Un important programme de recherches, appelé « Generation IV », est actuellement développé au niveau international pour préparer les réacteurs du futur et leurs « cycle de combustible ». Son objectif est de satisfaire les besoins croissants en énergie électrique dans le cadre d'un développement durable. L'un des aspects majeurs de ce programme est la recherche et le développement de nouveaux matériaux nucléaires fissiles/fertiles. Malheureusement, on s'aperçoit aujourd'hui que, pour de nombreux composés candidats pour développer ces matériaux, il n'existe pas de données radiotoxicologiques permettant au médecin du travail d'évaluer le risque réel en cas de contamination et de prescrire un traitement de décontamination adapté. Il conviendrait donc de relancer d'urgence les études de poste où sont, ou bien seront, mis en œuvre ces composés ou matériaux. L'expérience passée a montré que la prévision en matière de radioprotection était difficile et qu'une validation expérimentale du comportement des éléments lourds radiotoxiques ou toxiques in vitro et in vivo était nécessaire.

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.

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.

La Commission Internationale de Protection Radiologique (CIPR), dans ses nouvelles recommandations, propose l'utilisation de paramètres déterminés expérimentalement pour effectuer uncalcul de dose efficace par unité d'incorporation (DPUI) spécifique pour chaque composé. Le but de cette étude est de définir une méthodologie (techniques d'analyse, test in vitro de dissolutionet test in vivo sur rats) permettant d'accéder à ces données et de présenter les méthodes de calcul utilisées, comme le logiciel GIGAFIT pour l'interprétation des données de transfert sanguin, etle logiciel LUDEP pour le calcul de dose. Ce travail a permis de déterminer pour un composé UO2 (uranium appauvri), utilisé dans la fabrication du combustible MOX, les principaux paramètresphysico-chimiques et biologiques qui entrent dans le calcul de dose : le Diamètre Aérodynamique Médian en Activité ou DAMA de 6,5 microns; la Surface Spécifique SS= 2,68 m2.g-1; et lesfraction et taux de transfert sanguin respectivement fr, entre 2,5% et 44,4%, Sr, entre 0,09 et 1,7 j-1, et Ss, entre 6,4x10-4 et 1,5x10-3 j-1. Ces résultats intégrés dans LUDEP conduisent à une DPUI spécifique par inhalation pour ce composé UO2 égale à 2,84x10-6 Sv.Bq-1.

Dans la première partie de cette revue, nous avons examiné, au travers d’une étudebibliographique approfondie, l’influence de différents facteurs liés à l’individu (âge,sexe, consommation d’alcool ou de tabac) sur le taux de translocations. Dans cette secondepartie, notre revue de la littérature s’est attachée à l’étude de facteurs plus toxiquesliés à une exposition professionnelle. Tous les agents toxiques analysés induisent uneaugmentation du taux de translocations au sein des lymphocytes des personnes exposées.Cependant 2 agents (hydrocarbures aromatiques polycycliques –HAPs- et les métaux lourds)augmentent de manière significative le taux des translocations des personnes exposées. Cetype d’agents toxiques augmente le taux de translocations proportionnellement à la dose età la durée d’exposition. La sensibilité de la technique FISH a permis de mettre enévidence la nécessité et le bon fonctionnement des équipements de protection. Pour tousles facteurs toxiques liés à une exposition professionnelle, un équipement de protectionadapté et ergonomique ou bien la période d’exposition ont réduit significativement le tauxde translocations des individus exposés. Ainsi la technique FISH pourrait servird’indicateur d’exposition. En conclusion, afin d’évaluer rétrospectivement l’expositiond’un individu, il est important de connaitre le plus précisément possible son curriculumclastogène et son âge. Ainsi, un taux de translocations limite pourrait être établi enfonction de l’impact des expositions professionnelles et environnementales connuesaujourd’hui et de la connaissance du passé de l’individu.

