EPJ Nuclear Sciences & Technologies最新文献

{"title":"Analysis for the ARIANE BM1 and BM3 samples: nuclide inventory and decay heat","authors":"D. Rochman, A. Vasiliev, H. Ferroukhi, M. Hursin","doi":"10.1051/epjn/2021017","DOIUrl":"https://doi.org/10.1051/epjn/2021017","url":null,"abstract":"The Mixed Oxide samples (MOX) ARIANE Post Irradiation Examination samples BM1 and BM3 have been analyzed in this work, based on various two- and three-dimensional models. Calculated and measured nuclide inventories are compared based on CASMO5, SIMULATE and SNF simulations, and calculated values for the decay heat of the assembly containing the samples are also provided. For uncertainty propagation, the covariance information from three different nuclear data libraries are used. Uncertainties from manufacturing tolerances and operating conditions are also considered. The results from these two samples are compared with the ones from two UO2 samples, namely GU1 and GU3, also from the ARIANE program, applying the same calculation scheme and uncertainty assumptions. It is shown that a two-dimensional assembly model provides better agreement with the measurements than a two-dimensional single pin model, and that the full core three-dimensional model provides similar results compared to the assembly model, although no 148Nd normalization is applied for the full core model. For the MOX assembly decay heat, as expected, heavy actinides have a higher contribution compared to the cases with the UO2 samples; additionally, decay heat uncertainties are moderately smaller in the case of the MOX assembly.","PeriodicalId":44454,"journal":{"name":"EPJ Nuclear Sciences & Technologies","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57826933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nuclear data assimilation, scientific basis and current status","authors":"E. Ivanov, Cyrille De Saint-Jean, V. Sobes","doi":"10.1051/EPJN/2021008","DOIUrl":"https://doi.org/10.1051/EPJN/2021008","url":null,"abstract":"The use of Data Assimilation methodologies, known also as a data adjustment, liaises the results of theoretical and experimental studies improving an accuracy of simulation models and giving a confidence to designers and regulation bodies. From the mathematical point of view, it approaches an optimized fit to experimental data revealing unknown causes by known consequences that would be crucial for data calibration and validation. Data assimilation adds value in a ND evaluation process, adjusting nuclear data to particular application providing so-called optimized design-oriented library, calibrating nuclear data involving IEs since all theories and differential experiments provide the only relative values, and providing an evidence-based background for validation of Nuclear data libraries substantiating the UQ process. Similarly, it valorizes experimental data and the experiments, as such involving them in a scientific turnover extracting essential information inherently contained in legacy and newly set up experiments, and prioritizing dedicated basic experimental programs. Given that a number of popular algorithms, including deterministic like Generalized Linear Least Square methodology and stochastic ones like Backward and Hierarchic or Total Monte-Carlo, Hierarchic Monte-Carlo, etc., being different in terms of particular numerical formalism are, though, commonly grounded on the Bayesian theoretical basis. They demonstrated sufficient maturity, providing optimized design-oriented data libraries or evidence-based backgrounds for a science-driven validation of general-purpose libraries in a wide range of practical applications.","PeriodicalId":44454,"journal":{"name":"EPJ Nuclear Sciences & Technologies","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57826772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pu multi-recycling scenarios towards a PWR fleet for a stabilization of spent fuel inventories in France","authors":"F. Courtin, Camille Laguerre, Philippe Miranda, C. Chabert, G. Martin","doi":"10.1051/epjn/2021022","DOIUrl":"https://doi.org/10.1051/epjn/2021022","url":null,"abstract":"Nuclear scenario studies are performed to explore the impact of possible evolutions of nuclear fleets. The nuclear fuel cycle simulation tool COSI, developed by CEA, is used to model these dynamic scenarios and to evaluate them with respect to uranium and plutonium management, fuel reprocessing and waste production. In recent years, scenarios have focused on transitions from the current nuclear French fleet to a deployment of SFR. However, the French Multi-annual Energy Planning has recently postponed the deployment of this technology to the second half of the 21st century. Alternative solutions of plutonium management in PWR are investigated to stabilize total inventories of spent nuclear fuels. The MIX concept is based on homogeneous fuel assemblies where fuel rods are composed of plutonium blended with enriched uranium. In this study, a transition from the current French fleet to an EPR™ fleet is simulated. Two power capacities of the future EPR™ fleet are considered. A progressive deployment of fuel multi-recycling in the EPR™ fleet is implemented to enable stabilization of all spent fuels and plutonium inventories. Natural uranium consumption is also minimized thanks to ERU fuel batches in EPR™. Results are compared with plutonium and uranium mono-recycling in a PWR fleet.","PeriodicalId":44454,"journal":{"name":"EPJ Nuclear Sciences & Technologies","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57826987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of the initial granular structure of clay sealing materials on their swelling properties: experiments and DEM simulations","authors":"B. Dardé, A. Tang, J. Roux, P. Dangla, Jean-Michel Pereira, J. Talandier, M. Vu","doi":"10.1051/epjn/2019059","DOIUrl":"https://doi.org/10.1051/epjn/2019059","url":null,"abstract":"Pellet-based expansive clay materials are considered as a sealing material for closing the galleries in radioactive waste disposal concepts. In repository conditions, the granular mixture progressively homogenises upon hydration by the host rock pore water. The present study focuses on the material behaviour before homogenisation. A grain-scale