The EXTREME project was launched by the IRSN in 2005 to study the consequences of extreme meteo climatic events on reuptake of stocks and associated fluxes within the various compartments of the geosphere. Large masses of matter transferred during such events are liable to be displaced between locations, leading to higher pollution levels than those arising from average transfer processes, and producing pollutant fluxes that can be equivalent to the fluxes accumulated over several months or even years. This particularly concerns particle-reactive contaminants such as trace metals and long lived artificial radionuclides. The final aim of the project is to estimate the vulnerability of a coastal system (the Gulf of Lions, north western Mediterranean sea) to global change over the next 30 years. Indeed several programs dedicated to climate change predict a potential increase in the frequency of extreme events such as floods, floodings, saharian dust episodes, forest fire events and storms, particularly within the studied area.

Long-term averages of outdoor radon levels give no information on time and spatial behaviour of dispersed radon that exhales from U-mine disposal sites. A comprehensive network of automatic stations for continuous measurements of short-lived radon decay products was installed in the early nineties at the Žirovski Vrh uranium mine. The instruments were positioned at key locations, on-site and off-site uranium mining area, and recorded EEC levels, alpha spectra, and local temperatures, all at least on hourly basis. Analyses of simultaneous records of EEC time series from several locations and analyses of corresponding alpha spectra gave more detailed information on characteristic patterns of radon behaviour and its dispersion from the sites under study. The identified modes of radon dispersion, depending on the presence and type of temperature inversion and the related major findings on the radon impact to the environment are shortly presented.

The main purpose of the study is establishment how radioactive contamination with different exposures affect aquatic living organisms by means of the fluctuating asymmetry determination. Studies are also aimed for the assessment of relative contamination of the water bodies by man-made radionuclides taking into account biological aspects. Represented results of studies are the pilot researches towards to the estimation of bilateral asymmetry of aquatic organisms in conditions of long-term radioactive impact and can be the part of complex radioecological monitoring of aquatic ecosystems within the Chernobyl accident Exclusion Zone in future.

The 5-year multi-national project EURANOS, funded by the European Commission, started in April 2004. Integrating 17 national emergency management organisations with 33 research institutes, it brings together best practice, knowledge and technology to enhance the preparedness for Europe's response to any radiation emergency and long term contamination. After four years of operation the following achievements can be stated. Two handbooks to assist national and local authorities in the management of contaminated food production systems and inhabited areas in Europe have been developed in conjunction with a wide range of European stakeholders. A governance framework for the sustainable rehabilitation of long term contaminated territories has been developed and tested in France. Its implementation in Norway has started. A consistent methodology for calculating the best estimate possible of current radiological situation in both contaminated agricultural and contaminated inhabited areas has been developed. The migration of RODOS (Real-time On-line Decision Support System) to the operating system LINUX is completed. A mass consistent wind field model was implemented together with a particle model for complex terrain. A complete re-engineering of the system has started aiming to incorporate all the user's recommendations collected within the demonstration projects and the operational use of the system in emergency management organisations.

The biological responses induced by low-dose chronic gamma exposure of hydroponically grown Arabidopsis thaliana, irradiated during a full life cycle (seed to seed) were investigated. Applied dose rates were 2300, 375 and 85 µGray h-1. Plants (roots and shoots) were harvested after 24 day (inflorescence emergence), at 34 days (∼50% of flowers open) and at 54 days (silice ripening). Gamma exposure significantly reduced root weight compared to the control but no clear effect of dose rate level on root dry weight was observed. Leaf weight was significantly reduced at the highest irradiation level, only after 54 days exposure. ED-10 was estimated at 10 µGy h-1. Seed germination was not affected by gamma irradiation. For several of the stress enzymes studied enzyme capacity was generally stimulated at the low and intermediate gamma irradiation level compared to the control and highest irradiation level. No pattern was observed in concentration or reduction state of the non-enzymatic antioxidants, ascorbate and glutathione. Lipid peroxidation products in leaves were present highest at full flowering and decreased with exposure level at this growth stage. At the other two growth stages, lipid peroxidation products were unaffected by gamma treatment.

