Frontiers in Nuclear Engineering最新文献

{"title":"Improved localization of radioactivity with a normalized sinc transform","authors":"Ioannis Tsitsimpelis, T. Alton, A. West, C. J. Taylor, F. Livens, B. Lennox, M. Joyce","doi":"10.3389/fnuen.2022.989361","DOIUrl":"https://doi.org/10.3389/fnuen.2022.989361","url":null,"abstract":"A technique for the in-situ localization of radioactivity is described in which the influence of γ-radiation impinging on a high-Z collimator, by which the angular response of a scintillation detector is constrained in order to identify the corresponding angular position of the radiation source, is expressed mathematically by way of a normalized sinc transform. We test this approach by examining the utility of the sinc transform to express the angular responses derived from a slot-collimated cerium bromide detector, across a variety of energy regions. Individual spectra have been acquired as a function of angle to explore how the shape of the response of the collimator-detector arrangement changes for X-rays and γ rays. A 90% improvement in localization is observed when this is defined in terms of the area described by the variance between the known location and that indicated by the response of the collimated system. This approach has the potential to improve source location accuracy and to further optimize autonomous robot exploration routines used to characterize contaminated environments associated with nuclear legacies and radiological emergencies.","PeriodicalId":400400,"journal":{"name":"Frontiers in Nuclear Engineering","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116744526","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":"U(VI), Np(V), Eu(III) sorption on goethite: A wide-ranging multiradionuclide dataset and uncertainty-aware parametrization of surface complexation models","authors":"A. Romanchuk, V. Svitelman, P. D. Blinov, A. Larina, Lurii M. Nevolin, A. V. Egorov, E. Saveleva, S. Kalmykov","doi":"10.3389/fnuen.2022.969171","DOIUrl":"https://doi.org/10.3389/fnuen.2022.969171","url":null,"abstract":"Obtaining reliable thermodynamic sorption data is essential for establishing databases that can be used for the numerical safety evaluations of radioactive waste storage and disposal facilities. For this purpose, new experimental data on the sorption of U(VI), Np(V), and Eu(III) onto synthesized goethite in a wide range of experimental conditions were collected. Thermodynamic surface complexation models based on different approaches were developed and parametrized to fit a large dataset, including experimental data from the current work as well as available literature data. The proposed heuristic optimization procedure allowed identifying and comparing different parametrization variants and their uncertainties for considered models. The developed models pass the test on additional Cd(II) and Zn(II) data, simultaneously providing a reliable description of the sorption process for five cations and could probably be extended using the obtained linear free energy relationship.","PeriodicalId":400400,"journal":{"name":"Frontiers in Nuclear Engineering","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127525713","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":"Grand challenges in nuclear materials new insights into nuclear materials using ion irradiation, CryoEM, and in-situ liquid cell microscopy","authors":"E. Buck","doi":"10.3389/fnuen.2022.975132","DOIUrl":"https://doi.org/10.3389/fnuen.2022.975132","url":null,"abstract":"Any material used in a nuclear reactor facility must go through an extensive review and qualification, involving many tests and analyses. In late 2019, Alloy 617 was added to the American Society of Mechanical Engineers (ASME) code, representing the first hightemperature material cleared for commercial nuclear reactor use in the United States. since the 1990s. Without new materials, the promise of advanced fission and fusion reactor designs will not be realized (Allen et al., 2010). Similarly, the need to improve current designs and reactor components to extend reactor lifetimes may require deeper understanding of the behavior of nuclear materials under extreme conditions (Was et al., 2019). Advanced reactor concepts will require the materials and components to be resistant to 1) higher temperatures than experienced with current light water reactors, 2) corrosion with liquid salts and liquid metals, and 3) high radiation fields (neutron, ion, and gamma/beta radiation fields). Materials that need to be licensed for use in the nuclear fuel cycle from reactor operation to long-term geologic disposal undergo unparalleled scrutiny. How can this process be sped up without jeopardizing future operational safety? Modern computational predictive tools could help to accelerate development and qualification of advanced materials (Devanathan et al., 2010). However, this may not necessarily negate the requirement for extensive long-term testing of material properties to satisfy regulatory requirements. In this article, as well as discussing the role of ion irradiation studies