Institute for Radiation Protection and Nuclear Safety (IRSN)
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A brief overview of on-going multi-level studies of radionuclides toxicity at LECO
No full textInternational audienc
The Epidemiology of Lung Cancer Following Radiation Exposure
No full textInternational audienceEpidemiological studies of occupational, medical, and environmental exposures have provided important information on lung cancer risk and how those risks might depend on the type of exposure, dose rate, and other potential modifying factors such as sex and age of the exposed. Analyses of data from underground miner cohorts and residential case-control studies provide convincing evidence that radon is a leading cause of lung cancer. For low-LET radiation, risk models derived from results from the Lifespan Study of Japanese atomic bomb survivors suggest that for acute exposures, lifetime attributable risks for lung cancer are greater than for other specific cancer sites and are substantially larger for females than males. However, for protracted and fractionated exposures other than from radon, results from epidemiological studies are seemingly often contradictory.This report includes summaries of oral presentations during a symposium on radiogenic lung cancer risk given by a panel of experts on October 5 during the Radiation Research Society’s 67th annual meeting. This session included presentations on: 1) the largest pooled study of male uranium miners (PUMA) exposed to radon; 2) the most recent analysis of the Canadian Fluoroscopy cohort featuring state-of-the-art dosimetry for radiation exposures associated with frequent medical diagnostic procedures; 3) an update from the Million Person Study on risks from fractionated occupational exposures, and 4) studies of second primary malignancies – including lung cancer – in patients who had been treated for thyroid cancer
Impact of γ-radiation on carbon steel anaerobic corrosion and H2 production.
No full textInternational audienceThis article reports investigations on the anoxic corrosion process impacting a carbon steel/ultrapure deaerated water system when it is exposed to gamma radiation (50 Gy h), and on the associated molecular hydrogen gas generation. On the one hand, a dynamic semi-open experimental setup allowing to distinguish between the H production related to water radiolysis and the one related to anoxic corrosion has been adopted to estimate the corrosion rate associated to three successive temporal phases: pre-irradiation, irradiation and post-irradiation phases. On the other hand, post mortem analyses performed on both liquid and solid samples permitted to (i) quantify the chemical changes occurring in solution due to the formation of water radiolysis products and (ii) observe and characterize the thin corrosion layer composed of magnetite (FeO) at the surface of the metallic coupons. We show that gamma radiation induces a slight diminution of the carbon steel corrosion rate. However, by comparing the mean corrosion rate values obtained for the three studied phases (i.e., before, during and after irradiation), the chemical changes caused by radiolytic species seem to inhibit the formation of a thick magnetite protective layer. Additionally, the corrosion rate observed in post-irradiation phase does not decrease over time, which suggests that irradiation could modify the properties of the corrosion product layer by making it less protective. A structural modification of this oxide film might be caused by the oxidizing water radiolysis products. Such mechanisms may favour continuous active corrosion processes rather than passivation of the metallic surface and thus lead to a reduced lifetime of the component
Assessment of U and Th (bio)availability within a former U mine-impacted wetland
No full textInternational audienceAssessment of the impact of naturally occurring radionuclides (NOR) within terrestrial biotopes of uraniferous territories is a sound issue. Among others, it requires deep understanding of NOR transfer within the soil-water-microorganisms/plants continuum. In this study, part of RADONORM (european-funded) and Needs-Environment INSPECT projects, we combined in-situ and lab characterization of samples taken from a small wetland downstream a former U-mine (Rophin site, France). Soil cores and co-located plants (Caltha palustris, Scirpus sylvaticus) were sampled in 2 zones, where a layer of U-rich materials originated from decantation pound leakage is present or not (control) in the root-colonized horizons. Samples were characterized for U