The role of experts in the development of recovery handbooks: UK and European experience.

The importance of involving experts in the development of strategies for managing areas contaminated as a result of a nuclear accident is now well recognised. Following the Chernobyl accident in 1986, the initial focus, quite understandably, was on the technical aspects of reducing doses to the affected population. Subsequently, work carried out in the UK and elsewhere in Europe looked at the broader impacts of protective actions on agriculture, the environment, and society. From 1997, a group of experts from academia, government, and non-government organisations met regularly in the UK to debate these issues. One of the outputs included the first version of the UK Recovery Handbook for Radiation Incidents in 2005. Based on the success of the UK group, a European network of experts was established, leading to the development of European handbooks in 2009. The UK handbooks are living documents that are updated regularly with substantive input from experts.

Decision making for late-phase recovery from nuclear or radiological incidents: new guidance from NCRP.

In 2010, the US National Council on Radiation Protection and Measurements (NCRP) established a scientific committee (SC5-1) to prepare a comprehensive report on the framework and approach for optimising decision making in late-phase recovery from nuclear or radiological incidents that lead to wide-area contamination. The NCRP report builds on recommendations from the International Commission on Radiological Protection's (ICRP) Publication 111 which specifically addresses the protection of people living in long-term contaminated areas. Based on this approach, the report addresses all relevant dimensions: health, environment, economic, psychological, cultural, ethical, and political. NCRP, like ICRP, considers optimisation to be the best approach to decision making for balancing these multiple risk factors in situations involving wide-area contamination where the conventional clean-up approach may encounter some serious constraints. The NCRP report describes optimisation as an iterative process that can be broken down into a series of steps, all of which involve deliberations with stakeholders as a necessary element for a community-focused recovery effort. The steps, elaborated on in the report, range from defining the situation to a series of actions involving assessing impacts, evaluating options, developing a strategy, and demonstrating its successful implementation. In conclusion, the NCRP report makes a series of recommendations aimed at enhancing and strengthening late-phase recovery following a major nuclear or radiological incident.

Variation in stakeholder opinion on countermeasures across Europe.

A compendium of agricultural countermeasures and rural waste disposal options has been compiled as part of the EC STRATEGY (Sustainable Restoration and Long-Term Management of Contaminated Rural, Urban and Industrial Ecosystems) project. The compendium was discussed by the FARMING (Food and Agriculture Restoration Management Involving Networked Groups) network of stakeholders during meetings of national panels in the UK, Finland, Belgium, Greece and France in 2002. Their preliminary feedback has been summarised in terms of whether an option is generally acceptable, unacceptable or only acceptable under specific circumstances. A considerable divergence of opinion between national panels was apparent for many of the options considered. This could be attributed to differences in geomorphology, climate, land management, infrastructure, consumer confidence, sociopolitical context and culture. Where consensus was reached between stakeholders it was generally for those countermeasures that provide public reassurance, sustain farming practices and minimise environmental impact. Furthermore, whilst there was general agreement that contaminated food should not enter the food chain, many of the options proposed for its subsequent management were not generally acceptable to stakeholders.

Achievements, difficulties and future challenges for the FARMING network.

The EC FARMING network (Food and Agriculture Restoration Management Involving Networked Groups) was set up to bring together the many and diverse stakeholders who would be involved in intervention following wide scale radioactive contamination of the food chain, so that acceptable strategies can be developed for maintaining agricultural production and safe food supply. The network comprises stakeholder panels in the UK, Finland, Belgium, France and Greece that have met regularly since 2001 to debate, discuss and exchange opinion on the acceptability, constraints and impact of various countermeasure options and strategies. The objectives of this paper are to consolidate the main achievements of the FARMING project over the period 2000-2004, to highlight the various difficulties that were encountered and to discuss the challenges for engaging stakeholders in off-site emergency management and long-term rehabilitation in the future.

Stakeholder involvement facilitates decision making for UK nuclear accident recovery.