for nuclear materials research, the potential opportunities for in-situ liquid/gas cell electron microscopy (LC-EM) and Cryo-Electron Microscopy (CryoEM) will be discussed. Ion irradiation in the transmission electron microscope (TEM) has been an important method for testing radiation damage in materials for nuclear applications, including nuclear waste forms and nuclear reactor components. Two other microscopy-based techniques, in-situ liquid/gas cell electron microscopy (LC-EM) and Cryo-Electron Microscopy (CryoEM) are currently being used in several areas in materials research, including, catalysis research, battery development, and geochemistry. Nuclear materials, whether in a nuclear reactor or disposed thousands of meters underground in a geologic repository, are subject to internal atomic displacement damage and the interaction of radiolytic species at the material’s interface. Developing the tools to OPEN ACCESS","PeriodicalId":400400,"journal":{"name":"Frontiers in Nuclear Engineering","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131561242","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":"Grand Challenges in Nuclear Engineering","authors":"S. Dudarev","doi":"10.3389/fnuen.2022.945270","DOIUrl":"https://doi.org/10.3389/fnuen.2022.945270","url":null,"abstract":"The 1992 United Nations Rio de Janeiro declaration (United Nations, 1992) states that “Human beings are at the centre of concerns for sustainable development. They are entitled to a healthy and productive life in harmony with nature.” This brief affirmation highlights the implications from the impact of growing human population on the environment (Cartledge, 1995; MacKay, 2009), manifested in the notion of climate emergency (Ripple et al., 2020). Nuclear power offers progressive options to mitigate global warming and other effects of climate change, with the International Energy Agency (IEA) suggesting that the nuclear energy generation currently eliminates between 1.3 and 2.6 giga-tonnes of CO2 emissions from the power sector each year, depending on whether it is assumed that it replaces gasor coal-fired power plants. The IEA’s 2015Technology Roadmap (IEA, 2015) report noted that tomeet the Paris Agreement target of global temperature not rising by more than 2°C, the world nuclear power generation capacity needs to increase to 930 GW in 2050. For comparison, the Smart Energy Europe analysis projected the European nuclear power generation capacity in 2050 to the level of 105 GW (Connolly et al., 2016), against the current levels of 61.3 GW in France, 9 GW in the United Kingdom, raising to 24 GW by 2050 (UK Government, 2022), and 4.3 GW in Germany, down from the 2021 level of 7.4 GW. Comparing these figures and the data for other geographical areas with the projected world total nuclear generation capacity, we observe that many new power plants are expected to be constructed in the countries where nuclear power generation technology and engineering have so far been largely unknown. This expected expansion will involve a broad range of engineering and technological challenges spanning the manufacturing of reactor components, the fabrication and extraction of fuel, the development of efficient coolant and heat transfer technology, the reactor assembly schedules, the establishment of supporting hot cell and waste processing facilities, and the technology for scheduled and unscheduled remote maintenance and operation, enabling the reactor systems to reliably function over long periods of time. All the presently operating commercial nuclear reactors use fissile nuclear fuel, containing isotopes of uranium and other actinide elements. On the other hand, fusion power generation, an area of active development and innovation worldwide, aims to use light fusable chemical elements, for example the deuterium and tritium isotopes of hydrogen (Pearson and Takeda, 2020; Prager and Najmabadi, 2020). Fusion technology presents a range of scientific and engineering challenges that need to be addressed to enable the construction of a fusion power plant (Chapman and Walkden, 2020). These include the development of a reliable and safe tritium and deuterium extraction and handling technology, the integration of structural and functional materials in a power plant desig","PeriodicalId":400400,"journal":{"name":"Frontiers in Nuclear Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131174133","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":"Computational Framework for Radionuclide Migration Assessment in Clay Rocks","authors":"Jaime Garibay-Rodriguez, Chaofan Chen, H. Shao, L. Bilke, O. Kolditz, V. Montoya, R. Lu","doi":"10.3389/fnuen.2022.919541","DOIUrl":"https://doi.org/10.3389/fnuen.2022.919541","url":null,"abstract":"In the context of nuclear waste disposal, a pre-requisite to assure their long term safety is the need for safety assessment studies aided by computational simulations, in particular, radionuclide migration from the waste to the geosphere. It is established that underground repositories for nuclear waste will provide retardation barriers for