) GI (LLI)UverKidney

142 .6

5 x 10’ 85 x 10’ 8


8 .4 7 x 1 0 "85 x 10“s

“ le d " 1 (soluble) GI (LLI)LiverKidney

2 .3 4 x l ( f # 4 x 10’ 8

7 x 10“*


1 .4 4 x 1<T*7 x 10‘ 4

‘ifCd (soluble) GI (LLI) 2 x 1 0 "7 10” 8

(insoluble) GI (LLI) 2 x 10-7 10-8

‘“ i n " (soluble) GI (ULI) 8 x 10"« 0. 04

(insoluble) GI (ULI) 7 x 10‘ 4 0. 04

i u . m49 (soluble) GI (LU)

Kidney Spleen

0.27 0 .1 4

1 0 -7 1CT7 10 - i

5 x 10‘ 4

(insoluble) GI (LU) Lung 0. 89 2 x 10-8

5 x 1 0 "4

m Inm49 (soluble) GI (ULI) 2 x 10"« 0. 01

(insoluble) GI (ULI) 2 x 1 0 "6 0. 01

u , <5nso5 n (soluble) GI (LU) Bone 16 4 x 10’ 7

2 x 10_s


3 .6 5 x 1 0 '82 x 10“ 8

■> (soluble) GI (LLI) 1 0 '7 5 x 1 0 '4


0. 87 8 x 10’ 85 X 1 0 '4

i?S b (soluble) GI (LU) 2 x 10‘ 7 8 x 10' 4

(insoluble) GI (LLI) 1 0 " 7 8 x 1 0 "4

‘“ Sb (soluble) GI (LU) Total body

2 x 10" 7 2 x 1 0 *7

7 x 1 0 '4


0.91 2 x IQ "87 x 1 0 '4

6 6






(MCi)


OjCi/cm3)



1J5C. 51 S b (soluble) GI (LLI)

LungTotal body Bone

3 .35618

5 x 10‘ 73 x 1 0 -J


3 .3 3 x 1 0 "®3 x 10‘ 3

125 r e m52 (soluble) Kidney

GI (LU) Testis

1 . 8

0 . 1

4 x 10"7 5 x 10-s 5 x 10"s


6 10-73 x 1 0 "3

W’ T . m (soluble) Kidney 0 .79 10"7 2 x 1 0 "sTestis 0. 063 10‘ 7 2 x 10-3GI (LU) 2 x 1 0 "3


2 .6 4 x 10"82 x 1 0 "5

127 Te S2 l e (soluble) GI (LU) 2 x 10“« 8 x 1 0 "J

(insoluble) GI (LLI) 9 x 10"7 5 x 10‘ 3

- T e - (soluble) GI (LLI) 1 0 "3Kidney 0. 32 8 x 10" 8 10"3Testis 0. 016 1 0 "3


1 3 x 10“86 x 10"4

” ’ Te (soluble) GI (S) 5 x 10"« 0 .0 2

(insoluble) GI (ULI) 4 x 10“6 0 .0 2

191 T_m52 (soluble) GI (LLI) 4 x 10“7 2 x 10"3

(insoluble) GI (LU) 2 x 10"’ 10-3

132 Te 52 l e (soluble) GI (LLI) 2 x 10"7 9 x 10"*

(insoluble) GI (LLI) 10-T 6 x 10’ *

126 t 531 (soluble) Thyroid 0. 21 8 x 10"® 5 x 1 0 '5


4 .7 3 X 10‘ T3 x 10-3

129 « 531 (soluble) Thyroid 0 .49 2 x 10-9 10‘ 5


10 7 x 10"86 x 10"3

67



Radionuclide C ri tic a l organ

Organ content giving m axim um

perm issible dose rate

(MCi)

D erived air concentration

(jiC i/ cm s)

D erived water concentration

(ingestion) (jiC i/ cm 3)

131Tss1 (soluble) Thyroid 0 .1 5 9 x 10** 6 x 10“5

(insoluble) GI (LLI) Lung 2 .8

3 x 1 0 "7 3 x 1 0 "T

2 x 10"s

i t t ,531 (soluble) Thyroid 0. 052 2 x 1 0 "7 2 x 1 0 '*

(insoluble) GI (ULI) 9 x 10"7 5 x 1 0 '*

133. 531 (soluble) Thyroid 0 .062 3 x 1 0 "8 2 x 10’ 4

(insoluble) GI (LLI) 2 x 10*7 10 "3

134,53* (solu ble) Thyroid 0.041 5 x 1 0 "7 4 x 10"*

(insoluble) GI (S) 3 x 10"6 0 .0 2

135tS31 (solu ble) Thyroid 0. 065 1 0 -7 7 x 1 0 "4

(insoluble) GI (LLI) 4 x 10*7 2 x 10-*

‘" X e 1" (subm ersion) T o ta l body 2 x 1 0 "5

‘g X e (subm ersion) T o ta l body 10-s

‘ £ X e (subm ersion) T o ta l body 4 x 1 0 "6

“ c* (soluble) T o ta l body l iv e r

68060

1 0 "510"*

0. 07

(insoluble) Lung G I (LLI)

35 3 x 10*«0 .0 3

‘s“ C Sm (soluble) G I (S) 4 x I0 ’ s 0 .2

(insoluble) G I (ULI) 6 x 10"6 0. 03

‘S ' * (soluble) T o ta l body 18 4 x 10‘ 8 3 x 10"4

(insoluble) Lung G I (LLI)

1 .5 10-81 0 "s

‘S c * ' (soluble) Liver Spleen T o ta l body

221 .9

300

5 X 10" 7 5 x 10" 7

3 x 10"3

(in soluble)

3 I

13 9 x 10"*7 x 1 0 "3

‘ SC* (solu ble) T o ta l body 30 4 x 10‘ 7 2 x 10“*


2 .4 2 x 10*72 x 10’ *

6 8






(MCI)


(pCi/cm3)


(ingestion) (pCi/cm s)

‘£ c s (soluble) Total body Liver Spleen Muscle

333 .50 .3 4

14

6 x 10’ * 4 X 1 0 ‘ *


2 10*8lo ”

(soluble) GI (LLI) 10"6 5 X 1 0 ' 1


4 .4 4 x 10“75 X 1 0 ‘ 3

(soluble) GI (LLI) Bone 2.6 10-7

8 X 1 0 ‘ *


0.6 4 x 10“8i x i< r‘

‘"L aST (soluble) GI (LLI) 2 x 10“7 1 X 1 0 - ‘

(insoluble) GI (LU) 10‘ 7 7 X 1 0 " ‘

141 Ce 58 (soluble) GI (LLI)UverBone

7 .914

4 x 10"73 x 1 0 - ’


4 .7 2 x 10“73 X 1 0 " !