The importance of major stakeholders participating in the formulation of strategies for maintaining food safety and agricultural production following a nuclear accident has been successfully demonstrated by the UK 'Agriculture and Food Countermeasures Working Group' (AFCWG). The organisation, membership and terms of reference of the group are described. Details are given of the achievements of the AFCWG and its sub-groups, which include agreeing management options that would be included in a recovery handbook for decision-makers in the UK and tackling the disposal of large volumes of contaminated milk, potentially resulting from a nuclear accident.

Overview of the wisdom stakeholder workshop on restoration management.

A Workshop to extend the Involvement of Stakeholders in Decisions On restoration Management (WISDOM) was held at New College, Oxford from 15 to 17 September 2003. The aim was to promote awareness and interest in the wider application of stakeholder involvement in the formulation of strategies for the management of contaminated agricultural land and produce following a nuclear accident. The workshop, through 25 plenary papers and a set of two facilitated discussion sessions, provided valuable feedback on a wide range of issues including technical and social factors affecting countermeasure selection, acceptability of intervention levels, the challenges of rural waste disposal and crisis management. The workshop achieved its aim and the findings will be disseminated widely. Stakeholder groups are already active in the UK, Finland, Belgium, France and Greece; there was commitment from participants to establish further, similar groups in other member states within the European Union.

Predicting the transfer of radiocaesium from organic soils to plants using soil characteristics.

A model predicting plant uptake of radiocaesium based on soil characteristics is described. Three soil parameters required to determine radiocaesium bioavailability in soils are estimated in the model: the labile caesium distribution coefficient (kd1), K+ concentration in the soil solution [mK] and the soil solution-->plant radiocaesium concentration factor (CF, Bq kg-1 plant/Bq dm-3). These were determined as functions of soil clay content, exchangeable K+ status, pH, NH4+ concentration and organic matter content. The effect of time on radiocaesium fixation was described using a previously published double exponential equation, modified for the effect of soil organic matter as a non-fixing adsorbent. The model was parameterised using radiocaesium uptake data from two pot trials conducted separately using ryegrass (Lolium perenne) on mineral soils and bent grass (Agrostis capillaris) on organic soils. This resulted in a significant fit to the observed transfer factor (TF, Bq kg-1 plant/Bq kg-1 whole soil) (P < 0.001, n = 58) and soil solution K+ concentration (mK, mol dm-3) (P < 0.001, n = 58). Without further parameterisation the model was tested against independent radiocaesium uptake data for barley (n = 71) using a database of published and unpublished information covering contamination time periods of 1.2-10 years (transfer factors ranged from 0.001 to 0.1). The model accounted for 52% (n = 71, P < 0.001) of the observed variation in log transfer factor.

Soil-to-plant transfer factors for radiocesium and radiostrontium in agricultural systems.

A database of soil-to-plant transfer factors for radiocesium and radiostrontium has been compiled for arable crops from published and unpublished sources. The database is more extensive than previous compilations of data published by the International Union of Radioecologists, containing new information for Scandinavia and Greece in particular. It also contains ancillary data on important soil characteristics. The database is sub-divided into 28 soil-crop combinations, covering four soil types and seven crop groups. Statistical analyses showed that transfer factors for radiocesium could not generally be predicted as a function of climatic region, type of experiment, age of contamination, or soil characteristics. However, significant relationships accounting for more than 30% of the variability in transfer factor were identified between transfer factors for radiostrontium and soil pH/organic matter status for a few soil-crop combinations. Best estimate transfer factors for radiocesium and radiostrontium were calculated for 28 soil-crop combinations, based on their geometric means: only the edible parts were considered. To predict the likely value of future individual transfer factors, 95% confidence intervals were also derived. A comparison of best estimate transfer factors derived in this study with recommended values published by the International Union of Radioecologists in 1989 and 1992 was made for comparable soil-crop groupings. Whilst there were no significant differences between the best estimate values derived in this study and the 1992 data, radiological assessments that still use 1989 data may be unnecessarily cautious.