The natural radioactivity due to presence of 238U, 232Th and 40K in zirconium minerals used in the Iranian ceramic industry, tiles and waste sludges has been measured. The measurements were made by gamma spectrometry system with a high pure germanium (HPGe) detector connected to multichannel analyzer (MCA). The average concentrations of 238U and 232Th determined in the mineral samples (3000, 500 Bq kg-1 respectively) are much higher than concentrations found in the earth's crust. The specific activity of 238U and 232Th in tiles (62,54 Bq kg-1 respectively) are not higher than in other building materials.

The 238U concentration of sludges (150 Bq kg-1) is higher than the mean value for the earth's crust. The results are examined on the basis of the existing national limit.

In this study, the effects of 99Tc discharges from Sellafield to the Irish Sea on activity concentrations in fish and shellfish landed at ports on the north-east coast of Ireland and the resultant committed effective doses to typical and heavy consumers of seafood since 1990 are presented. Technetium-99 activity concentrations in fish and shellfish from the Irish Sea increased in the mid-1990s in line with increased discharges from Sellafield. In 2003, 99Tc discharges were reduced and have now returned to the levels of the early 1990s. Although there has been a reduction in 99Tc activity concentrations in fish and shellfish landed at ports on the north-east coast of Ireland, the dose to Irish seafood consumers has not returned to the baseline levels of the early 1990s, being greater by a factor of two. In 2006, 99Tc accounted for approximately 15% of the total dose (0.16 and 0.75 µSv for typical and heavy consumers, respectively) to Irish seafood consumers from all artificial sources of radioactivity in the Irish Sea.

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.

The Radiological Protection Institute of Ireland has monitored levels of anthropogenic radionuclides in the Irish marine environment for over 20 years. While the primary objective of the monitoring programme is to assess the exposure of the Irish population resulting from the presence of these radionuclides in the marine environment, the programme also aims to assess the geographical distribution and temporal variations of the radionuclides. The programme involves the routine sampling of and testing for radioactivity in fish, shellfish, seaweed, sediments and seawater. The data generated in the course of this programme, as well as in a separate study of changing plutonium isotopic ratios in Fucus vesiculosus from the west coast of Ireland, were used to estimate transport times from the Sellafield nuclear fuel reprocessing plant to various locations on the Irish coastline. For conservative radionuclides, transit times of 5-6 months to the NE coast of Ireland, 1-3 years to the south coast of Ireland and 3-8 years to the west coast were calculated. In contrast, for plutonium, the Sellafield signal was not observed on the west coast until the late 1980s/early 1990s.

Assessment of the future radioactive environmental contamination threat by releases from dumped submarine and ship reactors with Spent Nuclear Fuel (SNF) is a project goal. The methodology of detection of traces of 85Kr and 3H (which the first are leaking from the SNF) in sea water is advanced. Search of ship nuclear reactors on a bottom in dumpsites on 85K plume is proposed. Investigation of releases from the dumped ship reactors with SNF of icebreaker “Lenin" in Kara Sea is launched (September 2003). Research has complex character: experiments with SNF, creation of techniques located on R/V “Ak. B. Petrov" and expedition works. Preliminary observation of hydrological characteristics in zone of marked dumpsites has been fulfilled. The first results on the 85Kr concentration in near-bottom layer of Kara and the Barents Seas also Tritium and Radiocesium during August 2003 were obtained.

The TOCATTA model simulates 14C transfer within terrestrial and/or continental water ecosystems, in response to chronic and accidental hypothetical emissions of 14C, in a liquid and/or gaseous form. This model has been developed from bibliographical knowledge on C cycling and common hypothesis to existing 14C transfer models, in order to come within the conceptual and mathematical frameworks of the SYMBIOSE project. In this context, the conceptual modelling deals with discretizing the continental biosphere into elementary components likely to be contaminated and identifying interactions or transfer processes of 14C between two components. The mathematical modelling for calculating stocks and fluxes under accidental conditions is based on a system of differential equations expressing conservation of pollutant activity for each component of the conceptual model. It is shown that the analytical solutions obtained when temporal derivatives of the differential equation system are equal to zero correspond to the activities at “steady-state" simulated for chronic contaminations.

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.

