A screening ecological risk assessment was performed for regulatory compliance at two Ontario nuclear power generation station sites to establish design requirements for a contaminant-monitoring program and to address the need for non-contaminant stressor management. Site-specific assessments went beyond traditional contaminant risk assessment to include stressors associated with land-use change, cooling water systems and site storm water runoff. Valued terrestrial and aquatic ecosystem components were selected from species lists after stakeholder consultation, and contaminants of concern were selected based on their relative loadings, and with respect to regulatory and literature-based benchmarks. Predictive modeling was used to estimate chemical and radionuclide exposures and likelihood of effects. Potential adverse effects on biota were predicted for aqueous emissions of chlorine and storm water but not for radionuclides. Retrospective analyses of field monitoring were used to determine likelihood of effects from non-contaminant stressors. Individual-level adverse effects were observed for fish losses from cooling water intake. Depending on the site and the biological species, either beneficial or adverse effects from thermal discharge were observed. Follow-up studies include monitoring, laboratory study, computer modeling and mitigation. Field monitoring will generate more precise species-level estimates of intake fish losses, magnitude of fish response to thermal discharge and chlorine concentrations in near-field discharge waters. Laboratory study is determining the effectiveness of intake fish loss mitigation technology. Computer fish population models are being used to design field studies and interpret individual-level effects. Mitigation includes storm water controls and habitat biodiversity management projects to offset past losses from site development and construction. Contaminant monitoring is planned to collect necessary information to verify site specific risk assessment model predictions and confirm model parameters and assumptions. The updated contaminant risk assessment models will be used to adjust site monitoring programs.

This paper presents new data on concentration factors (CFs: concentration kg-1 biota/concentration l-1 seawater) for several marine species-radionuclide pairs, in three regions: coastal waters of Ireland, eastern Irish Sea and coastal waters of Norway. The CFs were estimated using data from long-term monitoring programmes, obtained for radiological protection purposes. The practical constraints of using such data sources are discussed. CFs were obtained for a range of fin fish, crustaceans, molluscs and brown seaweed, for one or more of the following radionuclides: 99Tc, 137Cs, $^{239,240}$Pu and 241Am. In general, there was a relatively high degree of variability in the values obtained, and it was not possible to discern systematic regional or time-dependent differences. However, for two datasets in the eastern Irish Sea (137Cs in winkles and crabs) and a number of datasets (137Cs in various species of fish) in the western Irish Sea there was a statistically significant increase in the CF over the monitoring periods. Significant gender differences were found for 99Tc in lobster. The results are compared with current IAEA recommendations and are discussed in relation to the influence of contemporaneous discharges and the possible impact of remobilised radionuclides on bioavailability.


The peculiarities of 90Sr, 137Cs, 239,240Pu accumulation by some species of herbaceous plants in radioactive contaminated areas of nuclear enterprises in Russia have been investigated. Gas and aerosol discharge from Beloyarskaya NPP (which operates for more than 30 years) did not make considerable contamination of soil-vegetational cover in the 30-km zone. In close proximity to the epicenter of nuclear accident of 1957 in the Urals the concentration of the main contaminant (90Sr) in the plants reached maximal value (tens and hundred of thousands of Bq kgdw-1 depending on species belonging of plant). The concentration of 90Sr in aboveground phytomass of plants growing within floodplain of the Techa river ecosystems is thousands of Bq kgdw-1; at the same time, the 137Cs concentration is units of Bq kgdw-1. The absence of direct dependence between the radionuclides content in the soils and their concentration in aboveground phytomass is noticeable. The values of the radionuclides transfer coefficients in the plants were estimated as well as the content in the soils of their water-soluble and firmly fixed physic-chemical forms. The radionuclides have been ranked into a row according to their mobility in observed soils and biogeocenotical soil-plant link.

