In many regions subjected to the contamination after the ChNPP accident forest products play an important role in radiation impact on the population. The decision making framework to optimise implementation of forest countermeasures in the long term after the ChNPP accident is described. The approach is based on the analysis of the main exposure pathways related to contaminated forest and application of different criteria (reduction of individual dose, cost for implementation; cost of averted dose of 1 man-Sv; secondary ecological effect and psycho-social impact) for the selection of optimal countermeasures strategies. Results of the application of the approach proposed for the study area (Novozybkov district, Russian Federation) are presented. The results emphasize the effectiveness of the application of a flexible decision support technologies for the optimization of countermeasures taking into account radioecological and economic features of contaminated forests.

Among the naturally occurring isotopes the determination of radium is the most difficult ones. In this work some alpha-spectrometric source preparation methods to determine radium were measured. The aim of our work was to investigate the feasibility of MnO2-coated discs for radium detection with a semi-conductor PIPS detector. This method based on the sorption of radium onto MnO2-coated surfaces. Parameters of this method were measured, and efforts were made to solve the incidental problems. In the case of using polyamide discs for base material, the executed experiments were showed that it might be applied to detection of 226Ra, however the resolution was weak. It can be caused by the surface roughness and by the width of the MnO2 coat. In the consecutive investigates we have these parameters changed. Whereas the surface roughness of MnO2 cannot be changed more, smooth surfaces could produce in another way, so there were took several surfaces into account, like stainless-steel, nickel, copper and chrome plate. Regarding our results - in the case of optimal width of MnO2 coat - using MnO2-coated discs is a simple and effective source preparation method in radium measurement.

Should an important release of radionuclides occur in the environment, one would quickly have to assess radionuclide concentration in media and foodstuff, deduce the potential exposition of concerned populations to the radiations, predict the evolution of the situation and propose different scenarios of managing the contaminated zones. To achieve this, the ASTRAL code was created, which can be used by a relatively large group of people composing crisis centres or making predictive impact studies. The starting point of the assessments is the ground deposit of radionuclides: the atmospheric dispersion phase and the cloud exposure are not taken into account here. The calculations achieved concern time evolution of radionuclide concentration in compartments of the agricultural and forest food chain as well as assessment of doses due to external and internal exposure. These values are compared to regulation limits and/or intervention levels. Different simulations of contaminated zones management can be led by applying counter-measures, dispositions meant to reduce the accident's impact on environment and populations. The seventy radionuclides taken into account in the present version are some of those met in case of accidents or during the exploitation of a Pressurized Water Reactor (PWR). They relate to 37 elements: Ag, Am, Ba, Br, Cd, Ce, Cl, Cm, Co, Cr, Cs, Eu, Fe, I, Ir, La, Mn, Mo, Nb, Nd, Ni, Np, Pm, Pr, Pu, Rb, Rh, Ru, Sb, Sm, Sn, Sr, Tc, Te, Y, Zn, Zr. On a temporal point of view, the predictions extend to 3 years after the deposition. The internet technology chosen for this version offers important advantages: the spreading and maintenance of the tool are very easy, the code may be installed on a portable computer, the access to results is much quicker, the interface is very user friendly, so that no training is needed to perform calculations. As for any radioecological tool, a large number of parameters intervene in the calculations. All parameters can be modified, even though different user profiles grant different rights in handling them.

The French-German Initiative for Chernobyl (FGI), implemented by IRSN and GRS from 1997 until the end of 2003, included the “Project on the Radioecological Consequences of the Accident". The most relevant fields of radioecology and post-accidental aspects have been studied. The main goal was to collect and harmonise in NIS countries, the data and results on these topics. These data have been verified, validated and organized in a common georeferenced database REDAC (RadioEcological Database After Chernobyl). For linking the data, topographic maps and maps of contamination by 137Cs have been used and relevant environmental non-radioactive data have been included. The operational database built will also allow the management of the wastes disposal sites. Countermeasures used after the accident have been described and classified. An evaluation of their effectiveness has been done. The database constitutes a tool for the development and validation of operational, assessment and explicative models. This allows the quantification and assessment of radionuclide transfer in the ecosystems. The main parameters influencing the transfers can be identified. REDAC should be completed by further investigations, for example on transuranic elements, and extended to larger geographical zones and combined with others provided by different organisations.