The measurement of diffusive gradients in thin films (DGT) has been proposed as a surrogate for metal uptake by plants. A small-scale experiment was performed to test the predictive capacity of the DGT method with respect to uranium and heavy metal availability and uptake by ryegrass. Correlation analysis was performed to compare the results obtained with the DGT device with more conventional bioavailability indices: concentration in pore water or in selective extractants. Six soils with different histories of uranium contamination and with distinct soil characteristics were screened. For uranium, the bioavailability indices evaluated were highly correlated, indicating that uranium pools assessed were at least partially comparable. For heavy metals, bioavailability indices were hardly correlated. Uranium concentration in the pore water was a better predictor for uranium uptake than amount recovered following selective extraction. The concentration measured with DGT (CDGT) was also highly correlated with plant uptake. However, the significance level was sensitive to the value of the diffusion coefficient (pH dependent or not) used to calculate CDGT. For the heavy metals screened, only in the case of Cd was uptake predicted by CDGT.

A goal of the state policy of the Russian Federation in the field of radiation protection assurance is the consistent reduction of radiation source exposure to workers and to the public up to the acceptable levels during nuclear energy use. The paper considers the following tasks of the state supervision bodies: assurance of the occupational and public protection during prospective development of the nuclear power engineering; protection assurance of workers and of the public during decommissioning of nuclear and radiation hazardous facilities; legislative, regulative and methodic provision of arrangement of safe radioactive waste management; prolongation of the operation lives of the functioning NPP units; incompliance of the real abilities of radiation protection control services and supervision bodies with NRB-99 requirements; implementation of the up-to-date tendency to reduction of areas of health protection zones of nuclear and radiation hazardous facilities; assurance of radiation protection during operation of radiation facilities under irregular conditions; improvement of the guidelines base of the radiation protection state regulation.

A greenhouse experiment was set up to evaluate the potential of enhanced phytoextraction to clean up U and heavy metal contaminated soils. One soil had a naturally high U concentration; the other soil was impacted by the radium extraction industry. Enhancement of solubility and uptake by plants (ryegrass and Indian mustard) was monitored after addition of 5 chemical amendments: citric acid, ammonium citrate-citric acid mixture, oxalic acid, EDDS and NTA. Solubilisation and uptake were highly influenced by the amendment applied and soil-plant combinations. For U, citric acid, the ammonium citrate-citric acid mixture or EDDS were most effective in increasing U uptake. EDDS was most effective in increasing Cu in mustard and ryegrass and Pb in ryegrass shoots. For other metals, increase in uptake was limited to at most a factor 5. Percentages annually removed with biomass ranged from 0.0002% to 1.52%., and were lowest for U, Cr and Pb and highest for Cd. A targeted 10% reduction in soil contaminant would require 7 years for Cd, 35 and 52 years for Cu and Zn, 203 and 384 years for U and Pb and 9433 years for Cr. Phytoextraction is hence not a feasible technique to decontaminate historically contaminated soils.

The problem of low level waste management is currently the issue of the day. In the context of the present work, these wastes are referred to as very low level wastes (VLLW), similar to some foreign States and like in IAEA publications. The solution of VLLW management is possible through introduction of this waste category into the system of the national classification. The waste management problem solving at SevRAO facility requires elaborating provisions relating to VLLW management procedure, variants of release from regulatory control, disposal options, sitting the disposal landfills in terms of SevRAO features, forming both radiation situation and occupational doses. A conclusion is made that industrial waste containing man-made radionuclides with up to 30 kBq/kg specific activity may be safely disposed at VLLW landfill in Andreeva Bay and Gremikha and the level of the industrial waste clearance from the radiation control corresponds to 0.3 kBq/kg.

In 1985, at Novovoronezh NPP (NVNPP), the leakage occurred of liquid radioactive waste (LRW) from the storage facility No. 2 (SLW-2) into the soil. According to the fulfilled assessments, the total volume of LRW penetrated into the soil was about 480 m3, the total activity of 60Co was 76 TBq (2050 Ci) and of 137Cs – 15 TBq (390 Ci). The total activity of other radionuclides was less than 0,037 TBq (1 Ci). The salt contents in LRW were 120–150 g/l. Thus, 60Co was the main contaminant of the environment.

The paper elaborates on the international safety standards related to demonstrating the safety of radioactive waste disposal and provides on overview of the intercomparaison and harmonization projects presently underway.