La France procède à des expérimentations nucléaires en Polynésie françaisedepuis 1966. D'abord aériennes, elles sont devenues souterraines depuis 1975.Dans le cadre de la surveillance de ces expérimentations, le contrôle de lateneur en césium 137 de la noix de coco est réalisé sur l'ensemble du territoirede la Polynésie française. Après avoir décrit la méthodologie, nous présentonsles résultats des 2 589 échantillons prélevées de 1967 à 1988. Les teneurs maximalestrouvées depuis 1967 sont de 52 Bq.kg-1 pour l'eau de coco et de 289Bq.kg-1 pour le coprah. La décroissance de la teneur en césium 137 estconstante, sans discontinuité, à partir de 1974 quel que soit l'éloignement parrapport aux sites d'expérimentations. L'équivalent de dose d'irradiation engagédû au césium 137, délivré par la consommation d'eau de coco et de coprahreprésente quelques microsieverts par an.

Assimilation of observations is a powerful tool to improve the predictive capabilities of models for radionuclide transport and fate. We describe results of numerical experiments on assimilation of the data on radionuclide contamination of the Black Sea in the result of Chernobyl accident using the three-dimensional model of circulation and radionuclide transport THREETOX. Data assimilation can be formulated as a procedure that contains two steps: update and forecast. On the update step THREETOX is run from the time of release or deposition to the time of the forecast using the updated input from all the measured data available at this period to be assimilated. On the forecast step THREETOX is run from the forecast time to the end of the modeling period using the results of the update step to produce the forecast of radionuclide transport. The data assimilation method called “method of iterations to optimal solution" (IOS) was used at the update step. The approach has been applied to the assimilation of the observational data of 137Cs concentration measured in the “Typhoon" surveys for the period June 1986 to September 1990. From the results of numerical experiments we conclude that usage of a data assimilation procedure can essentially improve predictive capability of the models for radionuclide transport. The computational time for the data assimilation method chosen is small in comparison with the general time of calculations. Results from the study will provide a better understanding of the processes of radionuclide transport in the seas. This novel approach was implemented in the EU DSS RODOS for the real-time simulation of radioactivity transport in the marine environment.

Radiocarbon (C-14) is potentially important in radioactive waste. Because the carbon transfer through the biosphere is principally different from the transfer of other radionuclides, using an empiric soil-to-plant transfer coefficient (also called soil/plant concentration ratio) in the same way as with other nuclides is inappropriate and can lead to wrong results in biosphere assessment models. C-14 concentrations and fluxes in the biosphere are strongly influenced by the concentrations and fluxes of stable carbon. We developed a new process-based model of the soil to plant transfer of C-14 for the use in the safety assessments of radioactive waste repositories. The model describes the steady-state nuclide abundance in the plants due to the fluxes of water and solid matter within the biosphere system. To study the model sensitivity to parameter variations, parameter variations were studied. We found that the carbon cycle plant => soil => canopy determines the uptake of C-14 by crops. The major parameters are the plant productivity (yield) and the exchange rate of carbon between the air within the canopy and the general atmosphere. The quantification of this exchange rate of carbon is, however, a major open issue.

Calculations are presented of the effective dosesper unit neutron fluence according to the ICRP publications 60 and 103.Monte Carlo N-Particle (MCNPX) code was used for six geometricalconditions of irradiation (Anterior-Posterior, Posterior-Anterior,Left-Lateral, Right-Lateral, Rotation and Isotropic) on Oak RidgeNational Laboratory (ORNL) modified mathematical adult phantomsfor monoenergetic neutrons from 10-9 MeV to 20 MeV. The conversioncoefficients were compared with the results of an analytical phantom(Medical Internal Radiation Dose (MIRD-5)) and some voxel model(ICRP/ICRU Reference Voxel Phantom (ICRP/ICRU RVP), HANAKO, TAROand Visible Human Project (VIPMAN)). From these comparisons, one canconclude that large discrepancies between data sets appear whenwR and different sizes of the phantoms have been used for calculations.Furthermore, the differences in applied Monte Carlo codes or simulatedbody models could make some discrepancies less than 15%.

