radiation protection and overall optimisation of waste ... · other hazards$ “remediation...

Radiation protection and overall optimisation

of waste management after accidents

involving radioactive material

Graham Smith

GMS Abingdon Ltd

“Remediation Techniques and Strategies in Post-Accident Situations” IAEA 13 – 17 June 2016

I am not responsible for anything.

All comments are my own.

Our meeting is “Post-accident”$?

IAEA BSS, exposure situations:

� Emergency exposure situation

� Existing exposure situation, once the emergency is finished�

But:– When does the emergency start? (not this meeting�)

– How to transition from

• emergency to existing situation?

• existing situation to full recovery� return to normal?

– What about sites that are also affected by accidents and other events, not

just the accident?

– How to address uncertainties in basis science and assessment?

– How to link:

• radiation protection and management of other hazards?

• strategy for site remediation and strategy for waste management?

– What pre-planning can we do?


Transition emergency to existing situation$


Reference levels (etc.) are different in emergency and existing exposure

situations, so it is important to know when the emergency is ‘officially’

over.

Transistion: existing situation to normal


Some areas affected significantly by accidents AND by past planned releases, not according

to current standards, AND also by continuing planned operations.

Same with uranium mine legacies being re-opened..

Not just Mayak, e.g. accidents at Sellafield in the UK… numerous examples…

ICRP Task Groups 93 and 98, in progress

Objectives:

To describe and clarify the application of the Commission’s Recommendations on radiological protection of workers, the public, and environment to exposures resulting from sites contaminated due to past activities (TG98) and to nuclear or radiological accidents (TG93)

Either we have to explain why an existing situation has to be controlled differently for past activities (TG98) and for accidents (TG93), or we have to develop guidance which applies to both existing situations, irrespective of the cause.

Why not simply address the prevailing circumstances, including the {local} stakeholder issues?


Existing situation reference level range 1 – 20 mSv for the public,

whose garden is contaminated, but workers doing the remediation are

treated as if in planned situation. It can be hard to explain…

Other hazards$


The real risk here was that the building would fall down, but the

building surveyors would not go in to check building safety until the

area was “cleared of radiation”.

What about the chemicals used in the manufacturing process…?

A factor of three uncertainty$ is that

important?

� Given uncertainties in metabolism, exposure etc� a factor of

three uncertainty in the risk assessment is small

� A factor of three error in radius of area contaminated, changes

impact by an order of magnitude


Linking waste management and remediation

UK regulators responsible for site delicensing have issue:

Consultation on

Guidance on Requirements for Release of Nuclear Sites from Radioactive Substances Regulation, February 2016.

Leaving residual contamination and VLLW in underground structures on-site

may be simplest, safest and cheapest solution.

• This is now being considered as in-situ disposal, not management of

contaminated land.

• Disposal criteria apply, not contaminated land criteria.

• Safety assessment {experience and practice} is very different.

• Groundwater protection a special issue (EU Directive)

• Required to consider chemical, but guidance on how is limited�

• Heterogeneity is an issue.. As Mr Lively discussed


Series of international workshops

• Regulatory Supervision of Legacy Sites: from Recognition to Resolution Oslo 2015

• Radioecology and Assessment Research in Support of Regulatory Supervision of Protection of the Environment and Human Health at Legacy Sites, Barcelona 2014

• Emergency Preparedness and Response, Special Focus on Exercise and Training, Oslo, December 2013

• Coordination of Regulatory Arrangements for Nuclear and Radiation Emergency Preparedness and Response: Early and Later Phases Analysis, Washington, April 2013

Run by Norwegian radiation Protection Authority

Russian, US, European and Japan $plus IAEA, NEA and ICRP

very widespread participation


What was presented?

• Substantial information on history of accident and other legacy site

management and lessons learnt, giving many potentially helpful

recommendations. �State of the art techniques and experience of waste characterisation and

classification, including application after major accidents.

�Regulatory supervision: regulations, regulatory guidance and regulatory

procedures, e.g. review of safety cases, all necessary to address abnormal

conditions following an accident.

�Application of international recommendations, standards and guidance.

documented in NRPA report 2016:5.


http://www.nrpa.no/en/publications

Take a holistic view of radiation protection

� Emergency preparedness and response, during remediation

� Operational safety and optimisation

� Site characterisation and environmental monitoring

� Control of discharges and public exposure during remediation

� Radiological Environmental Impact Assessment for: planned releases, accidents, transport, treatment and storage of waste

� Contaminated land management and support for long-term site restoration and waste management strategies


More conclusions

� For successful legacy management, it is important to engage a wide range of stakeholders and obtain their support in a transparent and traceable process.

� Effective risk communication is a very important part of the engagement process.

� There is a substantial gap between theory and practice and further international guidance on practical application would be valuable.

� This includes clarification of the application of the concept of emergency, existing and planned exposure situations, and the boundaries between them. (implementation of IAEA and EC BSS)

� A holistic approach to proportionate management of different risks is to be encouraged. This requires review of protection objectives and standards that are applied to different contaminants in different contexts.

““Remediation Techniques and Strategies in Post-Accident Situations” IAEA 13 – 17 June 2016

More conclusions

� Prognostic assessment methods related to legacies that present typically relevant features, such as the nature and extent of contamination are available.

� However, scope exists to improve assessments and bring them into alignment within a common framework of protection objectives. This would then support the consistent application of the principle of optimization.

� There is a need to link national strategies for legacy site remediation and waste management, including radioactive and hazardous waste disposal.

� Development of a common methodology for legacy management and regulation would be useful.


More conclusions$

� Strategic objectives and planning: Plan is necessary for a series

of tasks designed to meet the publicly stated strategic objectives:

� identifying who is responsible for implementing each task, and

� providing powers and resources necessary to those with

responsibility for implementation.


More conclusions$

• <Optimisation> Optimisation is an important aspect of radiological

protection and is best done taking into account social and economic

factors, and not only based on radiological factors such as meeting

reference levels, but other safety and environmental aspects.

• <Storage and disposal> In addition to large quantities of fuel debris,

the decommissioning response to an accident as at Fukushima Daiichi

NPP is likely to generate radioactive waste that exceeds limits for near

surface disposal or intermediate depth disposal. This waste needs to be

appropriately stored and stabilized until a final disposal solution is

developed.

• <International cooperation> Further development of mechanisms for

international cooperation in the event of a major accident would be

useful.


Scope for further cooperation

• Improved international guidance on application of international

recommendations, standards and guidance in post-emergency

phase of major nuclear accident

• All accidents are different! But further international guidance is

needed on pre-planning decommissioning and radioactive waste

management that identifies:

–what planning can be done in advance;

–what planning cannot be performed until the parameters of the

accident are understood;

–scope for sharing of characterisation resources, staff and

equipment nationally and internationally.


Scope for further cooperation

• Improved international guidance needed on:

–transition from regulation as emergency to existing or planned

exposure situation leading to final recovery.

–stakeholder engagement, with emphasis on later stages of

recovery.

–risk communication processes.

–how to characterise, control and regulate chemical risks

alongside the radiological risks.


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