MC« (soluble) GI (LLI) 3 x 10-’ 10"»

(insoluble) GI (LLI) 2 x 10*7 io->

' S Ce (soluble) GI (LLI)BoneUver

1.7 10“810“8

3 X 1 0 ‘ *


0. 64 6 x 10’ 93 X 1 0 - ‘

(soluble) GI (LU) 2 x 10’ 7 9 X 1 0 - ‘

(insoluble) GI (LLI) 2 x 10"7 9 X 1 0 ' *

(soluble) GI (LU) 3 x 10‘ 7 1 0 ‘ !


2 x 10“7io->

»N<i (soluble) GI (LU) Uver 4 .5

4 x 10“7 4 x 10“7

2 X 1 0 ' J


2 .8 2 X 10“72 X 10-J

69


TABLE A l-H a (cont.)




O ld)


QiCi/cm5)


(ingestion) (pCi/cm*)

«N d (soluble) GI (LLI) 2 X 1 0 'f 8 x 1 0 "’

(insoluble) GI (ULI) 10"« 8 x 10" ’

]: i pm (soluble) GI (LLI) Bone 31 6 X 1 0 " '

6 x 10‘ J


12 10"76 x 10"*

“ l Pm (soluble) GI (LLI) 3 X lO '7 1 0 "’

(insoluble) GI (LLI) 2 X 1 0 '7 lO "1

« S m (soluble) Bone GI (LLI)

9 .5 x 1 0 * * 7 X 1 0 - “ 2 X 10‘ ! 2 X lO 'J


0. 036 3 X 1 0 "102 X 1 0 "s

‘g Sm (soluble) GI (LLI) Bone 84 6 X 1 0 '1

0 .01


20 1 0 " ’0 .01

(soluble) GI (LLI) 5 X 1 0 - 7 2 X 1 0 -“

(insoluble) GI (LLI) 4 X 10‘ 7 2 X 1 0 " ’

ls*Eu63 (soluble) GI (LLI) 4 X 1 0 "7 2 X 10 "5(9 .2 h)

(insoluble) GI (LLI) 3 X 1 0 " 7 2 X 1 0 - ’

(13 yr)(soluble) GI (LLI)

Kidney 1 10"*2 X 1 0 "s


2 .5 2 X 1 0 " !

2 X 1 0 - ’

‘fjEu (soluble) GI (LLI) Kidney Bone

0. 33 4 .1

4 X 1 0 "’ 4 X 1 0 "’

6 X 10“*


0. 97 1 X 10_s6 X 10-*

*11=“ (soluble) GI (LLI) Kidney Bone

339

9 X 1 0 - '6 X 1 0 " 3


8 .8 1 X 1 0 " *

6 X 1 0 - ’

70


TA BLE A l-IIa . (cont.)




OiCi)


(jiCi/cm 8)


(ingestion) (jiCi/cm 3)

153,- . 64 (soluble) GI (LLI)

Bone 47 2 x 10"76 X 10-*


8 .5 9 x 10"*6 X 10"s

159 r-A„Gd (soluble) GI (LLI) 5 x 1 0 '7 2 X 10"3

(insoluble) GI (LLI) 4 x 10"T 2 X 1 0 's

160 T-W, 65 10 • (soluble) GI (LLI) Bone Kidney Total body

10 10"710“710‘ 7

i o - ’


1 ,7 3 x 10 '*1 0 '1

“> (soluble) GI (ULI) 3 x 10“® 0.01

(insoluble) GI (ULI) 2 X 10“6 0 .01

> y (soluble) GI (LLI) 2 X 1 0 '7 1 0-’

(insoluble) GI (LLI) 2 x 10"7 1 0 '1

■Sho (soluble) GI (LLI) 2 x 1 0 '7 9 x 10-*

(insoluble) GI (LLI) 2 x 10"7 9 x 10_<

(soluble) GI (LU) 6 x 1 0 '7 3 X 1 0 '3


3 .8 4 x lO"73 X 10"’

m Er68 (soluble) GI (ULI) 7 x 10’ 7 3 X 10-1

(insoluble) GI (ULI) 6 x 10-» 3 X 1 0 '1

170,-» Tm (soluble) GI (LLI)

Bone 6 .5 4 x 10-81 0 '1


2 .5 3 x 10“*i o - s

171-r„ 69 (soluble) GI (LLI)

Bone 73 1 0 '70 .01


28 2 x 10“70. 01

175Vk70™ (soluble) GI (LLI) 7 x 1 0 '7 3 X 10"’

(insoluble) GI (LU) 6 x 1 0 '7 3 X 10"’

71





permissibleDerived air

concentration


dose rate (MCi)

(^Ci/cm3)(pCi/cm*)

n L“ (soluble) GI (LLI) 6 x 10“7 3 x 10"s

(insoluble) GI (LU) Lung 5 .2

5 X 1 0"' 3 x 10"s

(soluble) GI (LLI) Spleen 0. 50 4 X 1 0"'

2 x 10"3


2 .9 7 X 10"!2 x 1 0 's

» T . (soluble) GI (LLI) Liver 2 .6 4 X 1 0 " '

