Advice On The Land Disposal Of Solid Radioactive Waste

Main Category: Radiology / Nuclear Medicine
Article Date: 19 Feb 2009 - 5:00 PDT

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The Health Protection Agency today announces its advice on protecting the public from the disposal of solid radioactive waste.

The recommendations are made to help ensure that future generations are put at no greater risk from solid radioactive waste than today's public.

The Agency recommends that measures are taken to ensure that any potential radiation exposure arising from the disposal of solid radioactive waste during the operationally active stage of a disposal site is as low as reasonably achievable - and certainly below a maximum of 0.15 mSv per year. The average annual dose that a person receives from natural radiation is 2.2 mSv.

After closure, the Agency recommends that the estimated risk of the disposal site causing serious ill health to anyone over the next million years or so should be below a maximum of one in 100,000 per year. The risks to individuals would therefore be extremely low.

The Agency also advises that the highest estimated doses to people who unintentionally disturb a 'near surface' disposal site should be below a guidance level of between 3 and 20 mSv per year, depending on the duration of exposure.

No corresponding dose guidance level is advised for unintentional intrusion into a deep disposal site as these facilities are considered relatively secure.

The Health Protection Agency report updates advice given in 1992 by the then National Radiological Protection Board (NRPB), now part of the Agency. It is intended as an aid to risk assessment during the planning stages of new solid radioactive waste disposal sites, or new 'phases' of existing sites.

HPA Chief Executive, Justin McCracken, said: "This is an important report at a time of increasing interest in nuclear power and in the safe disposal of radioactive waste. Given the long half life of some radioactive waste, the principle behind the advice is that people in the future should have the same level of protection as people have today."

Notes

- The As Low As Reasonably Achievable (ALARA) principle was produced by the International Commission on Radiological Protection (ICRP)

- The Agency's advice is intended as an aid to detailed risk assessment on solid radioactive waste disposal during planning.

- The aim is to ensure that radiological risks to people should be as low as reasonably achievable; economic and social factors being taken into account (ALARA).

- Calculations of doses and risks should take account of the uncertainties and be presented as clearly as possible. Calculations beyond one million years are highly speculative and hence only qualitative arguments should be used at these long times.

- To ensure that individual members of the public are not exposed to unacceptable risks, The Health Protection Agency recommends that, for processes and events affecting the disposal facility, a risk constraint of 1 in 100,000 per year should be applied to the exposure of an individual representative of the more highly exposed individuals in the population. This is applied to the exposure from a single waste disposal facility. The risk is calculated using mathematical modelling on different scenarios of exposure as well as the probability of serious health effects following exposure.

- The Health Protection Agency recommends an annual dose guidance range of between 3 and 20 mSv related to the exposure of an individual representative of the more highly exposed individuals in the population following unintentional disturbance. Values towards lower end of this range are applicable to assessed exposures continuing over a period of a year or more (prolonged exposures), excluding the radon contribution. Values towards the upper end of the range are applicable to assessed exposures that are only short term (transitory exposures). For example where the dose is received within one year and none is received in subsequent years, then 20 mSv applies.

- The Health Protection Agency has a duty to advise Government on radiation issues.

- The International Commission on Radiological Protection (ICRP) published new recommendations in 2007 and the Health Protection Agency is preparing guidance on their applicability to the UK. The Agency consulted on its proposed guidance in autumn 2008. The advice on radiological protection objectives for land-based disposal facilities for solid radioactive waste is consistent with the Agency's proposed guidance on the new ICRP recommendations.

- The environment agencies (Environment Agency, Scottish Environment Protection Agency and Northern Ireland Environment Agency) are publishing their own regulatory guidance on solid radioactive waste disposal. This guidance is available on the environment agencies' websites, including an explanation of its relationship to Health Protection Agency advice.

Health Protection Agency

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