Accidental exposure to ionising radiation may occur during such catastrophic events as the Chernobyl accident in 1986 or for days and weeks as in Goiania in 1987 and in the military camp during the training of soldiers in Lilo/Georgia in 1997 as well as in medical institutions. The cutaneous symptoms after radiation exposure are based on a combination of inflammatory processes and alteration of cellular proliferation as a result of a specific pattern of transcriptionally activated proinflammatoric cytokines and growth factors. They follow a time course consisting of prodromal erythema, manifestation, chronic stage, late stage and they are referred to as Cutaneous Radiation Syndrome. The time course depends on several factors such as the applied radiation dose, radiation quality, individual radiation sensitivity, the extent of contamination and absorption and volume of the skin. For diagnostics of the cutaneous radiation syndrome the following procedures are used: 7.5 MHz to 20 MHz-B-scan-sonography, thermography, capillary microscopy, profilometry, nuclear magnetic resonance imaging, bone scintigraphy and histology. Based on the results of experimental and clinical research of the last years pharmacotherapy of the cutaneous radiation syndrome includes topic or systemic application of corticosteroids, gamma-interferon, pentoxifylline and vitamin E and superoxide dismutase. The treatment depends on the stage of the cutaneous radiation syndrome. Due to the complexity of the clinical manifestations of radiation disease in most patients an interdisciplinary treatment in specialised centres is necessary. Dermatologists are asked to perform in most cases life-long therapy and follow-up of the patients.

The naturally occurring radionuclide 210Po was determined in different components of the Black Sea ecosystem. The specific activity of 210Po in water in the open part of the sea was about 1Bq ⋅ m-3. The range of 210Po specific activity in bottom sediments was 4.5–500 Bq ⋅ kg-1 dry weight depending on their type, area and depth of collection. The highest values were found in the NW part of the Black Sea. Sediment distribution coefficients (Kd) of 210Po for bottom sediments, calculated on a dry weight basis, varied from 0.5 × 104 to 5 × 105. The levels of 210Po specific activity in molluscs and pelagic fishes anchovy and sprat were the highest among the investigated species of the Black Sea biota. Concentration factors (CF) of 210Po, estimated on a wet weight basis, reached 1.5 × 103 for macrophytes, 4 × 103 for total zooplankton, 103–104 for the entire fishes depending on their ecological groups affiliation and (0.7–6.0) × 104 for molluscs. So, the ability of the Black Sea biota to accumulate the natural radionuclide 210Po is comparable with that of similar species from others marine and oceanic areas.

Environmental radioactivity in Greenland and the Faroe Islands was investigated from samples collected in 2004 of seawater, seaweed, marine fish, seal, whale, lake water, freshwater fish and total diet. Anthropogenic radionuclides in Greenland and the Faroe Islands are present due to long-range transport by air and water mainly due to fallout from nuclear weapons testing, from the Chernobyl accident and discharges from European reprocessing facilities, Sellafield in the UK and La Hague in France. Concentrations of anthropogenic radionuclides in environment and food are low, however, and present insignificant health risks to humans. Naturally occurring radionuclides are present in the environment and human food and dominate the radiation dose from ingestion. Even in case of landlocked Arctic char from South Greenland showing elevated concentrations of anthropogenic 137Cs, the radiation doses to man from ingestion derive mainly from the presence of the naturally occurring radionuclide 210Po. Samples of total diet from Uummannaq indicate that annual radiation doses by ingestion could approach 1 mSv from 210Po possibly due to a high proportion of seal flesh and liver in the diet.

Depuis 1990, plus de 400 cancers de la thyroïde ont été observés chez l'enfantdans le Sud de la Belarus et dans le Nord de l'Ukraine. L'importance de l'augmentationde l'incidence, l'agressivité de ces cancers et leur découverte fréquenteà un stade métastatique rendent mineur le rôle du dépistage. Plusieursarguments plaident en faveur de la responsabilité de l'accident de Tchernobyl :1) l'importance de la contamination initiale ; 2) la distribution géographique,l'augmentation de l'incidence étant observée au niveau des régions les pluscontaminées ; 3) la distribution temporelle, l'augmentation de l'incidence étantprogressive depuis 1990. L'iode 131 est vraisemblablement l'agent responsablede cette augmentation. Ces données renforcent l'importance de la prophylaxiepar l'iodure de potassium de l'irradiation de la thyroïde en cas d'accident decentrale nucléaire, notamment chez les enfants où elle est pratiquement sansdanger.

