Presented studies were carried out during 1997–2007 within Krasnensky flood-lands on the left bank of the Pripyat River, which is the most contaminated region of the Chernobyl accident exclusion zone and where the complex of hydraulic engineering structures as flood protection dams was constructed, which preventing washing away of radioactive substances from soils and changing a hydrological mode of floodplain flows during a high water. In its turn it was by the reason of strengthening of over-moistening and swamping processes within embankment territories. As a result – on a background of the common tendencies of increase of the mobile forms of 90Sr in soils of catchment territories and bottom sediments of the exclusion zone, there is an increase of humic acids concentrations in waterlogged soils of Krasnensky flood-lands. It is also raises the content of the water-soluble forms of 90Sr forming with acids the soluble complexes. Thus the increase of concentrations of the mobile radionuclide forms and their inclusion into biotic circulation of aquatic ecosystems is observed. Such dynamics of 90Sr and 137Cs contents is significantly reflected on dose rate for hydrobionts due to incorporated radionuclides.

The activity concentrations of 226Ra, 232Th and 40K infifty granite samples collected from five different quarry industries in Ondo State,Nigeria, were determined using gamma-ray spectrometry. The mean activity concentrationsfor each industry ranged from 16.7(6.4) to 85.4(23.0), 62.4(10.1) to 113.6(7.6), and1315(136) to 1551(84) Bq.kg-1 for 226Ra, 232Th and40K, respectively. The values in parenthesis are the standard deviations.When compared with results from some parts of the world, the 226Ra and232Th contents were lower, whereas the 40K content was similar.Using different approaches to estimate the potential radiological hazard of the samples,the results obtained were below the recommended maximum limits. This shows that theradiological hazards associated with the use of the granites examined in this study asbuilding material are within the acceptable limit.

The European Basic Safety Standards Directive (EU, 1996) contains a chapter onintervention, which, to a large extent, is dedicated to emergency planning and response,but without detailed requirements. A new Directive will consolidate all existingDirectives and thus broaden the scope to all exposure situations and categories ofexposure, including the protection of the environment. This new text follows thesituation-based approach recommended by ICRP (ICRP, 2007). The requirements for emergencypreparedness have been worked out in more detail, and the use of reference levels foremergency response is highlighted. The accident in Fukushima prompted reflection on theEuratom legal framework, including the Basic Safety Standards, the arrangements for theearly exchange of information (ECURIE) and legislation on the nuclear safety of nuclearinstallations. A “stress test” of EU nuclear power plants has been undertaken, whichincludes on-site emergency response. The results of this exercise will allow theCommission to report, by the end of 2012, to the EP and the Council, and to propose newlegislation as appropriate. This may extend to the harmonisation of off-site emergencyresponse and communication arrangements among Member States. Meanwhile, an informalcoordination mechanism is being set up with the Heads of European Radiation ProtectionCompetent Authorities (HERCA). With regard to the legislation on maximum permitted levelsin food, there will be further reflection on the consistency between the controls in placeafter Chernobyl and after Fukushima, as well as their consistency with the values for theplacing on the market of food and feed in the EU in the event of a future accident.

Lors de la manipulation de radionucléides émetteurs β, les mesures en termesd’équivalents de doses individuels sous 0,07 mmHp (0,07) sont utilisées pour les comparerà la valeur limite en dose équivalente à la peau ou aux extrémités donnée par laréglementation. Dans un premier temps, des expressions analytiques pour les équivalents dedoses individuels sous 0,07 mm Hp (0,07) etles doses équivalentes aux extrémités Hpeau,dues au rayonnement β, sont données pour une source ponctuelle et une contaminationsurfacique sur la peau. Dans un second temps, les grandeurs opérationnelles et lesgrandeurs de protection sont comparées. Il est alors montré que dans le cas d’une sourceβ, la grandeur opérationnelle surestime de façon trop importante la grandeur deprotection. En effet, pour une contamination surfacique sur la peau le rapport entre lagrandeur opérationnelle et la grandeur de protection est de 2 pour une énergie maximaled’un spectre β de 3 MeV et de 90 pour une énergie maximale d’un spectre β de 150 keV.

Bien que le carbone-14 soit un radionucléide existant essentiellement à l’état naturel, sa présence dans l’environnement est souvent associée à la production d’électricité d’origine nucléaire. À l’occasion de la construction du nouveau réacteur EPR à Flamanville et des renouvellements réglementaires d’autorisations de rejets pour des sites existants, cette note a pour objectif de résumer la connaissance scientifique, les mesures réalisées autour des sites et les études d’impact dans l'environnement et chez l'homme pour ce radionucléide.