The Tejo River flows between Spain and Portugal discharging in the Atlantic Ocean. In its Spanish section receives discharges from three nuclear power plants (NPP) being the Almaraz NPP located nearby the Portuguese border. This paper summarizes and analyses the radionuclide concentrations in surface water, sediments and fish in Tejo River from the years 2001 to 2005. The surface waters, following radiochemical procedures, were analysed for total and residual beta, 137Cs and 90Sr by beta measurements using proportional counters and for 3H by liquid scintillation counting, after isotopic enrichment. Radionuclide concentrations were determined in sediments and fish by gamma spectrometry. The results obtained for 137Cs and 90Sr in surface waters are low and of the order of magnitude of the background. Regarding the 3H, the activities are higher than those obtained for other rivers. The levels of artificial and natural radionuclides in fish are below the minimum detectable activity with the exception to 40K. For sediments, the 228Ra, 226Ra and 137Cs concentrations increase with the decreasing of the sediment size. An opposite behaviour was observed for 40K. The data show that the radioactivity levels in Tejo River are low and within the values measured in other Portuguese rivers except for 3H in water which values are higher due to the influence of the Almaraz NPP.

Non-governmental environmental organisations (environmental NGOs) may consider the issue of radiological protection of the environment differently to other interested parties such as regulators or industry. While environmental NGOs are broadly positive towards the current emphasis and engagement on radiological protection of the environment per se, there remain concerns about the precise meaning of the term, the scope of the system being developed and the ultimate objectives of the current initiatives. Ongoing work on developing a “reference organism” approach to radiological protection may contribute to a better understanding of the possible impacts of inputs of radioactivity into the environment. However this approach may lead to narrowly-defined regulatory compliance criteria that do not ensure effective environmental protection. A more comprehensive approach is needed in order to provide a sufficient basis for developing an effective system for protection of the environment. At the core of such a system would be an ecosystem-based and precautionary approach, drawing on developments and experience in environmental protection across a range of disciplines, industrial sectors and human activities. To be considered sustainable, any future nuclear developments would need to be undertaken fully within the framework of such an integrated, holistic system of environmental protection.

The need of less conservative but reliable risk assessment for accidental tritium release was recognized in the frame of present debate on nuclear energy future. While the fusion reactor is only in research phase and risk assessment are not extremely stringent, Romania faces a debate on near future of nuclear energy with heavy water reactors, known to have a large load and release of tritium. Both tritium and 14C are key radionuclide for CANDU and are also directly involved in the life cycle of plants and animals. An interdisciplinary approach is proposed in order to better handle the environmental transfer of tritium under accidental conditions and preparatory steps are presented.

Le synchrotron Saturne II, installé sur le site du CEA Saclay fonctionnant depuis 1979 devrait être démantelé dans les prochaines années. Saturne pouvait accélérer des protons, des deutons, des hélions, et desions lourds (jusqu'au Krypton) avec une énergie en protons de 100 à 2 900 MeV. Des calculs avec un code Monte Carlo (FLUKA), couplé à un code de calcul d'activation/évolution (DARWIN/PEPIN) ont été menés pour prédire l'activation dans les protections en béton de l'accélérateur. Les produits d'activation sont en majorité dus à des réactions de capture de type (n, γ), 22 % de l'activation étant due à des neutrons d'énergie supérieure à 20 MeV$\backslash$226type (n,p) ; (n, spallation) etc. Ces calculs ont été comparés à des mesures des émetteurs γ, du 3H, du 45Ca et du 55Fe d'échantillons prélevés par carottage sur des bétons ordinaires (2,35 g cm-3), lourd baryté (3,6 g cm-3) et très lourd riblonné (4,8 g cm-3). Le rapport entre calcul et mesure varie de 1 à 6 suivant le type de béton considéré et la profondeur deprotection. De même, les mesures ont été comparées à d'autres pour des accélérateurs différents (énergie et particules). On montre que l'activation dépend de la charge intégrée sur les cibles de production et de l'énergie des particules notamment pour le profil d'activation en profondeur.