Effect of potassium (K) supply on the uptake of 137Cs by spring wheat (Triticum aestivum cv. Tonic): a lysimeter study.

A lysimeter experiment was carried out on a relatively infertile soil to examine the effect of potassium fertiliser application on the uptake of radiocaesium by spring wheat. Porous ceramic cups were used to obtain samples of soil solution. Results showed that the uptake of radiocaesium by spring wheat was reduced by the addition of potassium. However this inhibitory effect was less marked at later stages of plant growth due to factors such as the spatial variability of potassium within the soil, differences in root distribution down the soil profile and age-related demand for potassium by the plant. There was some evidence that a negative power function could be used to describe the relationship between the concentration of 137Cs in the plant and concentrations of potassium or 137Cs:K quotients in soil solution over the whole experimental period. Practical implications of potassium fertilisation in terms of reducing uptake of radiocaesium by crops are discussed.

Options for managing foodstuffs contaminated with radiocesium and radiostrontium.

In the event of a future nuclear accident, foodstuffs with activity concentrations greater than specified intervention levels would be banned for human consumption. Three broad strategies could be used to manage such produce: in situ treatment, alternative uses, or disposal. This paper describes an assessment of the practicability of nine potential management options for contaminated arable crops for use in the UK. Practicability is affected by six factors: technical feasibility, capacity, cost, environmental impact, radiological impact, and acceptability. These were assessed quantitatively, where possible, through consultation with experts from a range of organizations, and a detailed radiological impact assessment was undertaken. Suggestions are made on the most practicable options for managing cereals, field-grown vegetables, and annual fruit contaminated with radiocesium and radiostrontium. Options are available for managing foodstuffs with activity concentrations of up to 8.3 x 10(4) Bq kg(-1) 134Cs, 2.1 x 10(5) Bq kg(-1) 137Cs, 7.7 x 10(8) Bq kg(-1) 89Sr and 3.0 x 10(5) Bq kg(-1) 90Sr, which are well in excess of those expected from design basis accidents.

Derivation of working levels for radionuclides in animal feedstuffs for use following a nuclear accident.

Maximum permitted levels of radiocesium in marketed animal feedstuffs have been specified by the European Commission for use in the event of a future nuclear accident. However, more specific guidance is required for use under UK conditions. Using information on typical animal diets, relative activity concentrations in feedstuffs and feed-to-product transfer, practical working levels have been derived for (134,137)Cs and 90Sr in animal feedstuffs and drinking water; application of these levels should ensure that activity concentrations in milk, meat, or eggs do not exceed the relevant Council Food Intervention Level. Despite the complexity of some animal diets, only one or two feedstuffs typically contribute 5% or more to intakes of activity. The working levels for radiocesium in these feedstuffs ranged from a factor of 20 higher than the maximum permitted levels to a factor of around 20 lower. In most cases, the maximum permitted levels are unnecessarily cautious. Working levels for 90Sr in feedstuffs are generally higher than those for radiocesium, except for feedstuffs for dairy cattle and laying hens. Factors affecting the practicability and effectiveness of changes in diet as a countermeasure to reduce activity concentrations in animal products were also considered within this study.

Options for the management of foodstuffs contaminated as a result of a nuclear accident / Options for the management of foodstuffs contaminated as a result of a nuclear accident

A review has been carried out of the various options available for managing foodstuffs with activity concentrations in excess of the intervention levels specified by the European Union. There are three broad management options: in situ treatments, alternative uses and disposal. A total of eleven potential options were evaluated. The practicability of each option for use in the UK in the event of a future nuclear accident was assessed. This is affected by six main factors: technical feasibility, existing capacity, cost, environmental impact, radiological impact, and acceptability to the waste regulators, operators, farmers and members of the public. These factors have been evaluated quantitatively where possible. Recommendations are made on the most practicable options for managing cereals, vegetables, fruit and milk contaminated with radiocaesium and radiostrontium, and milk contaminated with 131I