Cette étude a pour objectif principal de répondre à la question de savoir qui de l’approche de Smoluchowski (loi de diffusion et loi de probabilité) ou de l’équation de diffusion (∂Ci/∂t = Di∇2Ci + S) est plus appropriée, en termes de facilité de mise en œuvre et de réduction de temps de calcul machine, lorsqu’il s’agit de traiter la phase chimique de diffusion et de réaction des radicaux libres crées 10-12 seconde après l’irradiation d’un fragment d’ADN linéaire hydraté, par des électrons incidents d’énergie comprise entre 100 eV et 10 keV. Il est tout à fait clair, que cette comparaison repose sur les résultats de la simulation des étapes physique et physico-chimique par la méthode de Monte Carlo du type « au coup par coup ». En effet, deux logiciels relatifs à chaque approche sont mis au point, et nous permettent de déterminer les rendements des principales espèces radiolytiques (e-aq, H, OH), les rendements des cassures simple et double brin de la molécule d’ADN. Le temps étant la principale variable, l’énergie des électrons incidents, le degré d’hydratation µ des sous unités de la molécule d’ADN sont utilisés comme paramètres pour accentuer le degré de comparaison des deux méthodes.

The environmental monitoring of waste heaps, sludge reservoirs is an important task. The Pb(Po) accumulation of tobacco has been known for long. Knowing familiar with the accumulation capability can be suitable for bio-monitoring the tailing ponds of the remedied uranium mine, as isotopes may be bound on the skin surfaces or may be absorbed via the roots.

Our research investigates the Pb(Po)-210 concentration values of tobacco plants grown for experimental purposes in the remedied uranium-mine area. During the work the Pb(Po)-210 concentration values of 73 tobacco and soil samples, grown between 2002-2009 were determined using a semi-conductor (PIPS) detector alpha-spectrometer. The source for measurement was prepared using spontaneous deposition process following the combined acidic leaching using Po-209 tracers. Based on the results it can be stated that the Pb(Po)-210 activity concentration values of tobacco and soil samples altered between 2.12 ± 0.8 – 1866 ± 98 mBq/g. Processing the measurement data of the previous years it was apparent that with the changes of the Pb(Po) concentration values of the soil samples the activity concentration values of the tobacco samples also changed proportionally. Therefore, later the migration of radioisotopes disengaged from the tailings dump can also be traced.

Le service de santé au travail du CEA/CADARACHE est un service médical de site chargé de la surveillance radiologique de l’exposition interne de l’ensemble du personnel travaillant sur le centre de Cadarache. Dans son activité spécifique de surveillance du risque radiologique prédomine la gestion des expositions aux transuraniens (plutonium et américium), avec environ 400 salariés concernés. Nous avons mis en place depuis 2002 une surveillance systématique de ce risque d’exposition par des analyses radiotoxicologiques des selles. Nous présentons ici notre retour d’expérience sur les trois premières années.

Results of laboratory, “green-house" and long-term field experiments carried out on different plant species (spring barley, Scots pine, bulb onion and others) to study ecotoxical effects of low doses and concentrations of such common environmental factors as acute and chronic g-radiation, heavy metals, pesticides, artificial and heavy natural radionuclides, are presented. Special attention is paid to ecotoxic effects of chronic low dose exposures, synergistic and antagonistic effects of different factors' combined action. The results of long-term field experiments in the 30-km Chernobyl NPP zone and in the vicinity of a radioactive wastes storage facility are discussed. The data presented suggest that the further evolution of investigations in this field would issue in the development of a theoretical bases and practical procedures for environmental protection against radioactivity, taking into account the new experimentally confirmed facts about the presence of such essentially important singularities as the nonlinearity of a dose-effect relationship, radiation-induced genomic instability, phenomenon of radioadaptation, increased probability of synergetic and antagonistic effects of the combined action of different nature factors.