10"*


1. 5 2 X 1 0 " '10-s

1,1 W74 " (soluble) GI (LLI) 2 X 10"‘ 0 .01


9 .6 1 0 ' '0 .01

‘P.w (soluble) GI (LLI) 8 X 1 0 " ' 4 X 10-3


6 1 0 " '3 x 10~3

(soluble) GI (LLI) 4 X 10- ' 2 x 10"3

(insoluble) GI (LLI) 3 X 1 0 " ' 2 x 10' 3

(soluble) GI (LLI) 0 .0 2Total body 82 3 X 1 0 '5 0 .0 2


8 .4 2 X 1 0 " '8 x 10-3

‘“ Re (soluble) GI (LLI) 6 X 1 0 " ' 3 x 10“ 3

(insoluble) GI (LU) 2 X 1 0 " ' 10‘ s

” Re (soluble) GI (LLI) 0. 07Skin 280 9 X 1 0 '6


70 5 X 1 0 - '0. 04

™Re (soluble) GI (LU) 4 X 1 0 " ' 2 x 10“ 3

(insoluble) GI (LU) 2 X 1 0 - ' 9 x 10“ 4

■So* (soluble) GI (LLI) 5 X 1 0 - ' 2 x 1 0 -3


2 .9 S X i o - ‘2 x 10“3

72






(fiCi)


(fiCi/cm5)


(ingestion) GiCi/cm3)

(soluble) GI (LU) 2 x 10" 5 0. 07


6 .4 9 x 10“®0. 07

™ 0s (soluble) GI (LLI) 1 0 "6 5 x 1 0 "3


7 4 x 10’ 75 x 10~3

(soluble) GI (LLI) 4 x 10“7 2 x 1 0 "3

(insoluble) GI (LU) 3 x 1 0 '7 2 x 1 0 "3

> (soluble) GI (LLI) 10”® 6 x 1 0 "3


5 .2 4 x 1 0 "75 x 10’ 3

> (soluble) GI (LLI) 1 0 'sKidneySpleen

0 .5 10” T 1 0 '7


1 .4 3 x 1 0 "810-3

m ii77 (soluble) GI (LLI) 2 x 10"7 1 0 " !

(insoluble) GI (LLI) 2 x 10”7 9 x 1 0 "4

191 pt 78 (soluble) GI (LLI) 8 x 10” 7 4 x 10"s

(insoluble) GI (LLI) 6 x 10”T 3 x 10-S

m ptm (soluble) GI (LU) 7 x 10"6 0. 03

(insoluble) GI (LU) ' Lung 26

5 x 10"6 0. 03

i«P t78 (soluble) Kidney 18 1 0 '6 0. 03


44 3 x 10"70 .0 5

197p,m78 (soluble) GI (ULI) 6 x 10"6 0 .0 3

(insoluble) GI (ULI) 5 x 10"6 0 .0 3

(soluble) GI (LLI) 8 x 10' 7 4 x 1 0 '3

(insoluble) GI (LLI) 6 x 10* 7 3 x 1 0 "3

I9> (soluble) GI (LLI) 10"fi 5 x 10"3


4 6 x 1 0 "74 x 10“3

73






GiCi)


(pCi/cm3)


(ingestion) (jiCi/cms )

(soluble) GI (LLI) 3 x 10-7 2 x 10“s

(insoluble) GI (LLI) 2 x 10‘7 10"3

T»Au (soluble) GI (LLI) 10’6 5 x 10“3

(insoluble) GI (LLI) 8 x 10"7 4 x 10"3

> g ra (soluble) Kidney 1 .4 7 x 10"7 6 x 10’ 3

(insoluble) GI (LLI) 8 x 10“7 5 X 10"s

»Hg (soluble) Kidney 5 .9 10-6 9 x 10‘ 3

(insoluble) GI (LLI) 3 X lO"6 0. 01

> 8 (soluble) Kidney 1 .7 7 x 10-8 5 x 1Q~*


4 .9 10-73 x 10“ s

200 'pi 81 11 (soluble) GI (LLI) 3 x 10"6 0. 01

(insoluble) GI (LLI) 10“* 7 X 10"3

201-pi 81 11 (soluble) GI (LLI) 2 X 10"6 9 x 10“3

(insoluble) GI (LU) 9 x 1 0 '7 5 x 10’ 3

202 rpl 81 11 (soluble) GI (LLI) 8 X 1 0 '7 4 x 10_S


3 .1 2 x 10‘ 72 x 10“3

™T1 (soluble) GI (LLI) 3 x 10“sKidney 1 6 x 10"7


3 .4 3 x 10"»2 X 10“9

«»pb (soluble) GI (LU) 3 x lO "6 0. 01

(insoluble) GI (LLI) 2 x 1 0 -6 0 .01

™pb (soluble) Kidney Total body

0.025 10"10 4 x lO -6 4 X 10”6


0. 034 2 x 10-1®5 x 10"s

! yn> (soluble) Kidney GI (LLI)

0 .0031 2 x 10' 8 6 x 10-4 6 x 10“4


0. 010 2 x 10“85 x 10“4

> (soluble) GI (LLI) 2 x 10“7 1 0 "3Kidney 0 .4 3 2 x 10“7


10~710-s

74






OiCi)


(pCi/cm3)



207 in 8$ (soluble) GI (LLI) Kidney 0 . 7 6 2 x 10-7

2 x 1 0 *8


1 .9 1 0 '82 x 10‘ s

(soluble) GI (LLI) Kidney 0 . 0 1 3 6 x 10*9

1 0 *3


0 . 0 3 2 6 x 1 0 -910-3

T j B i (soluble) GI (S) Kidney 0 .0 0 3 0 10-7

0 .01

(insoluble) Lung GI (S)

0. 010 2 X 1 0 " 7

0. 01

(soluble) Spleen 0. 002 5 x l O - 10 2 x 10-sKidney 0 . 0 0 4 5 5 x 1 0 '10 2 x 10‘ s


0 . 0 1 5 . 2 x 1 0 '108 x 10* 4

(soluble) Thyroid 0 .0 0 0 4 7 7 x 10*9 5 x 10*sOvary 0.000031 7 x lO "9 5 x 1 0 '5

(insoluble) Lung GI (ULI)

0.11 3 x 1 0 "82 x 1 0 "s

! ! > a Lung 3 x 10*7a

Lung 3 x 1 0 *8 a

(soluble) Bone 0. 039 2 X 1 0 " 9 2 x 10‘ 5


3 x 10"9 2 x 10‘ 1010*4

(soluble) Bone 0.039 5 x 10*9 7 x 1 0 "5


0.0029 7 x 1 0 '102 x 1 0 "4

2!lRa (soluble) Bone 0 .1 3 x 10M1 4 x 10*7

(insoluble) GI (LLI) 2 x 10“7 9 x 10~*

(soluble) Bone 0 . 0 5 8 7 x 1 0 ' u 8 x 1 0 ' 7


0 . 0 0 5 2 4 x 1 0 * 11

7 x 1 0 " «

3 The daughter elements of 120Rn and m Rn are assumed to be present to the extent that they occur in unfiltered air.For all other radionuclides, the daughter elements are not considered as part of the intake; i f daughter elements arepresent, they must be considered on the basis of the rules for mixtures.