Sediments may act as a sink for nutrients and trace metals after deposition. It may pose a risk for surface water quality and ecosystem health when environmental changes lead to release nutrients and trace metals stored in these sedimentary stocks. The management of the quality of freshwater systems needs to understand the processes of remobilisation of these stocks. This mobility is dependent on the erosion, on the interstitial diffusion of the mobile phases and on the bioturbation. These mechanisms depend on early diagenetic processes that condition the physical and biogeochemical properties of the sedimentary column. These properties are mainly influenced by the redox transformations resulting from oxidation of the organic matter by the microbial activity. These reactions generate vertical profiles of nutrient and metals concentrations along the sedimentary column. This paper aims to propose a modelling and an experimental protocol to determine vertical profiles of nutrients and trace metals in saturated sedimentary columns of freshwater systems. The modelling approach is based on a coupling between bio-geochemical processes [1], interstitial diffusion [2, 3] and solid-liquid exchanges. The main originality of the model is the pH determination that is directly calculated from the pore water concentrations of the ionic species. As illustration, this paper presents an application to natural sediment cores collected in the Durance Rivers.

Compartment models are widely used for the evaluation of radiological consequences to man and biota in the marine environment over large spatial and long temporal scales. The model developed at the Norwegian Radiation Protection Authority (NRPA) is based on a compartment modelling approach that includes terms describing dispersion of radionuclides into oceanic space with time (non-instantaneous mixing in oceanic space). In this paper the latest modification of the NRPA model will be presented. The main improvement concerns the “time of availability” parameters (i.e. the times at which dispersed radionuclides reach compartment boundaries). The modifications have been implemented through the use of a comprehensive 99Tc data set collected under the course of the project “RADNOR” and through comparison with the results of simulations provided by the 3D hydrodynamic NAOSIM model. The present version of the NRPA model describes the dispersion of 99Tc in the Arctic Ocean and seas with a significantly improved precision for some marine regions. Results of the calculations indicate that defined “time of availability” parameters are in good agreement with transit times observed in the actual marine environment.

Assessments of radiation exposure of reptiles may be required in some countries as many species are protected. However, there are few data available for the transfer of radionuclides to them, especially in terrestrial ecosystems, and consequently, no specific peer reviewed reptile data have been used in the derivation of default transfer parameters in the ERICA Tool. Twenty samples of Lacerta agilis (sand lizard) and five of Natrix natrix (grass snake) were collected from two sites within the Chernobyl Exclusion Zone and analysed for Pu-isotopes, 137Cs and 90Sr. Corresponding activity concentrations for soil from the sampling sites were available. These data have been used to derive concentration ratios (CR) (i.e. reptile whole-body fresh weight activity concentration relative to the dry weight activity concentration in soil). CR values for N. natrix tended to be lower than those for L. agilis. The CR values derived in this paper will be used to improve the default values provided within the ERICA Tool. Whole-body activity concentrations determined in the reptile samples were broadly comparable with data available from the same sampling sites for small mammal species.

Countermeasures to reduce the transfer of a radionuclide from soil to plants are usually based on saturating the soil with a stable element that is a chemical analogue of that radionuclide. But when a radioactive contamination event occurs, it is seldom due to the evacuation of a pure radionuclide such as 137Cs. Instead, a mixture of radionuclides may be released into the environment. The countermeasures applied to reduce the transfer of one of them may also influence other radionuclides. We have developed an experimental procedure to check whether radiocaesium countermeasures are appropriate when other radionuclides are also involved, or have some disadvantages that may limit their use. It consists of growing wheat seeds under controlled laboratory conditions using Neubauer's plantlet method. This method has been in use for many years as a small-scale screening procedure to check a soil's capacity to provide the potassium that plants need as a nutrient. In particular, we used it to study the effectiveness and the disadvantages of the application of a potassium salt fertilizer to a soil contaminated with 134Cs, 90Sr, and 60Co. This countermeasure indeed reduced the uptake of 134Cs, but it also enhanced the uptake of 60Co. This enhancement was higher for the wheat stems than for the roots. For 90Sr, there was observed a slight increase due to the fertilizer.