and Th contents. Environmental availability and bioavailability were assessed in some soil layers respectively by successive batch desorption and by the ISO normalized RHIZOtest with ryegrass as test plant.U has an heterogenous distribution within the soil profile with higher concentration in the U-rich materials layer. In situ-U Transfer Factors ([U]leaves/[U]soil) were not different between the 2 zones despite contrasted soil and plant concentrations. For Th, plant concentrations and TF values were lower in the control zone than in the impacted one despite similar concentrations in soil. Environmental availability of U (0.3 to 3%) and Th (<0.1%) was low in all soil layers, with higher values in organic surface horizons of both zones for Th. These values differ from those of bioavailable U and Th assessed by the RHIZOtest experiments. The latter are lower than the environmental available ones for U in the mine layer and in organic layers for Th, whereas the opposite is observed for U in both horizons of the control zone and for Th in the deeper horizons of both zones. Results highlight the complex link between element speciation, solution/root relationships and transfer intensity and illustrate the remaining challenge to link availability/bioavailability experiments
Comparative Analysis of 1D and 2D Tools for the Modelling of the Dispersion of Liquid Discharges in Rivers
No full textInternational audienceThe modelling of the dispersion of liquid discharges in rivers relies heavily on the selection of appropriate models (hydrography, hydraulics and dispersion) in regard of the situation (normal operating conditions, crisis, case of expertise…) and operational criteria such as available data, calculation time and required precision. To ensure the best choice for a given case, this research aims to compare and characterize the optimal application areas of three modelling tools available at IRSN by considering their suitability for routine assessment (monitoring, site expertise, etc.) and accidental scenarios (situation assessment, decision support…), as well as their performance and operational constraints, including data requirements and response times. The tools compared are a 1D dynamic model (SYMBIOSE, developed at IRSN and co-owned by IRSN and EDF), a 2D analytical approach in steady-state conditions (CASTEAUR2D, developed at IRSN) and a numerical 2D model (TELEMAC 2D, originally applied by IRSN for flood risk assessment). The study focuses on the downstream of the Dampierre-en-Burly nuclear power plant (NPP) located on the Loire River, 50 km upstream from Orléans, which is already used as an application area for the TELEMAC 2D model at IRSN. To identify the privileged application domains of these tools, they are applied and compared on the base of in situ tritium activity concentrations measured in the Loire River by EDF during routine discharges of the NPP for low and medium flow rate conditions of the river and completed by an hypothetical case for high flow rate conditions. It can be concluded that SYMBIOSE excels in quick response but has limitations as it only provides mean activity concentration and maximum activity concentration values. CASTEAUR 2D offers accessible setup but simplifies river geometry. TELEMAC 2D provides authentic 2D data but demands more computational resources and expertise
Handling confounding factors in analyzing the transcriptomic data from Chornobyl tree frogs
No full textInternational audienceMore than 30 years after the nuclear power plant accident in Chornobyl, wildlife in the Chornobyl Exclusion Zone (CEZ) is still chronically exposed to low doses of ionizing radiation. In 2018, populations of the Eastern tree frog Hyla orientalis were sampled inside the CEZ across a gradient of radiocontamination and in nearby control sites. Our research project aims at developing methods for multi-omics data integration to advance the understanding of the consequences of chronic exposure to low-dose radiation. The first axis of this study focuses on the exploration of transcriptomic data in relation to dosimetry. The analysis of RNA-seq data could reveal radiation-specific molecular signatures; however, this can only be accomplished if confounding factors are properly accounted for. Here, we compare batch effect removal strategies using the transcriptomic data obtained from 87 tree frogs. We highlight the strengths and weaknesses of the following methods: the ComBat-seq method dedicated for RNA-seq count data, linear regression on the batch with residuals extraction, and an integrated approach with mixOmics