75






O iC i)


0iCi/cm3)


(ingestion) O iC i/cm3 )

m A c89 AC (soluble) Bone 0.011 2 X 1 0 " ‘ ! 6 x 10_s


0 .0036 3 X l O ' 11

9 x 10‘ 3

228 . m a<: (soluble) GI (ULI)

BoneLiver

0.011 0. 026 8 X 1 0 ' '

3 x 10-3

(insoluble) Lung GI (ULI)

0. 0052 2 X 10"«

3 x 1 0 '3

227 - so T h (soluble) GI (LLI)

Bone0. 03 0 . 011 3 X l O ' 1"

5 x 10‘ 4

(Insoluble) Lung GI (LLI)

0. 0036 2 X 1 0 ‘ "

5 x 1 0 '4

228 ~ 90 T h (soluble) Bone 0.011 9 X 1 0 ' 1! 2 x 10’ 4


3. 5 x 10-3 6 X 1 0 - l !

4 x 1 0 '4

230-ru90 T n (soluble) Bone 0.046 2 X 1 0 ' 1! 5 x 1 0 -s


0. 017 i o - “9 x 10*4

231 r~90 Th (soluble) GI (LLI) 1 0 " ‘ 7 x 10-s

(insoluble) GI (LLI) i o - f 7 x 10_J

Th a 90 1,1 (soluble) Bone 0. 041 2 X 1 0 - i ! a 5 x 10*5


0. 018 i o - “1 0 "s

234 m, (soluble) GI (LLI) 5 x 1 0 '4Bone 2 .4 6 X 1 0 ->


0. 93 3 X 1 0 - '

5 x 10“4

,i jr h (natural)3 (soluble) Bone 2 X 1 0 " 1 Ia 3 x 1 0 "5

(insoluble) Lung GI (I I I )

4 X 1 0 " ‘ !

3 x 10’ 4

Provisional values for zaTh and natural thorium. Although calculations and animal experiments suggest that natural thorium, if injected intravenously, is perhaps as hazardous as plutonium and therefore the above-listed values are indicated, experience to date has suggested that in industry the hazard of natural thorium is not much greater than that of natural uranium. Therefore, pending further investigation, the value of (DAC)a = 3 x 10’ 11 jiCi/cm3 for occupational exposure (40 h/week) is recommended as a provisional level, permissible for exposure to inhaled natural thorium or 232Th. However, the above values are listed to indicate the possibility that further evidence may require lower values and to urge especially that exposure levels for these radionuclides be kept as low as is operationally readily achievable. It may be possible to show that similar considerations apply to other inhaled long- lived thorium isotopes under conditions in which the physical characteristics of the airborne particulates are much the same as in the case of natural thorium and where there is a large amount of airborne m aterial serving as an effective carrier for the thorium.

76






GiCi)


OiCi/cm3)



230 Pa9 1 K a (soluble) GI (LLI) Bone 0. 034 2 x 1 0 '9

7 x 1 0 '3


0 .014 8 x 10“107 x 10-3

231 Pa 91 ™ (soluble) Bone 0.015 10“1Z 3 x 1 0 '5


0 .016 lO "108 X lO-4

233 Pa91 (soluble) GI (LLI) Kidney 1 .7 6 x 10“7

4 x 10’ 3


4 .7 2 x 1 0 "73 x 10’ 3

2 3 0 ,, a 92 (soluble) Kidney 0. 00072 3 x 10-10 7 x 10_s


0. 0024 1 0 -io

10"*

(soluble) Bone 0 .0091 i o -10 2 X 10’ s


0. 004 3 x 10-118 x 10“*

■ £ u a (soluble) Bone 0. 044 5 x 1 0 '10 1 0 '4


0 .017 lO-io9 x 1 0 '4

2s«n a92 U (soluble) Bone 0. 046 6 x 10’ 10 10“4


0.017 10*io9 x 10"4

i s s y a 92 u (soluble) Kidney

Bone1. 9 x 10‘ 3

0. 0485 x 1 0 - ‘<» lO "4

10“4


0 .018 10“io8 x 10“4

2S6u a92 U (soluble) Bone 0. 047 6 x 1 0 "10 10“4


0 .018 lO-io10‘ 3

2S*u a92 u (soluble) Kidney 3 .1 x 10"4 7 x 10“ 11 2 x 10“s


0 .0 2 . 10“io1 0 '3

aBecause of the chem ical toxicity of natural uranium, m U, 2S6U, and 2S5U in soluble form, inhalation of uranium of any isotopic composition should not exceed 2. 5 mg of soluble uranium per day; ingestion of soluble uranium should not exceed 150 mg per day.

77






(MCi)


(MCi/cm3)


(ingestion) (MCi/cms)

92U (natural)a (soluble) Kidney 7 x 10““ 2 x 10-5


6 x 1 0 "u5 x 1 0 "4

!" U + !“ Np (soluble) GI (LLI) 2 x 10’ 7 10-3

(insoluble) GI (LLI) 2 x 10’ 7 10~s

T . N P (soluble) Bone 0. 044 4 x 10-12 9 x 10-5


0.017 lO-io9 x 10“*

* > P (soluble) GI (LLI) 8 x 10’ 7 4 X 10“ s

(insoluble) GI (LLI) 7 x 10-7 4 x 10-s

!|fpu (soluble) Bone 0 .039 2 x 10-“ 10“*


0 .015 3 x 1 0 '118 x 10-4

» » P U (soluble) Bone 0. 041 2 x 10"12 10’ *

■ (insoluble) Lung GI (LLI)

0 .016 4 x 10-n8 x 10’ *

“ P» (soluble) Bone 0. 041 2 x 10"12 10’ 4


0. 016 4 x 10-n8 x 10’ 4

“ >Pu (soluble) Bone 0 .7 8 9 x 10’ 11 7 x 10-3


16 4 x 10"*0. 04

14! p 94 rU (soluble) Bone 0. 044 2 x 10"12 10~4


0.016 4 x 10’ u9 x 10‘ 4

“ Pu (soluble) GI (ULI) 2 x 10"« 0 .01

(insoluble) GI (ULI) 2 x 10 -« 0 .01

M p " (soluble) Bone 0. 045 2 x 10‘ 12 1 0 '4


0. 017 3 x 10_u3 x 10"4

Because of the chem ical toxicity of natural uranium, 238U, 236U, and 235U in soluble form, inhalation of uranium of any isotopic composition should not exceed 2 .5 mg of soluble uranium per day; ingestion of soluble uranium should not exceed 150 mg per day.