This paper is intended to present the experience feedback of the IRSN's involvement in the reflection on the management of a nuclear crisis. It sums up some results of the French FARMING working group, corresponding to the mobilization of a wide range of Agricultural Technical Institutes and to the appraisal of a compendium of agricultural countermeasures for the rehabilitation of rural contaminated territories in post accidental situations. Indeed, in France, since a few years, this problem has been almost exclusively considered by radiation protection experts, with no involvement of the other concerned actors. But according to the weight of the agro industrial sector in this country and to the problems related to the management of contaminated food in post accidental situations, the cooperation between radiation protection experts and agro industrial stakeholders appeared more and more necessary. Indeed, above all, farmers and other local actors would take a significant part to the rehabilitation actions from the short term to long term of a nuclear crisis period and then share the responsibilities of the crisis management. The working group has therefore opened new debates at the national level and valuable results have been obtained from the meetings at technical and strategic levels.

The Chernobyl reactor accident in April 1986 released some 3-6.105 TBq 137Cs and 2-4.105 TBq 90Sr to atmosphere. About half of this was deposited within 20 km of the site, leading to extensive death of trees and other biota, and the establishment of a human exclusion zone. High levels of contamination remain in this zone. Nonetheless, birch (Betula spp.) and willow (Salix spp.) have recolonised the forest areas, while abandoned agricultural land has succeeded to tall grassland and scrub. This study summarises observations on invertebrate populations in sites with gamma dose rates varying from 0.1 to 140 μSv h-1. Corresponding activity concentrations were 3.103 to 3.106 Bq kg-1 dw 137Cs and 103 to 2.106 Bq kg-1 dw 90Sr in the top 5 cm of soil. Sub-surface bait lamina penetration decreases with increasing concentrations of 137Cs and 90Sr in soil. At the highest levels of contamination there is also some loss of above-ground invertebrate diversity; although little change in total biomass. Trials on earthworms in soils from the region and matched soils spiked in the laboratory have proved variable. However, there is a non-significant indication of depressed growth rates in all contaminated regimes compared to control populations.

The evaluation of the rehabilitation strategies implemented in the contaminated territories of the CIS countries affected by the accident at the Chernobyl Nuclear Power Plant highlighted the need and importance to involve the population in the day-to-day management of the radiological situation, to complement the rehabilitation programme implemented by public authorities. The ETHOS experience in Belarus has revealed that to be effective and sustainable, this involvement must rely on the dissemination of a practical radiological protection culture within all sectors of the population and especially within professionals in charge of public health. The objective of the SAGE Project is to contribute to the development of strategies and guidance for implementing and disseminating such a culture in Western Europe, in case of a nuclear incident or accident with long-term radiological consequences. This paper presents the structure of the project, the stakeholder involvement process which has driven its realisation and the handbook on practical radiation protection culture which was elaborated, with different associated computer tools for people living in a contaminated territory.

From the beginning of 2002, Troyes prefecture has initiated a study about the management of a nuclear crisis caused by an accident at the Nogent-sur-Seine nuclear power plant. Several working groups were created, notably the `Decontamination of soil and food chain' group. The first results of this group, which involves the District Agricultural and Forestry Department, the Farming Chamber, the Institute for Radiological Protection and Nuclear Safety and the Veterinary Division are presented here. The scenario that had been developed for the accident considers the release of 3 radionuclides (131I, 134Cs and 137Cs) in the environment. The scale of the crisis didn't require the evacuation and the sheltering of the population during the emergency phase. The consequences on the local agricultural products (cereal, sugar beet, vine, milk, cow meat ...) have been assessed up to 50 km and different strategies of agricultural countermeasures have been studied regarding to the local constraints (soil types, surfaces and quantities concerned) and to the consequences of their implementation (waste types and quantities, costs). Then, decision-making diagrams summed up the technical results and allowed to deepen the global thought.