Over the past few decades there has been some discussion concerning the increase of the natural background radiation originated by coal-fired power plants, due to the uranium and thorium content present in combustion ashes. The radioactive decay products of uranium and thorium, such as radium, radon, polonium, bismuth and lead, are also released in addition to a significant amount of 40K.

Since the measurement of radioactive elements released by the gaseous emissions of coal power plants is not compulsory, there is a gap of information concerning this situation. Consequently, the prediction of dispersion and mobility of these elements in the environment, after their release, is based on limited data and the radiological impact from the exposure to these radioactive elements is unknown. This paper describes the methodology that is being developed to assess the radiological impact due to the raise in the natural background radiation level originated by the release and dispersion of the emitted radionuclides. The current investigation is part of a research project that is undergoing in the vicinity of Sines coal-fired power plant (south of Portugal) until 2013. Data from preliminary stages are already available and possible of interpretation.

Le rayonnement ultraviolet est responsable d’un large impact sur les structures biologiques. C’est un carcinogène bien documenté. Alors qu’un certain nombre d’effets positifs peut être associé à ce rayonnement, les surexpositions induisent des effets aigus et chroniques sur la peau, les yeux et le système immunitaire. Les effets négatifs associés aux expositions peuvent être largement évités. Réduire les expositions au rayonnement UV par des modifications du comportement et de l’environnement constitue le but principal des mesures préventives. Longtemps considéré comme « innocent », le rayonnement UVA possède des propriétés mutagènes et carcinogènes qui sont aujourd'hui bien documentées et leurs mécanismes de production semblent aujourd'hui élucidés et en particulier la photochimie des UVA solaires dans la peau. Aujourd'hui, les mécanismes de la photocarcinogenèse induite par les UVA ou par les UVB paraissent identiques, leur importance étant égale dans le rayonnement solaire. Les efforts de prévention doivent s’adresser en priorité aux enfants mais également dans le cadre du travail, en particulier en extérieur. Des guides pratiques sont fournis par l’OMS pour aider les autorités sanitaires dans la mise en application d’une politique de prévention afin de réduire les risques associés au rayonnement ultraviolet.