78






OiCi)


(fiCi/cm3)


(ingestion) QiCi/cms)

“ Am (soluble) KidneyBone

0. 0044 0. 039

6 x 10‘ 12 6 x 10"1Z

10"410’ 4


0 .015 1 0"108 x 10’ 4

“ A m " (soluble) BoneKidney

0. 036 6 X 10‘ 12 6 x 10”12

10’ 410‘ 4


0 .037 3 x 10’ io9 x 10"4

!«A m (soluble) GI (U I) Liver

0 .098 0. 023 4 x 10-*

4 x 10’ 3


0. 037 5 x 1 0 "84 x 10"s

“ A " (soluble) GI (SI)BoneKidney

0.044 0. 044

4 x 10‘ 6 4 x 10"®

0 .1

(insoluble) Lung GI (SI)

0 .5 2 2 x 10"s 2 x 10’ 5 0 .1

(soluble) GI (LU) Liver 0 .0 1 8 10"10

7 x 10-4


0 .013 2 x 10-107 x 10”4

“ Cm (soluble) Bone 0. 037 6 x 10’ 12 10"4


0. 014 10-107 x 10’ 4

24496 C m (soluble) Bone 0. 037 9 x 1 0 '12 2 x 10‘ 4


0 .0 1 4 lO -io

8 x 10"4

“ O n (soluble) Bone 0. 039 5 x 10‘ 1! 10-4


0. 015 IQ * 1®

8 x 10“4

* C m (soluble) Bone 0. 039 5 x 10-12 1 0 "4


0. 015 lO’ 108 x 10"4

! !iC m (soluble) Bone 0. 041 S x 10"12 1 0 ' 4


0. 015 lO -io

6 x 10"4

!“ Cm (soluble) Bone 0. 0048 6 x 1 0 '13 4 x 10-s


0 ,0018 1 0 " 11

4 x 10"s

79



Radionuclide C ritical otgan



(MCi)


0iCi/cm s)


(ingestion) (pCi/cms)

(soluble) GI(S)Bone 0 . 4 1

1 0 ' 5

10-s0 . 0 6

(insoluble) GI(S) 10-s 0 . 06

> k (soluble) GI (LLI) Bone 0 . 5 5 9 x 1 0 " 10

0 . 0 2


1 2 1 0 -70 . 0 2

> k (soluble) GI (ULI) Bone 0 . 0 3 8 1 0 " 7

6 x 1 0 -3

(insoluble) GI (UU) i o " ‘ 6 x 1 0 -3

» Cf (soluble) Bone 0 .0 3 7 2 X 1 0 ' 1! io -*


0 . 0 1 4 1 0 " “

7 x 1 0 - 4

ZSOpf98 (soluble) Bone 0 . 0 3 5 5 X « r 1! 4 x lO"4


0 . 0 1 4 1 0 - “

7 x 1 0 - *

251 c f 98 (soluble) Bone 0 . 0 3 8 2 X 1 0 ' 1! 10-4


0 . 0 1 4 1 0 " 1"

8 x 1 0 ' 4

252 Cf98 (soluble) GI (LLI) Bone 0.01 6 X 1 0 " ‘!

2 x 1 0 ' 4

Spontaneous fission(insoluble)

Lung GI (LLI)

0 . 0 0 4 3 X 1 0 ' 11

2 x 1 0 ’ *

80


T A B L E A l - I I b . D E R IV E D C O N C E N T R A T IO N L IM IT S O FN A T U R A L T H O R IU M AND N A T U R A L O R D E P L E T E D U RA N IU MF O R O C C U P A T IO N A L E X P O S U R E (40 h/w eek)

Rad ion uclid eC r it ic a l

organ

Organ co n ten t g iv in g

m axim um

p erm issib le dose ra te a

(# g )c

D erived air c o n cen tra tio n

(M g/cm3) c

D erived w ater c o n cen tra tio n b

(in g e stio n )

(M g/cm3) c

T h (n a tu ra l)0 (so lu b le) Bone 8 . 0 x 104 1 .4 8 x 1 (T S 3 .4 5 x 102

(in so lu b le)Lung GI (LLI)

3 .7 2 x 1 0 '52 .6 6 x 1 0 3

U (natural)**1 e (so lu b le) K idney 9 .2 x 102 2 . 2 x 1 0 "4 5 .1 1 X 10

(in so lu b le)Lung GI (LLI)

1 .9 2 x 1 0 '41 .4 6 x 1 0 3

a E xcep t for so lu b le uranium , w here th e kidney burden is based on c h e m ic a l to x ic ity , w hich is m o re lim itin g .

k T h e derived w ater co n cen tra tio n values should not b e in terp reted to m ean th a t th e w orker is l ia b le , a t h is w orking p la c e , to drink w ater co n ta in in g ra d io a c tiv ity a t h igh er co n cen tra tio n s than in p u b lic w ater supplies.

c O ne gram o f natural thorium co n ta in s 0 .1 1 jiC i 232 T h , 0 .1 1 /iCi 228T h and various am ounts o f 227T h , 231Th and 234T h , depending on th e r e la t iv e abundance o f 232T h and n atural uranium in th e ore and th e a g e a fter processing . T h e values for natural thorium are p rov ision al. A lthough c a lc u la tio n s and a n im a l exp erim en ts suggest th a t n atu ra l thoriu m , i f in je c te d intrav enou sly , is perhaps as hazardous as p lutonium and th ere fo re th e a b o v e -lis te d values a re in d ica ted , e x p e rie n ce to d ate has suggested th at in industry th e hazard o f natural thorium is not m uch g rea te r than th at o f n atu ra l uranium . T h erefo re , pending further in v estig a tio n , a DAC o f 2 . 6 x 1 0 " 4 jig/ cm 3 n atu ra l thorium fo r ra d ia tio n workers during w orking hours is recom m en d ed as a p rovision al le v e l.