In the long term after the Chernobyl accident the introduction of systems of countermeasures in agriculture must be based on the optimization principle. To implement this principle, a concept was used of evaluation of the effectiveness of countermeasures based on a cost-benefit analysis. Countermeasure options were developed separately for collective and private sectors of rural settlements. For each type of farming a range of countermeasures were defined and the optimal ones were identified. The effectiveness of countermeasures was estimated on the basis of integral criteria: cost of averted collective dose (1 man-Sv), overall costs needed for countermeasures introduction and time for fulfilling legal regulations. Based on the most effective countermeasures, optimal combinations (strategies) were developed. An assessment was given of the effectiveness of countermeasures aimed at reducing the radionuclide content in animal products from collective farms and lowering doses to rural residents affected by the Chernobyl accident, based on a comparative cost-benefit analysis. To optimize costs of the rehabilitation of agricultural lands, the most optimal in terms of meeting the standards strategy was determined, which is an address application of countermeasures.

The key issue in the assessment system for radiation protection of wildlife is the establishment of dose-effects relationships for reference representatives of natural biota. Within the frame of the EC Project EPIC “Environmental Protection from Ionizing Contaminants" (2000-2003), a database has been created, which includes about 1600 records from 440 publications in Russian on the dose-effects relationships in wildlife from northern-temperate climatic zones. The EPIC database “Radiation effects on biota" is based on Russian/FSU experimental and field studies; chronic/lifetime exposures are the focus of the data collection. The database information covers a very wide range of radiation dose rates to biota: from below 1E(-5) Gy d-1 up to more than 1 Gy d-1. A great variety of radiation effects are registered in the EPIC database, from stimulation at low doses up to death from acute radiation syndrome at high doses. The paper presents the dose-effects relationships for northern wildlife in the conditions of low-LET chronic irradiation. The system of dose-effects relationships forms the scale of severity of radiation effects at increasing levels of chronic radiation exposure. The system can be used as a basis for establishing criteria for radiation protection of the Northern wildlife.

In the UK, research funded by the Environment Agency/English Nature has provided a series of spreadsheet-based assessment tools for calculating doses received by biota in coastal, freshwater and terrestrial ecosystems. The approach uses the reference organism concept where the organism of interest (feature species) is equated to a particular reference organism (based on its physical geometry and ecology). This paper describes the stages followed to collate additional species-, and site-, specific data and to undertake assessments to determine whether Natura 2000 sites are adequately protected from authorised releases of ionising radiation. The feature species used for the assessment were species listed under the EC Birds and Habitats Directives. The paper will describe the overall assessment process followed by the UK Environment Agency, demonstrating the staged assessment process adopted; how each feature species is mathematically aligned with the most appropriate reference organism geometry; and provide an example of the assessment conducted for the Natura 2000 sites located in the Humber Estuary, UK.

During the next few years the Swedish Nuclear Fuel and Waste Management Co. (SKB) performs site investigations at two sites in Sweden for a future repository of spent nuclear fuel. Parallel an encapsulation plant is planned to encapsulate the spent fuel in copper canister according to the KBS-3 method. The purpose of the SR-Can safety assessment is to show the performance of the canister isolation at different sites for a repository at 500 meters depth in crystalline rock. Moreover SR-Can provides an example how the site specific safety assessment of a deep repository will be made in year 2006-2008. To able to calculate dose and risk for humans and the environment new assessment method were developed for the biosphere. These methods were based on a systems ecological modelling approach and used knowledge from landscape ecology to provide an integrated approach with hydrology and geology considering the discharges in a watershed and calculating consequences in terrestrial and aquatic ecosystems. A range of methods and tools were developed with the aid of GIS and the softwares Matlab/Simulink which facilitated the modelling and increased the understanding of the important processes in the landscape today and the next few thousands of years. In this paper an overview of the program and the novel methods are presented as well as some examples from performance calculations from a watershed in the Forsmark area considering effects on humans and ecosystems.