experimental characterisation is first performed in the laboratory. A model describing the hydromechanical behaviour of a pellet is proposed based on the experimental results. Then, suction-controlled swelling pressure tests are performed in the laboratory. Using Discrete Element Method (DEM) and the model proposed for a single pellet, the tests are successfully simulated. It is highlighted that (i) the swelling pressure evolves in two phases in the investigated suction range, controlled by the granular structure of the mixture; (ii) wall effects at the laboratory scale affects the material response; (iii) measurement variability associated to the sensor diameter is non-negligible; (iv) DEM is a valuable tool able to provide insight into the material behaviour.","PeriodicalId":44454,"journal":{"name":"EPJ Nuclear Sciences & Technologies","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjn/2019059","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47155564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metrology applications to D&D issues: issues at stake for INSIDER European project","authors":"D. Roudil, M. Crozet, S. Picart, B. Russell, M. Herranz, S. Boden, P. Peerani, L. Aldave de Las Heras","doi":"10.1051/epjn/2019052","DOIUrl":"https://doi.org/10.1051/epjn/2019052","url":null,"abstract":"Nuclear metrology is an essential aspect to consider for further improvements of the initial characterization of sites under decommissioning. The H2020 Euratom project INSIDER in June 2017 aims at improving the management of contaminated materials arising from decommissioning and dismantling (D&D) operations by proposing an integrated methodology for radiological characterization. This methodology is based on advanced statistical processing and modelling, coupled with adapted or innovative measurement methods. A metrological approach supports the qualification of this integrated methodology with a concrete application to real projects representative of the use cases identified in the project. Assessment of the outcomes will be used for providing recommendations and guidance resulting in pre-standardization texts.","PeriodicalId":44454,"journal":{"name":"EPJ Nuclear Sciences & Technologies","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjn/2019052","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43621415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A minimal predictive model for better formulations of solvent phases with low viscosity","authors":"Maximilian Pleines, M. Hahn, J. Duhamet, T. Zemb","doi":"10.1051/epjn/2019055","DOIUrl":"https://doi.org/10.1051/epjn/2019055","url":null,"abstract":"The viscosity increase of the organic phase when liquid–liquid extraction processes are intensified causes difficulties for hydrometallurgical processes on industrial scale. In this work, we have analyzed this problem for the example of N,N-dialkylamides in the presence of uranyl nitrate experimentally. Furthermore, we present a minimal model at nanoscale that allows rationalizing the experimental phenomena by connecting the molecular, mesoscopic and macroscopic scale and that allows predicting qualitative trends in viscosity. This model opens broad possibilities in optimizing constraints and is a further step towards knowledge-based formulation of extracting microemulsions formed by microstructures with low connectivity, even at high load with heavy metals.","PeriodicalId":44454,"journal":{"name":"EPJ Nuclear Sciences & Technologies","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjn/2019055","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42813201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydraulic and statistical study of metastable phenomena in PWR rod bundles","authors":"F. Muller","doi":"10.1051/epjn/2019057","DOIUrl":"https://doi.org/10.1051/epjn/2019057","url":null,"abstract":"The analysis of fuel rod bundle flows constitutes a key element of Pressurized-Water Reactors (PWR) safety studies. The present work aims at improving our understanding of nefarious reorganisation phenomena observed by numerous studies in the flow large-scale structures. 3D simulations allowed identifying two distinct reorganisations consisting in a sign change for either a transverse velocity in rod-to-rod gaps or for a subchannel vortex. A Taylor “frozen turbulence” hypothesis was adopted to model the evolution of large-scale 3D structures as transported-2D. A statistical method was applied to the 2D field to determine its thermodynamically stable states through an optimization problem. Similarities were obtained between the PWR coherent structures and the stable states in a simplified 2D geometry. Further, 2D simulations allowed identifying two possible flow bifurcations, each related to one of the reorganisations observed in 3D simulations, laying the foundations for a physical explanation of this phenomenon.","PeriodicalId":44454,"journal":{"name":"EPJ Nuclear Sciences & Technologies","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjn/2019057","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48601590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"INSIDER UC2: the BR3 biological shield preliminary results and future work","authors":"W. Broeckx, B. Rogiers, N. Mangelschots, R. Vandyck, Greet Verstrepen, S. Boden","doi":"10.1051/epjn/2019054","DOIUrl":"https://doi.org/10.1051/epjn/2019054","url":null,"abstract":"Aiming at economical optimization, the characterisation of the biological shield of the Belgian Reactor 3 is one of the three use cases intended to validate the integrated characterization methodology developed within the INSIDER project. Pre-existing data were used to define the sampling design strategy. The additional sampling and analysis program consisted of total gamma measurements at the inner surface of the biological shield (secondary data) and gamma spectrometry measurements on drill core samples (primary data). The newly acquired data is supplemented with the historical available data. The full data set currently consists of a total of 283 secondary and 379 primary data points. Preliminary calculations already provide a clear-cut representation of the three different end-stage classes: unconditional clearance, conditional clearance and