^ One gram o f natural uranium and depleted uranium co n ta in s 0 .3 3 fiC i 238U , up to 0 .3 3 jxCi 234U and up to 0 .0 1 5 3 jiC i 235U.

e Becau se o f th e c h e m ic a l to x ic ity o f natural uranium , 238U, 236U, and 235U in so luble form , in h a la tio n o f uranium of any iso to p ic co m p o sitio n should not e x c e e d 2 . 5 m g o f so lu b le uranium per day; in gestion o f so lu b le uranium should not e x c e e d 15 0 m g per day.

81


T A B L E A l - I I c . D E R IV E D C O N C E N T R A T IO N L IM IT S O FP A R T IA L L Y UNKNOWN M IX T U R E S O F R A D IO N U C L ID E S INW A T E R F O R O C C U P A T IO N A L E X P O S U R E (40 h/w eek)

L im itation s

D erived water co n cen tra tio n a

(in g estio n )(|i C i/ cm 3)

None o f the rad ion uclid es 90Sr, 129I, 210Pb, 210Po, 223Ra, 226Ra, 2Z8Ra, 227A c, 231Pa, 232U , U (n atu ra l), Th (n a tu ra l), 248C m , 254C f, 256Fm present 9 x 1 0 ' 5

None o f th e rad ionuclides 129I , 210Pb, 226Ra, 228Ra, 254C f present 6 x 1 0 ' 5

N eith er 226Ra nor 228Ra present 3 x 1 0 ' 6

No in fo rm atio n is a v a ila b le on the com p osition o f the m ixture 3 x 1 0 ' 7

aT h e derived w ater co n cen tra tio n values should not be in terp reted to m ean th at the worker is l ia b le , at his w orking p la c e , to drink w ater co n ta in in g ra d io a ctiv ity at h igh er co n cen tra tio n s than in p u b lic w ater supplies.

82


T A B L E A l- I I d . D E R IV E D C O N C E N T R A T IO N L IM IT S O FP A R T IA L L Y UNKNOWN M IX T U R E S O F R A D IO N U C L ID E S INA IR F O R O C C U P A T IO N A L E X P O S U R E (40 h/w eek)

L im itation s

D erived air co n cen tra tio n

(/iCi/cm3 )

No a -e m it t in g rad ion uclides and none o f the g -e m itt in g rad ion uclides 90Sr, 1Z9I, 210Pb, 227A c, ZZ8Ra, 230Pa, 241 Pu, 249Bk present 3 x 1 0 ' 9

No c«-em ittin g rad ionuclides and none o f the 6 -e m itt in g rad ionuclides 210Pb, 227A c, 228Ra, 241 Pu present 3 x 1 0 " 10

No a -e m it t in g rad ionuclides and no fi-e m ittin g rad io n u clid e 227A c present 3 x 1 0 " 11

None o f the rad ionuclides 227A c, 230 T h , 231Pa,Z22T h i 238 p U( 239pU( Z40pUi 242pu> 244pU( 2 4 8 ^

Z49C f, 251C f present 3 X 1 0 " 12

None o f th e ra d io n u c lid e s231 Pa, 239 Pu, 240Pu, 242 Pu, 244 Pu, 248 C m , 249C f, 251 C f present 2 x 1 0 " 12

248 C m not present 7 x 1 0 " 13

No in form ation is a v a ila b le on th e com p osition o f the m ixture 1 0 " 12

83


APPENDIX 2

MAXIMUM PERM ISSIBLE LEVELS FOR SURFACE CONTAMINATION

A 2-1. INTRODUCTION

The decontamination procedures for contaminated surfaces should be continued until the residual contamination of the surface is reduced to an acceptable level. Unfortunately, there are no internationally agreed perm issible levels for surface contamination, the latter depending on many variables. It is impossible to express a simple quantitative relationship between the levels of radioactivity on various surfaces and the resulting radiation doses to personnel. Actual radiation doses, particularly as a result of inhalation and ingestion, will depend on the nature of the radioactive m aterial, working conditions, personal habits of the w orkers, fraction of 'free ' and 'fixed1 radioactive m aterial, etc.The doses will thus depend on the circum stances associated with the contamination. These circum stances can vary greatly from one working area to another and therefore the perm issible surface contamination levels may be influenced by:

(a) The nature and quantity of the contaminating radionuclide;(b) The nature of the contaminated surface, e.g. its structure and

condition;(c) Environmental factors, e.g. degree of occupancy, kind of work

performed, ventilation, humidity;(d) Personnel contamination control m easures provided in the

working area, e.g . protective clothing, respiratory protection, and others;

(e) Food habits of workers; in special circum stances, ingestion may be the critica l pathway instead of inhalation.

Maximum perm issible surface contamination levels are , however, of value in the monitoring of the working place and serve as an index of the degree of control for operations with radioactive m aterial. Satisfactory results of surface contamination monitoring will usually indicate that the overall contamination control measures are sufficiently good to make routine air monitoring unnecessary. However, this conclusion must be used with care . There are conditions where it is not sufficient to rely on surface contamination monitoring, e.g. when operating with gases or vapours, or alpha em itters of very high toxicity such as plutonium, or where the measurement of surface contamination is difficult for technical reasons.

The results of measurements of surface contamination cannot be related quantitatively to the body content without gross sim plification.

84


In addition, most monitoring instruments available are m erely qualitative, since they cannot identify the radionuclide, m easure the activity actually on the surface, or otherwise determine the extent of the hazard to persons.

Another factor to be considered is the common need to establish contamination control procedures for considerations other than personnel protection, e .g ., counting rooms often require far more stringent contamination controls than would normally be necessary for personnel protection purposes.