The EC-funded project FASSET (Framework for ASSessment of Environmental impacT), which completed in 2003/2004, has developed an assessment framework for evaluating the environmental impact of ionising radiation on biota in natural ecosystems. The framework provides practical and scientific support to the international development of recommendations for radiological protection of the environment through the International Commission on Radiological Protection [1]. However, on the basis of experiences from FASSET and other recent developments, it can be concluded that there are challenges remaining before environmental radiological protection can be seen as a natural component of general environmental protection. The major future challenge is the development of an integrated approach where decision-making can be guided by sound scientific judgements. This requires, inter alia, filling basic knowledge gaps relevant to assessment and protection, through targeted experimental, theoretical (including expert judgements) and real case studies; development of risk characterisation methodologies, based on both theoretical and experimental studies; development of screening standards, where appropriate; development of user-friendly assessment tools; and stakeholder involvement, supported by targeted communication strategies. A new EC-funded project, ERICA (Environmental Risk from Ionising Contaminants: Assessment and management), has recently started aimed at some of these issues. The project has four operational work packages, being devoted to the development of practical assessment tools (WP1), risk characterisation (WP2), decision-making involving stakeholder dialogue (WP3) and cases studies (WP4). The implications of the FASSET project and its contribution to prioritisation within ERICA are discussed.

Mathematical computer model is developed to simulate the population dynamics and dynamic mass budgets of the microbial community realized as a self sustainable aquatic ecological system in the tube. Autotroph algae, heterotroph protozoa and saprotroph bacteria live symbiotically with interspecies' interactions as predator-prey relationship, competition for the common resource, autolysis of detritus and detritus-grazing food chain, etc. The simulation model is the individual-based parallel model, built in the demographic stochasticity, environmental stochasticity by dividing the aquatic environment into patches. Validity of the model is checked by the multifaceted data of the microcosm experiments. In the analysis, intrinsic parameters of umbrella endpoint regarding to lethality are manipulated at the individual level, and tried to find the population level, community level especially focused on predator-prey relationship, and revealed the indirect effect of chronic exposure of radiation on the probability of Tetrahymena's extinction.

Current studies within the field of Environmental Risk Assessments associated with the presence of radionuclides in ecosystems tend to implement the usual approach developed for chemicals, that includes four steps: (1) pollutant inventory in the sources of exposure, (2) effect analysis, (3) exposure analysis and (4) risk calculation. In the case of ionising radiation, the third stage involves radiological dose calculation. For humans, this kind of calculation is internationally codified by the ICRP, that provides both models and associated dose coefficients. For non-human biota, this task is a new field of investigations and no international consensus exists at the present time. We thus propose a computer tool to evaluate the dose rate at which the energy produced by ionising radiations is deposited in representative organisms of non-human biota. This energy depends on several parameters, describing the geometry of the relative position of the ionising source and the target, in association with the main properties of the latter. Concerning the source, the radiation type (alpha, beta or gamma) should be taken into account as well as the energy emissions of the concerned nuclides. The target-organism is described by its geometry (assimilated to an ellipsoid characterised by its three axes), its chemical composition and its lifestyle (exposure pathways, dietary habits, behaviour). E.D.E.N. (Elementary Dose Evaluation for Natural environment) is the operational code that we are developing to evaluate the Dose Per Unit of Concentration (expressed in Gy.time-1 / Bq.mass-1 or Bq.volume-1) due to internal and external exposures of any non-human organism to any radionuclide. A user-friendly interface is provided to build the exposure scenario of interest, characterising the target and the sources involved. Several cases are presented to illustrate the possibilities of E.D.E.N.

In Finland, Olkiluoto Island has been selected as the site for disposal of spent nuclear fuel. When creating biosphere models for the safety assessments, local main features and processes need to be taken into account. Characteristic of the site is land uplift (6 mm/a) exposing continuously new land for colonization by plant and animal communities. The forest vegetation succession on these stony, fine-grained till soils starts from deciduous shoreline vegetation and ends in almost pure Norway spruce forests. This has enabled to study processes in soils and forests of different developmental stages, to monitor forest condition and the factors affecting it in other land uplift sites. It has also made possible gradient studies of the succession of boreal mire ecosystems without waiting thousands of years. In this paper, a methodology is described to establish a descriptive model on the development of the biosphere to indicate possible ecosystem distributions and main characteristics on the area on the basis of above-mentioned studies carried out in the area of the Gulf of Bothnia, and of results of the site investigations at Olkiluoto. The description will be used as a basis for selection of appropriate ecosystem modules and parameter values in the subsequent assessment model systems.