Les enquêtes épidémiologiques, même celles portant sur plusieurs dizaines de milliers de sujets (comme chez les survivants d'Hiroshima et Nagasaki) ne décèlentpas d'effet cancérogène chez l'enfant ou l'homme adulte pour des doses inférieures à 200 mSv en irradiation aiguë ou 500 mSv en irradiation à faible débit. Alors que la dose due au rayonnement naturel varie entre 1,5 et 6 mSv et mêmeparfois davantage, les enquêtes n'ont pas pu déceler de variation dans la fréquence des cancers en fonction de cette irradiation naturelle. Ces résultats ne permettent pas d'exclure l'hypothèse d'un effet cancérogène des faibles doses maispermettent de fixer la limite supérieure de l'effet éventuel dans cette gamme de dose. Pour estimer celui-ci on se fonde donc généralement sur les effets observés à dose élevée en effectuant une extrapolation vers les doses faibles. En 1990 leCIPR a révisé à la hausse l'évaluation de l'effet cancérogène à dose élevée, principalement à cause de l'introduction d'un modèle mathématique destiné à estimer l'effet cancérogène jusqu'à la fin de l'existence des personnes irradiées. Lemodèle utilisé admet que l'irradiation introduit un facteur multiplicatif constant jusqu'au décès. Des résultats récents montrent qu'en réalité cet effet diminue avec le temps donc que cette hypothèse entraîne une surestimation du risque.Pour estimer les effets à dose faible le CIPR procède à une extrapolation linéaire assortie d'un facteur de réduction égal à deux. L'intérêt de cette méthode est d'indiquer la limite supérieure du risque mais elle peut surestimer notablementcelui-ci à faible dose. En effet cette proportionnalité de l'effet avec la dose même pour les doses et les débits de dose les plus faibles implique deux postulats : 1) l'efficacité de la réparation des lésions de l'ADN dans les cellules ne varie pas avec la dose et le débit de dose. 2) la traversée d'une seule cellule par une seule particule entraîne un risque de transformation cancérogène. Si ces hypothèsesétaient exactes le débit de dose ne devrait pas avoir d'influence pour les doses faibles mais ce n'est pas ce que montrent les données expérimentales. De plus lesrécents progrès faits dans l'étude des systèmes de réparation de l'ADN montrent qu'après de fortes doses ceux-ci peuvent être saturés et des systèmes de réparationmoins fidèles être mis en œuvre. D'autre part la cancérogenèse est un phénomène très complexe qui requiert plusieurs lésions indépendantes du génome qu'une seule particule est incapable de provoquer. D'ailleurs pour les particules déterminant la plus forte densité d'ionisation le long de la trajectoire de la particule (particules alpha) qui sont celles pour lesquelles il serait concevable qu'uneseule particule détermine plusieurs lésions, aucun effet cancérogène n'est observé pour des doses faibles en opposition avec les conclusions de ce modèle. Ainsil'effet cancérogène des faibles doses pourrait être notablement inférieur à celui qui avait été estimé en 1991. L'avancée rapide des connaissances tant pour lesmécanismes fondamentaux que pour les enquêtes épidémiologiques fait espérer que l'estimation du risque des faibles doses pourra dans les prochaines annéesêtre de plus en plus précise. Il est d'autant plus légitime de ne pas se hâter pour modifier les normes que moins de 1 % des travailleurs reçoivent actuellement une dose supérieure à la limite de dose annuelle actuellement proposée et que dansl'enquête du CIRC moins de 1 pour 1 000 des 90 000 travailleurs de l'industrie nucléaire étudiés n'avaient reçu au cours de leur vie professionnelle une dose avoisinant 1 Sv, dose limite-vie proposée à la fois dans les rapports de l'Académie des Sciences et du CIPR.

Cette note synthétise les données récemment acquises par l’IRSN ainsi que les données disponibles dans la littérature, concernant l’utilisation des isotopes de l’uranium pour évaluer les conséquences dans l’environnement des rejets des installations du cycle du combustible nucléaire. Ainsi, les végétaux peuvent témoigner d’anomalies du rapport de masse 235U/238U par rapport à la signature de l’uranium naturel (rapport de masse 235U/238U  =  0,72 %). De plus, les développements analytiques récents (ICP-MS) permettent de détecter 236U, traceur de rejets d’uranium de retraitement (URT) dans l’environnement de certains sites nucléaires. Enfin, la mesure du rapport d’activité 234U/238U en milieu aquatique, lorsqu’il révèle l’équilibre séculaire entre ces deux isotopes, est un traceur des rejets d’uranium provenant du traitement ou de la purification du minerai.

During the early phase of a large-scale accident with release of radioactivity to the atmosphere, it is essential to notify and inform competent authorities as early and as extensively as possible. Only when the accident is rapidly notified and information is continuously made available in the form of real-time monitoring data and dispersion forecasts are decision makers able to define appropriate countermeasures. The Chernobyl accident taught us that information exchange should be carried out in a harmonised and consistent manner. Although several European countries already had developed automatic monitoring networks by 1986 and in some cases established bilateral agreements to exchange this information, the size of the accident demonstrated the need to extend such schemes to the continental scale. It became important to have commonly agreed international data formats and procedures in place. Over the past 25 years, the European Commission has invested in improving the rapid exchange of information and data in the event of a major accident. For the early phase of emergency support, it has focussed on three closely related systems: the early notification system ECURIE, the automatic data exchange platform EURDEP and the atmospheric dispersion model exchange and evaluation system ENSEMBLE. Starting from the legal background, we describe these information systems in detail with an emphasis on their current status and their planned future developments.