For appropriate safety assessment of TRU waste disposal, gasification ratios and distribution coefficients (Kd) of 14C labeled [1, 2-14C] sodium acetate were determined by batch experiments for a Japanese paddy soil sample. Approximately 60% of the total added C-14 was released from the flooded paddy soil into the air as gas forms during 7 days shake-incubation periods. In the present study, the paddy soil was contacted with deionized water and well water, and the lower gasification ratio was found for the well water sample. The similar result was observed for the Kd values. Values of Kd varied from 51 to 138 mL g-1. The lower values were observed when the soil was contacted with well water. When the microorganisms in the samples were killed by glutaraldehyde, both gasification ratios and Kd values were nearly zero. These results suggested that microorganisms responsible for the behavior of C-14 in biosphere. In addition, water characteristics such as dissolved ions, pH and electrical conductivity would affect the gasification ratio and the Kd values.

Olkiluoto Island on the western coast of Finland has been selected as a repository site for spent nuclear fuel in Finland. This study aimed at identifying differences in concentration ratios (CR), and their distributions, for the elements analysed on soil and vegetation samples taken on the island (Al, B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, P, S, Zn). Many of the elements can be considered to be chemically analogous to radionuclides that, potentially, can be released from the repository. Differences between the soil and vegetation in different tree age, tree species and site fertility classes typical of the forest ecosystems in Olkiluoto were investigated. Lognormal distributions were fitted to the different groupings of the CR data calculated on the basis of the results from 94 sampling plots. In most cases no significant differences were found between the different groupings for a specific element when the 95% confidence intervals were applied. According to the results based on real site data for CRs in forest ecosystems on Olkiluoto, it appears that the current CR-based approach to radionuclide modelling in forest ecosystems is problematic due to the large variation in parameter values and in their practical definition.

This paper summarizes research activities in National Institute of Radiological Sciences (NIRS) for evaluation of the radiation effects on selected terrestrial and aquatic organisms as well as the ecosystems. Seven organisms, conifers, fungi, earthworms, springtails, algae, daphnia and Medaka are presently selected to study. For the estimation of possible radiation dose, transfers of radionuclides and related elements from medium to organisms are evaluated. Dose-effect relationships of acute gamma radiation on the survival, growth, and reproduction of selected organisms have been studied. Studies on the effect of chronic gamma radiation at low dose rate were also started. In order to understand the mechanism of radiation effects and to find possible indicators of the effects, information of genome- and metagenome-wide gene expression has been collected. Evaluation of ecological effects of radiation is more challenging task. Study methods by using three-species microcosm were established, and an index for the holistic evaluation of effects on various ecological parameters was proposed. The microcosm has been simulated as a computer simulation code. Developments of more complicated and practical model ecosystems have been started. The Denaturant Gradient Gel Electrophoresis (DGGE) has been applied on soil bacterial community in order to evaluate the radiation effects on soil ecosystems.

There is general international acceptance of the need to demonstrate that the environment is protected from ionising radiation. In some countries requirements and guidelines for the protection of non-human biota are already in place. As a consequence a number of models and approaches have been proposed for the estimation of the exposure of non-human biota to ionising radiation. The IAEA EMRAS programme's Biota Working Group has conducted the most comprehensive intercomparison of the predictions of these approaches to date. In this paper, we present an overview of the activities of the Biota Working Group concentrating on its conclusions and recommendations.

Evaluation of the safety of high-level radioactive waste repositories is a requisite included in radioactive waste management policy. Criteria for the safety of those facilities require protection of the population and the environment over a time scale appropriate to the characteristics of the radionuclides present in the disposed wastes. In order to demonstrate compliance with regulations, a quantitative analysis of the system must be carried on, including the transport of radionuclides from the facility to the biosphere and through, and the assessment of radiation doses from both external and internal exposure. Previous assessments, demonstrate that some radionuclides contribute more to the annual dose to humans. Among these, 14C and 36Cl must be considered. Realistic models to simulate transport of radionuclides in the environment are essential. A biosphere model should represent the transport and accumulation of radionuclides in the different media, and include characterization of the pathways through which the contaminants reach the population giving rise to the exposure to radiations. This paper shows general guidelines for the behaviour of 14C and 36Cl in the environment and the definition of a conceptual model of radionuclide transport in the biosphere.