radionuclides. However, the understanding of the sorption mechanisms of radionuclides onto mineral surfaces (i.e., illite, montmorillonite) is essential for modelling their migration. On the other hand, mechanistic-based radionuclide migration simulations, typically for 1 million years, poses a computational challenge. Surrogate-based simulations can be useful to enable sensitivity/uncertainty analysis that would be prohibitive otherwise. Considering the current challenges in modelling radionuclide migration and the importance of the results and implications of these simulations (i.e., for the public and nuclear waste management agencies), it is necessary to provide appropriate computational tools in a transparent and easy-to-use way. In this work, we aim to provide such tools in a framework that combines the simulation capabilities of OpenGeoSys6 for radionuclide migration and the approachable nature of Project Jupyter (i.e., JupyterLab), which provides a modular web-based environment for development, simulation and data. In this way, we aim to promote the collaborative research of radionuclide migration assessment and, at the same time, to guarantee the availability and reproducibility of the scientific outcome through the OpenGeoSys initiative.","PeriodicalId":400400,"journal":{"name":"Frontiers in Nuclear Engineering","volume":"329 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133748547","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":"Radon Concentrations in Indoor and Outdoor Environments of Atomic Energy Centre Dhaka, Bangladesh, and Concomitant Health Hazards","authors":"S. Pervin, S. Yeasmin, Mayeen Uddin Khandaker, A. Begum","doi":"10.3389/fnuen.2022.901818","DOIUrl":"https://doi.org/10.3389/fnuen.2022.901818","url":null,"abstract":"Realizing the non-negligible health hazards due to radon exposure, the present study was carried out to measure the radon concentrations in indoor and outdoor environments of Atomic Energy Centre Dhaka (AECD), Bangladesh. A portable electrostatic radon-measuring device (RAD7) was used to determine the indoor radon levels in different laboratories of AECD, and a RAD7 detector with a stainless steel soil probe was employed to measure the soil gas radon in the surrounding areas of the AECD campus. The indoor radon concentration in various laboratories was found to vary from 11 ± 7 Bq/m3 to 360 ± 180 Bq/m3 with an average of 63 ± 33 Bq/m3. Overall, the average indoor radon level shows below the action level (300 Bq/m3) recommended by ICRP publication-126 for homes and workplaces. However, the laboratories having poor ventilation show a relatively higher radon level. The average soil gas radon concentration at different depths of 15 cm, 35 cm, and 55 cm was found to be 0.07 ± 0.01 kBq/m3, 2.31 ± 0.31 kBq/m3, and 22.5 ± 1.4 kBq/m3, respectively. The calculated average annual effective dose due to the inhalation of indoor radon in home and workplaces was found to be below the ICRP recommended value of 10 mSv/y. The present results could serve as a reference radon level in the indoor and outdoor environment in Dhaka city, Bangladesh.","PeriodicalId":400400,"journal":{"name":"Frontiers in Nuclear Engineering","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123934464","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 relative humidity, surface area and production route on hydrogen yields from water on the surface of plutonium dioxide","authors":"K. Webb, C. Gregson, J. Holt, Bliss McLuckie, R. Orr, H. Sims, D. Woodhead, J. Hobbs, H. Steele, F. Currell, Luke Jones, S. Pimblott, R. Taylor","doi":"10.3389/fnuen.2023.1127504","DOIUrl":"https://doi.org/10.3389/fnuen.2023.1127504","url":null,"abstract":"Over 60 samples of plutonium dioxide (PuO2) powders of varying provenance have been exposed to humid atmospheres and the hydrogen (H2) generation rates measured by gas chromatography. The effects of relative humidity (RH), specific surface area (SSA), plutonium isotopic composition (absorbed dose), and overlying atmosphere have been investigated for ‘as received’ PuO2 powders from the United Kingdom’s Thorp and Magnox reprocessing plants, high surface area powder produced in the laboratory and Magnox PuO2 that was recalcined at 800, 900 or 950°C. Hydrogen generation was shown to be susceptible to subtle influences with the most consistent results observed at 95% RH. However, it was shown that the measured (net) hydrogen decreases with decreasing RH and with atmosphere in the order: Air > argon > nitrogen. There was no clear effect of SSA, apart from with the highest SSA samples (∼40 m2.g−1) but these powders also have very different morphology, porosity, and carbon content to the rest. The results presented substantially enhance the growing body of literature on the factors that determine hydrogen and gas generation from PuO2 that has significant implications for long term safe storage of plutonium globally.","PeriodicalId":400400,"journal":{"name":"Frontiers in Nuclear Engineering","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128022850","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}