The Yenisey River belongs to one of the main Siberian water systems flowing into the Arctic basin. Technogenic radionuclides have entered this system due to activities at the Krasnoyarsk Mining and Chemical Combine (KMCC), situated approximately 40 km downstream from the city of Krasnoyarsk (Zheleznogorsk), which began operations in August of 1958 (start-up of the first straight-through reactor, a second reactor was operated from 1961). In the period of 1958 to 1992 the river channel and flood plain were exposed to contamination at great distances downstream from the waste discharge point. Various long-lived radionuclides were measured in the environment such as 137Cs, 60Co, 152Eu, 154Eu with half-lives of 30.2, 5.3, 13.3 and 8.6 years correspondingly. Both reactors were decommissioned in 1992 and since then radionuclide discharges to the river have decreased by several tens of times.

In Finland, Olkiluoto Island has been selected for constructing a spent nuclear fuel disposal facility. With the approaching licensing step, submitting the application for nuclear construction licence in 2012, all components of the safety case are becoming more site-specific. In order to assess compliance with regulatory requirements, a prospective deterministic dose assessment methodology based on the ICRP concept of assessing doses to the representative person was developed and implemented in the interim safety case 2009, to be further refined for the safety case 2012. To facilitate the assessment of doses to the most exposed people and other people at the evolving site, full dose distributions are derived, comprising the dose to each potentially exposed person in each generation.

Oceans, seas, estuaries and rivers represent a vast sink for many substances of anthropic origin (metals, radionuclides, etc...). Depending on their chemical form, artificial radionuclides discharged into the sea by the nuclear industry can be carried onto land in marine aerosols, as well as by degassing seawater as is the case for tritium (3H) or for radiocarbon (14C). Three oceanographic cruises in the English Channel: TE-SEA, TRANSAT 1 and 2 have been performed on R.V. “Côtes de la Manche" to quantify the flux of 3H in gaseous form, from the sea into the atmosphere, following particular discharge into the sea from the COGEMA spent fuel reprocessing plant at La Hague (North West France). During cruises, the maximum concentration measured in the air was 10.6 Bq.L-1, which is distinctly higher than the background of 1$^{\circ}$Bq.L-1 thus demonstrating the transfer of 3H between water and atmosphere. The mean flux of 3H between the water and the atmosphere, calculated during these cruises was 2.4 107 Bq.km-2.d-1. For the Seine Bay area (4400 km2) this flux represents 39 TBq.yr-1 and hence less than 0.3 % of 3H discharged into the ocean from the COGEMA spent fuel reprocessing plant at La Hague.

Le site de Marcoule comprend une usine qui retraite le combustible irradié des réacteurs graphite-gaz et en extrait le plutonium. Une usine de fabrication du combustible MOX est en cours de construction. Ces activités sont génératrices d'effluents liquides rejetés au Rhône après traitement. Pour les émetteurs α, la réglementation en vigueur limite les concentrations de ces effluents à 150 GBq/an. Les rejets en plutonium et transplutoniens sont faibles (41 GBq en1989). Des mesures de plutonium ont été effectuées en 1989 dans certains compartiments de l'écosystème aquatique rhodanien en aval de l'usine. Au niveau du barrage de Vallabrègues (15 km au sud de Marcoule) on trouve les concentrations en 238Pu et 239 + 240Pu respectivement égales à 2,1 et 7,8 Bq.kg-1 sec dans les sédiments, 1,1 et 3,8 Bq.kg-1 sec dans les végétaux aquatiques immergés et égales ou inférieures aux limites de détection dans l'eau et les poissons. Dans les sédiments et les végétaux, le rapport 238Pu/239 + 240 Pu est d'environ 0,3. Les concentrations en plutonium des compartiments du milieu diminuent rapidement lorsqu'on s'éloigne de l'usine et sont inférieures aux limites de étection en Carmargue.