The following data are given as examples of various maximum perm issible levels for surface contamination used in different countries.

A 2 -2 . FR A N C E

R ad iotoxicity o f rad ionuclid es

Equipm ent and w orking p lacesC loth ing Skin

in ’in a c t iv e ' areas in ’a c t iv e ’ areas

Very high

a - e m itters :1 0 " 5 p C i/ c m 2

6 -e m itte rs : 1 0 -4 fiC i/ c m 2

oc-em itters:

1 0 - 4 / iC i/cm 2

6 -e m itte rs : 1 0 -3 ^ C i/ c m 2

ce-em itters: 1 0 _s ^ iC i/cm 2

fi-e m itte rs :1 0 " 4 p C i/ cm 2

a -e m itte rs :5 x 1 0 -6 jiC i/ c m 2

8 -e m itte rs :5 x 1 0 ” 5 p C i/ cm 2

H igh I M edium I Low

1 0 ‘ 4 jiC i/ c m 2 1 0 “3 p C i/ c m 2 1 0 -4 | iC i/cm 2 5 x 1 0 “5 (iC i/ cm 2

R e fere n ce : N ote No. 1 7 2 , M ay 1 9 5 6 , issued by th e French A to m ic Energy C om m ission .N o te : T h e c la ss if ic a tio n o f ra d io to x ic itie s o f rad ion uclides is s im ila r to th a t g iv en in this M anual.

85


A 2 - 3 . PO LA N D

Ty p e o f surfaceA lpha

co n tam in atio n

Q iC i/ cm 2)

B eta co n ta m in a tio n a

( jiC i/ cm *)

W orking surfaces in rad ioisotope lab o rato ries o f Ty p e A

1G~4 1 0 '3

W orking surfaces in rad ioisotope lab o rato ries o f types B and C

10-5 1 0 '4

S u rfaces o f floors, w alls, furniture and oth er things w ithin rad ioisotope lab oratories

5 x 1 0 " sb 5 x 1 0 " 5b

S p e c ia l c lo th es and tow els, surfaces o f g lov es and sp e c ia l shoes used in rad io isotop e lab o rato ries

1 0 -s 1 0 ' 4

S p e c ia l underwear used in rad ioisotope lab o rato ries

i o - « b i o - sb

aFor 3H, co n ta m in a tio n le v e ls m ay be ten tim es h igher,

k T h ese values re fer to fixed co n ta m in a tio n ; a ll 'free* co n tam in atio n should b e co m p le te ly rem oved .

N o te : T h e above p erm issib le le v e ls are on the av erag e for surfaces w hich do not e x c e e d 3 0 0 c m 2.

86


A 2 - 4 . U N IT E D KIN GDO M

Ty p e o f surfaceD erived w orking lim its

(fiC i/ cm 2)

S u rfaces o f in teriors and con ten ts o f to ta l and p a rtia l en closu res (e . g . g lov e box and fum e hood)

M inim u m th a t is reasonably p ra c tic a b le

S u rfaces o f a c tiv e areas (exclu d in g in terio r and con ten ts o f to ta l and p a rtia l enclosu res) and apparatus, equ ip m en t (in clu d in g personal p ro te c tiv e eq u ip m en t), m a teria ls and a rtic le s w ithin a c t iv e areas

A lpha e m ittersA ll other

rad ionuclidesT o x ic ity T o x ic ity group 1 groups 2 - 4

oi o 1 0 '3

S u rfaces o f th e body 10-5 10-5 1 0 "4

A ll o th er su rfaces, e . g . in a c tiv e areas, personal c lo th in g , h o sp ita l bedding 10 ”5 1 0 - 4 i o - 4

R eferen ce : C ode o f P ra c tice for the P ro tectio n o f Persons Exposed to Io n iz in g R ad iation in Research and T ra in in g , H er M a jes ty ’s S ta tio n ery O ff ic e (1 9 6 8 ),

N o te : T h e results o f m easurem ents m ay b e averaged over areas as stated below : In an im ate surfaces: 30 0 c m 2 (1 0 0 0 c m 2 for floors, w alls and ce ilin g s)Su rfaces o f th e body: 100 c m 2 (hands: over the w hole area o f the hand, taken

no m in ally as 300 c m 2).

87


A 2-5 . UNITED STA TES OF AMERICA

The National Bureau of Standards Handbook 92, "Safe Handling of Radioactive M aterial", issued 9 March 1964, sets forth recommendations regarding unconditional release of surface-contaminated artic les . Some of the relevant paragraphs are quoted below.

"5 .6 . Control of contaminated articles

"W herever radionuclides are used, clothing, tools, and equipment may become contaminated. These contaminated articles should be controlled to prevent spread of radioactive m aterials to clean areas or even to public areas outside of the installation. The problems involved depend on the magnitude of the program and the experience of the individual involved.

"In general, these items fall into two c lasses , namely: (1) those items which remain in a controlled area and are re-used, and (2) those items which are no longer needed and can be safely released, after decontamination, for use in other work.

"a . Controlled area

"Contamination levels in a controlled area are usually subjected to indirect checks such as measurement of a ir concentrations, frequent measurements of personnel contamination, e tc ., so that hazards induced by the presence of the contaminated article become a part of the overall program of control. F o r this reason, controls on the levels of contamination on articles used in the laboratory can be set by considerations of overall hazard and the protection program and specific lim its are not needed.

"Equipment to be transferred from one controlled area to another should be thoroughly surveyed before moving and, if the level is higher than the general level in the new area, decontamination should be carried out. Equipment which is shown to be contaminated, or which has inaccessible parts and has been in a controlled area, should be marked with the radiation symbol. If it is to be stored or used by another group, it should also bear a description of the kind and level of contamination and the date of the survey. If the external radiation level exceeds one mrem per hour or if the contaminant is such that an individual might accidentally receive from it more than one-tenth of the maximum perm issible body burden, then additional safeguards should be applied. These might include an outer container or shield or storage in a locked enclosure.

"b . Conditional release from control

"A conditional release procedure may provide suitable control of articles such as heavy mobile equipment which do not leave the installation, or of areas or fixed equipment not entirely free of contamination but causing insignificant hazard. Requirements for conditional release should include the following:

88


"a . The equipment is not contaminated to a level where it is a radiation hazard itself.