The CERES application (Code d’Evaluations Rapides Environnementales et Sanitaires) has been developed by CEA. It is used to evaluate the consequences on human health of releases of isotopes in the environment, either for emergency planning or for safety evaluation. Various types of emissions can be simulated: atmospheric accidental emission, atmospheric emission during normal operation or emission in liquid media under normal operation. Two versions exist, one devoted to radiological impact, the other one devoted to toxic impact.

The complex radioecological investigations of the East-Ural Radioactive Trace were conducted. Three transects were established in EURT area: central, eastern and western. The current levels of soil contamination near the epicenter of the accident reach 30 × 103 kBq/m2 for 90Sr and 1 × 103 kBq/m2 for 137Cs. Contamination levels are reduced in accordance with a power function with increasing distance from the accident site and at a distance of more than 100 km become close to background values. In the EURT impact area vegetation is a complex of synanthropic and semi-natural plant communities in various stages of degradation and restoration successions. The current state of phytocenosises on the sites of the demolished local villages is largely determined by the degree of human impact in the pre-accident period, and remediation activities. For most species the viability of their seed progeny, formed in a gradient of radioactive contamination, are either not different from background samples or reduced half a century after the accident. Mutability of seed progeny in impact coenopopulations in all studied species was high. Radioadaptation phenomenon, i.e. increased resistance to provocative irradiation is rare and unstable.

Aerosol dry deposition onto agricultural and forest areas is investigated. Its estimation is still uncertain, particularly for rough surfaces and sub-micronic aerosols. In fact models used in radiological risk or air quality assessment studies are highly empirical and fail to reproduce the results of the most recent measurement campaigns. Therefore a theoretical framework, based on a mechanistic description, has been developed. The proposed approach consists in two steps. First, interaction between aerosols and foliar surface is formulated by using a set of parameters, which are defined on the local scale of one foliar element. In the second step, the collective effect of the foliage is taken into account through statistical distribution of these parameters. The model integrates the three main factors governing aerosol dry deposition. These are local aerodynamic characteristics of the flow within the canopy, aerosol mechanisms governing the deposition, and canopy structural and morphological properties. Physical processes considered in the study are inertial impaction, gravitational settling and Brownian diffusion. The canopy characteristics considered are spatial distribution, orientation and micro-structure of foliar surfaces. The applicability of the model is demonstrated on an existing measurement campaign.

Tritium (3H) transfer into environment must be modelled differently than the transfer of other radionuclides released from nuclear reactors because hydrogen represents the building blocks of life. A solid understanding of 3H behaviour is essential because 3H may be released in large quantities from CANDU (CANada Deuterium Uranium) reactors and from future thermonuclear reactors. Recently, the authors published a complex dynamic metabolic model for 3H and 14C transfer in farm and wild animals, but the model applications for wild biota were restricted to too few examples and mostly for 14C transfer. In this study, the model is applied to few selected wild animals for 3H uptake. Despite the lack of any experimental data for wild animals, the results presented in this study are less uncertain than for many other radionuclides and can provide a useful estimation for biota radioprotection.

Several radioactive particles from the Palomares area have been analyzed with the nuclear microprobe of the National Accelerator Centre (CNA) in Seville exploring the advantages of combining µ-PIXE using a 5.5 MeV 4He beam with conventional µ-PIXE analysis using 3 MeV protons. The measurements performed with the α-particles are more sensitive to the sample surface, while the results collected with protons are indicative of the average composition of the hot particle. In this way, important information about the depth distribution of Pu and U in the particles has been obtained. In addition, the particles have been analyzed by SEM (EDX) and one of them has been sacrificed for the determination of its U and Pu isotopic composition by ICP-MS and α-spectrometry, being gained in this way important information about the composition of the weapons involved in the Palomares accident.

The transfer of transuranium element americium-241 (241Am) from food and water to organs and tissues of freshwater fish (Carassius auratus gibelio, crucian carp) has been investigated in laboratory experiments. The fishes were fed with homogenized biomass of submerged macrophytes labeled with 241Am, through catheter. For the first two days after force-feeding, fishes excreted up to 80% of ingested americium, for four days – 98%. 241Am was registered in internal organs and tissues that had no direct contact with americium (liver, bones, muscles) as early as two days after the feeding and after eight days, when the digestive tract was depurated. Among internal organs, the highest activity concentration was recorded in the liver (up to 427 Bq/kg). Activity concentration in bones (19–31 Bq/kg) was several times higher than in muscles, indicating the affinity of americium to bone tissue. Assimilation of 241Am in organs and tissues of crucian carp from water occurred mainly via the digestive tract too.