radioactive waste. On the short term, the current model will be further refined and completed with proper risk evaluation. On the longer term, we envisage a global uncertainty calculation and sensitivity analysis of the entire process.","PeriodicalId":44454,"journal":{"name":"EPJ Nuclear Sciences & Technologies","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjn/2019054","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48415369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"JRC in Euratom Research and Training Programme − 2014–2020","authors":"S. Abousahl, A. Bucalossi, Victor Esteban Gran, Manuel Martin Ramos","doi":"10.1051/epjn/2019036","DOIUrl":"https://doi.org/10.1051/epjn/2019036","url":null,"abstract":"The Euratom Research and Training Programme 2014–2018 and its extension 2019–2020 (the Euratom Programme) is implemented through direct actions in fission − i.e. research performed by the Commission's Joint Research Centre (JRC), and through indirect actions in fission– i.e. via competitive calls for proposals, and in fusion − i.e. through a comprehensive named-beneficiary co-fund action managed by the Commission's Directorate-General for Research & Innovation (RTD). The general objective of the Programme is “to pursue nuclear research and training activities with an emphasis on the continuous improvement of nuclear safety, security and radiation protection, in particular to potentially contribute to the long-term decarbonisation of the energy system in a safe, efficient and secure way.” The Programme is an integral part of Horizon 2020, the EU Framework Programme for Research and Innovation. The direct actions implemented by the JRC constitute an important part of the Euratom Programme and pursue specific objectives covering: nuclear safety, radioactive waste management, decommissioning, emergency preparedness; nuclear security, safeguards and non-proliferation; standardisation; knowledge management; education and training; and support to the policy of the Union on these fields. The JRC multi-annual work programme for nuclear activities fully reflects the aforementioned objectives. It is structured in about 20 projects, and allocates 48% of its resources to nuclear safety, waste management, decommissioning and emergency preparedness, 33% to nuclear security, safeguards and non-proliferation, 12% to reference standards, nuclear science and non-energy applications and 7% to education, training and knowledge management. To ensure that direct actions are in line with and complement the research and training needs of Member States, JRC is continuously interacting with the main research and scientific institutions in the EU, and actively participating in several technological platforms and associations. JRC also participates as part of the consortia in indirect actions, which allows JRC scientist to engage in top level scientific research, and yields maintaining and further developing JRC's scientific excellence. At the same time, the members of the consortia can have access to unique research infrastructure. The participation of JRC in indirect actions can be improved by exploiting synergies inside the Euratom Programme, and also with the future Horizon Europe Framework Programme. In preparation of the next Euratom Programme 2021–2025, two pilot projects on knowledge management and on open access to JRC research infrastructure will explore and test this improved involvement of JRC in indirect actions. The paper highlights some of the achievements of recent JRC direct actions with a focus on the interaction with EU MS research organisations, as well as some of the most important elements of the Commission Proposal for the next (2021–2025) Euratom Prog","PeriodicalId":44454,"journal":{"name":"EPJ Nuclear Sciences & Technologies","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjn/2019036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41803412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A nuclear owner/operator perspective on ways and means for joint programming on predisposal activities","authors":"M. Pieraccini, Sylvain Granger","doi":"10.1051/epjn/2019039","DOIUrl":"https://doi.org/10.1051/epjn/2019039","url":null,"abstract":"Nuclear decommissioning is a worldwide competitive market. It is also the main source of radioactive waste from the nuclear energy field. In order to reduce the waste volume it is necessary to sort the actual radioactive waste to be disposed of and to separate them from other materials that could be recycled. Since 2015, Electricité de France (EDF) has gathered the waste management and dismantling (WM&D) projects, the related competences and human resources in the WM&D field, in a dedicated directorate (DP2D) and a company group called Cyclife (including waste treatment facilities). Taking into account the experience gained by carrying out its own WM&D projects as well as contributing to international cooperation, EDF considers that integrating collaborative research and development (R&D) on pre-disposal and waste management could be carried out following four main objectives: (1) alignment of the application of regulatory frameworks through appropriate definition of criteria and rules for radioactive waste to enable sensible worldwide comparison of technics; (2) improvement of technical and organisational aspects of nuclear reactors decommissioning using a demonstrator facility to be in operation, at first for graphite reactors, by 2022; (3) development of new techniques to decontaminate/homogenize metallic materials through a dedicated recycling route. These technics will be implemented in a new treatment facility foreseen to be available by 2030; and (4) increased training of decommissioning operators with the help of new technologies. All these improvements are aiming, beyond technical and experimental aspects, at reducing environmental impacts of nuclear activities as well as preserving the radioactive disposal volumes, as they are considered by EDF as rare resources.","PeriodicalId":44454,"journal":{"name":"EPJ Nuclear Sciences & Technologies","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjn/2019039","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48546833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}