MINT. The geographical site of origin of the frogs is a confounding factor for the analysis, and its complete confoundedness with the dose makes its handling challenging. Indeed, the different methods we used were brought to their limits: correcting or accounting for the batch effect cuts out the biological information related to the dose. The site factor encompasses hidden information, including the local environment and available food sources, the day of capture, and the genetic diversity between the populations of tree frogs. In a second approach, we performed hierarchical clustering on the genetic distance matrix to summarize the genetic diversity into a batch factor. Using the methods previously mentioned, we were able to integrate genetic diversity into the analysis and bring to light the effect of the ionizing radiation dose in the transcriptomic data
Research and development by the french TSO in support of its safety assessment of the CIGEO license application
No full textInternational audienceRound table with French TS, WMO and waste producers
Avis de l’Anses relatif aux « projet de décret relatif aux eaux réutilisées dans les entreprises du secteur alimentaire et portant diverses dispositions relatives à la sécurité sanitaire des eaux destinées à la consommation humaine et projet d’arrêté relatif à l’autorisation de production et d’utilisation d’eau réutilisée en vue de la préparation et de la conservation dans les entreprises alimentaires de toutes denrées et marchandises destinées à l’alimentation humaine »
No full textCitation suggérée : Anses. (2023). Avis de l'Anses relatif aux « projet de décret relatif aux eaux réutilisées dans les entreprises du secteur alimentaire et portant diverses dispositions relatives à la sécurité sanitaire des eaux destinées à la consommation humaine et projet d’arrêté relatif à l’autorisation de production et d’utilisation d’eau réutilisée en vue de la préparation et de la conservation dans les entreprises alimentaires de toutes denrées et marchandises destinéesà l’alimentation humaine » (saisine 2023-SA-0088). Maisons-Alfort : Anses, 63 p.Les ressources en eau subissent des pressions de plus en plus importantes au niveau mondial, dues à diverses causes comme le dérèglement climatique, l’augmentation de la démographie, l’urbanisation et l’industrialisation. Dans la production des aliments, l’eau joue un rôle essentiel, lors de l’irrigation des cultures destinées à l’alimentation humaine et animale, lors la préparation des aliments et lors de leur transformation en industrie. Dans les entreprises agroalimentaires, cette eau peut être utilisée en tant qu’ingrédient de certains aliments transformés, entrer en contact direct (par exemple, lavage des légumes) ou indirect (par exemple, lavage des matériels) avec les denrées alimentaires ou être employée en dehors de la chaîne de production, sans contact avec les denrées (par exemple, dans un pasteurisateur).De l’eau peut également être extraite directement à partir de l’aliment lui-même, lors de certaines étapes de transformation (par exemple, séchage du lait). Ces utilisations et cette production d’eau à partir des aliments génèrent des eaux de qualité variables, qui sont actuellement essentiellement rejetées comme eaux usées vers des stations de traitement des eaux usées (STEU). Dans les secteurs d’activité de l’agroalimentaire nécessitant d’importants volumes d’eau, en particulier pour le lavage des légumes bruts ou celui des locaux et matériels,les entreprises recherchent des solutions durables pour réduire les coûts liés à l’approvisionnement en eaux destinées à la consommation humaine (EDCH), limiter leur impact sur l’environnement et maintenir leur activité en cas de restrictions d’eau imposées par arrêté préfectoral. Ce type de démarche, d’intérêt à la fois écologique et économique, n’était jusqu’à présent pas pris en compte par les dispositions réglementaires en vigueur en France.Néanmoins, le décret n° 2021-807 du 24 juin 2021 pris en application de l'article L. 211-1 du code de l'environnement, relatif à la promotion d'une utilisation efficace, économe et durable de la ressource en eau, permet la réutilisation des eaux usées traitées et l'utilisation des eaux de pluie dans les installations classées pour la protection de l'environnement (ICPE) et les installations, ouvrages, travaux et activités (IOTA) nouveaux et existants. De plus, le plan d’action gouvernemental pour une gestion résiliente et concertée de l’eau publié récemment décline 53 mesures. Parmi celles qui visent à « valoriser les eaux non conventionnelles », une mesure indique que « les freins réglementaires à la valorisation des eaux non conventionnelles seront levés à la fois dans l’industrie agro-alimentaire, dans d’autres secteurs industriels et pour certains usages domestiques, dans le respect de la protection de la santé des populations et des écosystèmes. » (extrait