Two handbooks have been developed in conjunction with a wide range of stakeholders thatprovide assistance in the management of contaminated food production systems and inhabitedareas following a radiological incident. Emergency centres in Member States not involvedin the development of these handbooks were invited to take part in demonstrationactivities to establish whether the handbooks would be useful for the purposes ofcontingency planning and accident management. Some eight centres took part. Emergencyexercises or similar events based on scenarios involving contamination of the foodchainand inhabited areas were used. Feedback from all of the demonstrations was positive withconstructive criticism given on how to improve the navigation, structure and format of thehandbooks. All of the key improvements highlighted during the demonstrations were takeninto account and included in version 2 of the handbooks. Two additional demonstrationstook place in Denmark and Slovakia to investigate the appropriateness and applicability ofa stakeholder participatory process when applying the handbooks. These stakeholdersexpressed their willingness to discuss the issues at stake from contamination of foodproduction systems and inhabited areas and gave a clear commitment to continue theprocess.

La directive 96/29/Euratom a identifié le thermalisme comme étant une activité professionnelle pendant laquelle les travailleurs sont exposés à des sources naturelles de rayonnement. En effet, la radioactivité des eaux minérales est en relation directe avec la nature géologique des roches traversées par ces eaux tout au long de leur périple jusqu'à la surface. Elle se charge en divers radioéléments et notamment en radon. Les valeurs d'activité volumique de radon mesurées dans les eaux thermales françaises et étrangères s'échelonnent de la centaine à plusieurs dizaines de milliers de becquerels par litre d'eau. De par l'utilisation qui en est faite lors des soins thérapeutiques, le radon dissous dans l'eau thermale se retrouve par dégazage dans l'atmosphère intérieure des différents locaux des stations thermales. Selon le type de soins pratiqués, l'activité volumique du radon dans l'air est très variable ; elle est tributaire de deux facteurs, l'alimentation en eau thermale et donc en radon et la ventilation des différents locaux. Elle est de l'ordre de plusieurs milliers de becquerels par mètre cube d'air dans les salles d'hydrothérapie et peut atteindre la centaine de milliers de becquerels par mètre cube d'air dans certaines grottes thermales. Sur ces bases, des évaluations dosimétriques, issues d'études étrangères, montrent que l'exposition des travailleurs peut atteindre plusieurs dizaines de millisieverts par an. Les rares études françaises traitant de ce sujet montrent des niveaux d'exposition au radon des travailleurs du même ordre de grandeur, démontrant ainsi la nécessité de considérer le radon comme une source importante d'exposition dans les établissements thermaux.

Les enquêtes réalisées par les “médecins nucléaires” avec l'ANDRA pour caractériserles déchets radioactifs hospitaliers ont conduit à proposer des améliorationsde la gestion de ces déchets. On peut citer, au nombre de ces propositions: l'amélioration du tri sur les lieux de production par rationalisation desprocédures de collecte, l'organisation in situ d'un stockage en décroissancepour les déchets contenant de l'iode 125, l'éducation systématique des personnelshospitaliers concernés, notamment pour parer aux risques infectieux, l'obtentionpar voie législative d'un déclassement des déchets tritiés et carbonéshospitaliers, ainsi ramenés à des déchets banalisés.La mise en œuvre de ces mesures, au niveau de l'hôpital, par la “personnecompétente” en radioprotection devrait affranchir les services hospitaliers durecours systématique à l'ANDRA et générer ainsi des économies importantes.

Radio-caesium is an important radionuclide released considering food and feed products. In aquatic environments caesium tends to accumulate in fish, both through its diet and its gills. This presentation discusses the caesium accumulation in fish living in estuaries. The aim of this work is to conclude on the importance of potential uptake routes: via the gills, diet or ingested with water. It is suggested that the magnitude of caesium accumulation in fish is related to waterborne potassium concentrations. Based on this theory, fish living in seawater should show a suppressed caesium accumulation compared to fish that stays in freshwater. However, to compensate for water losses, seawater fish are constantly drinking, adding an alternative route of entry for caesium. Apart from these two possible uptake routes of waterborne caesium, fish may take up caesium via their diet. Separate uptake-and-elimination studies were performed to measure the waterborne and dietary caesium uptake and elimination rate constants in fully acclimated Sea Bass at six different salinities (ranging from 1‰ to 35‰). Short-term uptake studies were performed as well to evaluate the effect of the waterborne potassium concentration. A toxicokinetic model evaluated several scenarios to conclude on the importance of each uptake route.

