Radioactivity & the Environment
Programme background
There are many important reasons to expand UK research on radioactivity in the environment. In response to tough targets for reduction of greenhouse gas emissions, it is possible that a new generation of nuclear power plants will be commissioned in the UK and elsewhere. Such a programme is likely to commence with planning applications by 2013, but will continue well beyond.
A second important policy driver is the plan under development by the Nuclear Decommissioning Agency (NDA), as recommended by the Committee on Radioactive Waste Management (CoRWM), to develop a repository for deep geological disposal of intermediate-level and possibly also high-level wastes.
A recent international review under the auspices of the European Commission (FUTURAE: A future for radioecology in Europe, an EU project), which consulted both industry and regulators, has demonstrated key scientific deficiencies in current knowledge to address these challenges.
Another important development is the change in paradigm for environmental protection from radiation. For many decades, radiation protection centred solely on the human species and made the assumption that protection of humans from the adverse effects of radiation exposure would automatically safeguard non-human biota and the environment.
This paradigm has now changed and radiological protection requires consideration of exposures, doses and biological effects in a wide range of organisms referred to as Representative Animals and Plants (RAPs). This change requires a refocusing of research in order to provide the necessary information, both at the level of the individual organism, and of the effects at a population level.
One of the requirements of a programme of new build nuclear power plants will be for very detailed environmental assessments, including evaluation of impacts on the environment as mandated by the EU Habitats Directive 
. This will necessitate an evaluation of the effects of radiation releases upon RAP species, for which information both on environmental uptake and on biological effects is in many cases extremely limited.
There are also considerable weaknesses in our knowledge of the pathways and transfer coefficients for radionuclides in terrestrial and aquatic systems, as well as upon chemical speciation and its impact on environmental pathways.
The UK sites for which local authorities have so far offered expressions of interest to receive the repository have relatively complex geological formations compared to site types being studied elsewhere in the world and warrant generic research on the stability of geological structures on long timescales prior to site selection, as well as very detailed studies once site selection is completed.
Key issues include improved techniques for non-intrusive characterisation of the geosphere, temporal evolution of the geosphere on timescales of up to a million years, gas production and migration, pathways of contaminated groundwater, and solution-solid interactions of radionuclides. This work will require consideration of environmental (including climate) change on very long timescales and its impacts on the security of a repository.
The UK also has a substantial legacy of contaminated sites which could release radiation to the environment, leading to exposures of humans and non-human biota. There are well-recognised weaknesses in models used to evaluate such transfers and further research would be beneficial in providing new knowledge and data to enhance these models.
A Scoping Study was carried out by Professor RJ Pentreath, an internationally-respected expert in this field and a member of the International Commission on Radiological Protection. His recommendations were discussed at an expert workshop. Priority areas identified, included the following:
- Transfer factor values in order to estimate doses that are, or could be, received by different types of biota (particularly the RAPs).
- Dose-effect relationships for the irradiation of RAPs, particularly in the ranges of dose that have been selected as being areas where Dose Consideration Reference Levels apply, and yet for which there is little or no good quality data to support the values.
- Processes affecting the migration of radionuclides through geological media, as informed by the UK Inventory of Radioactive Wastes.
- Characterisation and quantification of the natural background radiation of both humans and biota.
- The impact of environmental change on pathways leading to human exposure, the redistribution of longer lived nuclides around current nuclear facilities and the implications for disposal of radioactive wastes of all forms.
- Enhanced methods of characterising sub-surface geological structures with a view to evaluating their long-term stability and ability to transmit gases and liquids.
The Radioactivity & the Environment research programme has two phases:
- Phase 1 will be a study to produce a report assessing the extent to which UK capacity in this area needs to be rebuilt to deal with both legacy and new build issues. It will take the work of a previous NERC expert group further by additional consideration of radioactivity in the marine environment. The group will analyse evidence about the priority research areas where greater capacity is needed, and develop recommendations on the priority research areas and which elements to include in a capacity building programme.
- Phase 2 will begin with the programme's formal Announcement of Opportunity (AO), the precise content of which will be formulated by the Programme Executive Board following Phase 1.