The present paper presents, a probabilistic simulation package, Tensit, used for migration calculation of radionuclides from a deep repository for spent nuclear fuel to the biosphere. The package is based on pre-existing codes (Matlab, Simulink and the probabilistic engine @Risk) and is capable of performing migration calculations for the near field, far field and the biosphere for a high level waste repository. In addition to the compartment based models based on transfer factors, the code is also able to handle the more complex ecosystem models (based on flow of carbon and nutrients) either separately or in combination with the compartment models. Comparisons with other codes used for compartment based biosphere modelling as well as example of simple models, more advanced ecosystems and connected ecosystems Landscape model are shown in the paper.

Our aim was to measure the effects of irradiation treatments on soil communities from three different soils. Undisturbed soil cores from three temperate sites (deciduous and coniferous woodland and grassland) were irradiated to give cumulative doses from 0-160 Gy. Cores were incubated at 15$^{\circ}$C and three cores from each treatment sampled after <1, 3 and 8 d. Soil fungi and heterotrophic bacteria were enumerated and the activity and functional diversity of soil microbial communities assessed in terms of their potential to utilise a range of C-sources. Although no significant treatment effects were observed in the numbers of cultivable fungi or fast growing heterotrophic bacteria, the numbers of cultivable Pseudomonas spp. declined in all three soils after irradiation at 80 and 160 Gy. Microbial communities from the coniferous forest soil also showed a dramatic decrease in the metabolic activity and number of substrates utilised by after irradiation at 160 Gy. Gamma irradiation had a greater affect on microbial communities in the two organic forest soils as compared to the mineral grassland soil, this could be related to variations in the physico-chemical shielding properties and in the indigenous communities in terms of radio-resistant species.

The environmental radiation protection has been investigated on the basis of the radiological impacts on biota which are mainly caused by nuclear accidents, and the radiation doses of some plants and animals have been actually monitored in the natural environment. The investigation clearly shows that some radiological effects in the natural environment can be detected before the actual harmful effects occur, because the minimum radiation doses at which harmful effects have been observed are sufficiently high, compared with the radiation doses currently monitored in the natural environment. But, at the same time, it has been accepted that continuing investigations on the radiological effects on ecosystem are indispensable for the establishment of radiation protection system for biota to confirm that the environment has been properly protected from the potential exposure of radiation. The examinations of the risk perception of Japanese people also suggest that the communication with the public about the actual condition of the natural environment on the basis of the scientific data and the opinions of scientists of many fields is very important, because Japanese people tend to be extremely sensitive to the radiological effects on the natural environment.

The involvement of local stakeholders in the decision-making process regarding health, safety and environmental issues is developing in many countries. As far as the management of effluent discharges from nuclear installations in France is concerned, members of Local Commission of Information, including elected people and NGOs, are playing an increasing role in that respect. To deepen the understanding of these risk governance processes, a working group of experts from different institutions was set up in 2000 by the Institute of Radiation Protection and Nuclear Safety (IRSN). Several case studies concerning the involvement of stakeholders were performed, among them: the dialogue process around the discharges of the COGEMA La Hague reprocessing plant, the role of the local liaison committees of the Fessenheim and Gravelines nuclear power plants. Four main elements, contributing to the social trust, emerge from this analysis: 1) the social dynamics of the consultation process, notably with the emergence of “new" stakeholders such as elected people and NGOs; 2) the readability of the plant follow-up from the point of view of local stakeholders and their involvement in the decision process (the relay role of these “new" stakeholders); 3) the contribution of the institutional and pluralist expertise to the social trust (broadening of the range of values taken into account); 4) the issue of the local justification of the plant in the prospect of the sustainable development (no risk being acceptable without counter-parts). This paper addresses these different issues on the basis of the case studies in the perspective of examining the radiological risk governance process.