The cytogenetical effects of long-term irradiation in embryo tissue of gastropod snail (Lymnaea stagnalis L.) as chromosome aberration rate as well as change of structure, level of differentiation, death and cytogenetical stability of hemolymph cell population has been studied. Our researches were carried out during 1998–2007 in water bodies within the Chernobyl Exclusion. The absorbed dose rate for snails from research water bodies within the exclusion zone was registered in the range from 1.8 mGy/year to 3.4 Gy/year. The highest rate was found in snails from lakes, the lowest – from the river ecosystems. Molluscs from the control lakes were characterized by absorbed dose rate about 0.3 mGy/year. The lowest rate of chromosome aberration was determined in molluscs form the control lakes – 1.1–2.0%. The highest rate was found in snails from lake ecosystems – 21–23%. In hemoliph of snails from contaminated lakes of the exclusion zone the quantity of death cells averages 40%, the part of phagocytic cells averages 42% as well as decrease of the young amoebocytes quantity to 10–20.1%. In the control water bodies the part of death cells averages from 2.2 to 5.3% and the quantity of phagocytic was at level 3.0–4.2%. The quantity of young amoebocytes have useful increased here to 79.7–89.6%.

Des quantités allant de 1 à 20 fois les LAI pour l'uranium (sous les formes chimiques UO2 et U3O8) ont été inhalées par des babouins suivis pendant 1 an par anthroporadiométrie puis sacrifiés pour analyse des différents organes où l'uranium peut migrer en quantité significative. Les résultats ont montré qu'un an après : 1) la rétention d'uranium dans le poumon est plus forte lorsqu'il est inhalé sous forme d'UO2 que sous forme d ' U3O8 ; 2) le rapport “concentration dans les ganglions/concentration dans les poumons” est plus élevé lorsque l'uranium est inhalé sous forme d'UO2 ; 3) pour les deux formes, le transfert vers les ganglions n'est pas influencé par la massé inhalée ; 4) les concentrations relatives d'uranium, quelles que soient les formes inhaléesévoluent dans l'ordre : ganglions thoraciques › poumons ›› crâne › fémurclavicule › vertèbres lombaires – cage thoracique › sternum › reins › foie ; 5) la mesure de certains enzymes présents dans les urines peut être utile poursurveiller les surexpositions d' U3O8, mais, à ce jour et dans la gamme de doses étudiée, l'anthroporadiométrie et l'excrétion urinaire restent des procédés de choix.

S'il n'y avait pas eu un gaz (le radon) au milieu de la famille radioactive de l'uranium, la radioactivité naturelle n'aurait posé aucun problème sanitaire. Plus rare, le gaz thoron, son isotope, estnégligé par la législation, mais ses descendants peuvent parfois devenir dangereux, souvent à cause de certains matériaux de construction. Les "Détecteurs Solides de Traces Nucléaires"(DSTN) enregistrent les impacts individuels des particules alpha, sans perturber le milieu. Ces DSTN sont des plastiques, sélectionnés pour leur sensibilité aux particules alpha. Un simpletraitement alcalin permet d'agrandir, de visualiser, donc de compter les traces obtenues. Placés dans de petits boîtiers passifs, ils deviennent des dosimètres bon marché, pour la mesure intégréedu radon et l'évaluation du risque sanitaire. Une examen pratique montre que tout n'est pas si simple. Le choix d'un dosimètre "ouvert" (DSTN à l'air libre) ou "fermé" (DSTN dans un boîtier) estdiscuté. Les différences pratiques sont expliquées par l'examen du passage progressif d'un dosimètre "ouvert" à un dosimètre "fermé". Indépendamment de la facilité d'emploi, pour une meilleureestimation globale du risque naturel, mieux vaudrait mesurer "ouvert", tandis que pour les mesures relatives aux sciences de la terre, mieux vaudrait mesurer "fermé". Le débat, lui, est ouvert.

During 2001–2002 we investigated current contamination of soils in several places in the Chornobyl zone. We have measured the content of alpha emitting isotopes Pu, 241Am, 154,155Eu, 90Sr, and 137Cs in layers of soil up to the depth of 30 cm. By including the two mechanisms of migration: convection and diffusion in our model, we were able to estimate the ecological and effective half-lives of self-purification processes for these layers of soil. Effective half-lives vary from 20 to 400 years dependent upon the type of soil and the isotopes.

The ERMIN model is a new implement developed to enable estimation of the radiologicalconsequences in inhabited areas of accidents in nuclear installations. Similarly, AGRICPis a model developed to enable estimation of the radiological consequences ofcontamination of agricultural production areas. This paper provides a short overview ofthe background of the two models and describes the features enabled through theirimplementation in the ARGOS decision support system. The integration allows calculation ofboth dose rates and doses in particular areas, and can be used to evaluate theeffectiveness and costs of countermeasure strategies.