Evaluation des interactions toxicopathologiques (Nosema ceranae) des rayonnements ionisants chez les abeilles, Apis mellifera
No full textInternational audienceThe radiocontamination of the environment is a major ecological issue. To better anticipate the consequences of nuclear accidents, it is necessary to improve our knowledge of the environmental impacts and risks of irradiation and contamination related to radioactive elements. In the context of my thesis, the honeybee, Apis mellifera, was chosen as a model to study the effects of ionizing radiation (IR). Because very few data exist on this subject, the objective of the research program is to deepen the knowledge of the effects and mechanisms involved in the action of IR on bees.My thesis will be based on two approaches: field and laboratory. The field part is developed by monitoring hives placed on sites around the Fukushima nuclear power plant during 2 years. The laboratory part is brought by exposing bees to external irradiation during experiments conducted in controlled conditions. An estimation of the total dose rates absorbed by the bees will be established. A large part of my thesis focuses on the evaluation of the physiological effects induced by IR on bees, as well as the toxicopathological effects. Effects induced at individual and population levels will also be described. Results obtained in field and laboratory experiments will be compared to investigate whether data observed in laboratory conditions could be extrapolated to predict effects in real conditions.La radiocontamination de l’environnement est un enjeu écologique majeur. Pour mieux anticiper les conséquences des accidents nucléaires, il est nécessaire d’améliorer nos connaissances sur les impacts environnementaux et les risques d’irradiation et de contamination liés aux éléments radioactifs. Dans le cadre de ma thèse, l’abeille domestique, Apis mellifera, a été choisie comme modèle pour étudier les effets des rayonnements ionisants (IR). Parce que très peu de données existent sur ce sujet, l’objectif du programme de recherche est d’approfondir la connaissance des effets et des mécanismes impliqués dans l’action des IR sur les abeilles.Ma thèse s’appuiera sur deux approches : terrain et laboratoire. La partie terrain est développée par le suivi de ruches placées sur des sites autour de la centrale nucléaire de Fukushima pendant 2 ans. La partie laboratoire est apportée en exposant les abeilles à une irradiation externe lors d’expériences menées en conditions contrôlées. Une estimation des débits de dose totaux absorbés par les abeilles sera établie. Une grande partie de ma thèse porte sur l’évaluation des effets physiologiques induits par les IR sur les abeilles, ainsi que les effets toxicopathologiques. Les effets induits aux niveaux individuel et populationnel seront également décrits. Les résultats obtenus lors d'expériences sur le terrain et en laboratoire seront comparés pour déterminer si les données observées en laboratoire peuvent être extrapolées pour prédire les effets dans des conditions réelles
Radial Hydride Precipitation in Fuel Cladding During Back-End Cooling Transient Under Decreasing Pressure
No full textInternational audienceDuring spent fuel assembly transportation or dry cask storage, fillinggas and fission gas release pressurize the fuel rods contained in the cask. Theserods are heated by fuel assembly residual power resulting in internal pressurizationstress increase in the rods. During the subsequent cooling associated to removal ofrods from the transportation cask or during the decrease of residual power after along storage period, the cladding hoop stress is expected to decrease. Concomitantcladding temperature and stress decrease may influence the morphology of precipitatedhydrides in corroded claddings. Radial hydride precipitation has a detrimentalrole on the mechanical resistance of the cladding and is promoted by largehoop stresses during the cooling of the cladding. There is, consequently, a need topredict the radial hydride precipitation in corroded cladding tubes during dry storageor transportation cooling transients. Existing models usually address the radialhydride precipitation conditions under constant stress leading to over-estimatedradial hydride content within the cladding