"b . The intended use presents no radiation hazard to informed u sers, " c . Regulations for controlling the radiation or contamination are

securely attached to the equipment in a prominent place."d. Property inventory records are maintained for each item listing

its "home" location, radiation status, person responsible for control, and date of latest inventory.

" c . Unconditional re lease from control

"If articles are to be released from the controlled area for use in uncontaminated areas, surface contamination must not exceed acceptable levels. The perm issible contamination depends on such factors as the relative hazard of the radionuclides involved, including both the external radiation and the uptake in the body; the degree of fixation of the contaminant; the mobility of the article involved; the accessibility of the contamination in the normal use of the article ; and the possible in terference with sensitive radiation measurements.

"M easurem ents of surface contamination are usually expressed in term s of the response of the instrument used rather than in absolute units because of the unknown depths of penetration of the m aterial into the surface. Suggested levels of "significant contamination", below which an item can be released from the controlled area, are given in Table 6.

"T A B L E 6. SU G G ESTED L E V E L S O F 'SIG N IFICA N T CONTAMINATION'

M easuring instrum entsL ev e l for nuclides

in groups1 and 2 a 3 and 4 a

G eiger coun ter (fi, y )^ 100 cpm 100 cpm

Io n iz a tio n ch am b er 0 .1 mrad/hr 1 mrad/hr

A lpha counter 1 d / m / cm 2 10 d / m / cm 2

a T a b le 2 .k F la t p la te a re a o f two square in .

"A "wipe" or "sm ear" test is valuable for detecting the presence of loose contamination. In this test, the object is wiped with a piece of cloth, paper, or sticky tape, and the m aterial measured on a sensitive device which will detect the radiation emitted (see section 5.7). The degree of fixation of contamination and the mobility of the article are particularly important.

89


"Requirem ents for unconditional release should include the following:

"a . All accessible surfaces are free of significant contamination, as determined by surveys with sensitive alpha, beta, or gamma monitoring instrum ents, appropriate to the nuclides that have been used.

"b . It must be reasonable to presume that inaccessible surfaces are uncontaminated, on the basis of two prem ises: that, without being cleaned, accessible surfaces are free of significant contamination; and that no radioactive m aterials could have contaminated the inaccessible surfaces without having contaminated the outer surfaces as well.

" c . The m aterials of which the item is made are such as would not be likely to occlude radioactive m aterials.

"d. Wipe or sm ear tests indicate no detectable loose contamination and there is reasonable assurance that any fixed contamination will not become loose and subject to spread at some later date."

A 2 -6 . UNION O F SO V IE T SO CIA LIST R E P U B L IC S

M axim um p e rm is s ib le le v e ls fo r su r fa ce contam ination (p a rtic le s/ cm 2 • min)

A lpha e m ittersTy p e o f surface

H ighly to x ic a M iscellan eo u sB e ta em itters

In tegum en t

Su rfaces o f w orking areas:

5 5 100

(1 ) W here s ta ff is continuously present

10 4 0 2 000

(2 ) W here s ta ff is p erio d ica lly p resent (second zone in th e th re e -z o n e system o f c la ss ific a tio n )

100 4 0 0 8000

Transfer and transport systems ̂ 10 . 10 100

A lp ha e m itters , th e averag e perm issible c o n cen tra tio n o f w hich in the a ir o f working areas is less than 2 x 1 0 " 15 C i/ litre , are c a lle d h ighly to x ic ,

k In th e c a se o f g a m m a e m itte rs , th e dose ra te a t a d is ta n ce o f 0 .1 m from th e surface o f transfer and transport system s should not e x c e e d 0 .1 mR/h.

(Approved by th e C h ie f Pu b lic H ealth Inspector o f the S o v ie t U nion, 2 5 August 1969 ,N o. 8 2 1 - A - 6 9 . )

90


A 2 -7 . S W IT Z E R L A N D

M axim um p e rm is s ib le le v e ls fo r s u r fa c e contam ination OuCi/100 cm 2 )

Equipm ent and w orking p la ce s

C on tro lled area N o n -co n tro lled area C lothes Skin

A lpha em itters 1 0 - 2 1 0 " 3 1 0 ‘ 3 5 x l t r 4

B eta e m itters 1 0 _1 1 0 "2 1 0 ' 2 5 x 1 0 "3

91


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INDIA Oxford Book and Stationery Comp., 17, Park Street, Calcutta 16 ISRAEL Heiliger and Co., 3, Nathan Strauss Str., Jerusalem ITALY Agenzia Editoriale Commissionaria, A.E.I.O.U., Via Meravigli 16,

1-20123 MilanJAPAN Maruzen Company, Ltd., P.O.Box 5050,100-31 Tokyo International

NETHERLANDS Martinus Nijhoff N.V., Lange Voorhout 9—11, P.O.Box 269, The Hague PAKISTAN Mirza Book Agency, 65, The Mall, P.O.Box 729, Lahore-3

POLAND Ars Polona, Centrala Handlu Zagranicznego, Krakowskie Przedmiescie 7, Warsaw

ROMANIA Cartimex, 3-5 13 Decembrie Street, P.O.Box 134-135, Bucarest SOUTH AFRICA Van Schaik’s Bookstore, P.O.Box 724, Pretoria

Universitas Books (Pty) Ltd., P.O.Box 1557, Pretoria SWEDEN C.E.Fritzes Kungl. Hovbokhandel, Fredsgatan 2, Stockholm 16

U.S.S.R. Mezhdunarodnaya Kniga, Smolenskaya-Sennaya 32-34, Moscow G-200 YUGOSLAVIA Jugoslovenska Knjiga, Terazije 27, Belgrade

Orders from countries where sales agents have not yet been appointed and requests for information should be addressed directly to:

Publishing Section,International Atomic Energy Agency,Karntner Ring 11, P.O.Box 590, A-1011 Vienna, Austria


IN T E R N A T IO N A L SUBJECT GROUP: IIA T O M IC EN ER G Y AG EN CY Nuclear Safety and Environmental Protection/Radiological SafetyV IE N N A , 1973 PRICE: U S $ 5 .0 0


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