Journal of Nuclear Science and Technology最新文献

{"title":"A multiclass classification model for predicting the thermal conductivity of uranium compounds","authors":"Y. Sun, M. Kumagai, M. Jin, E. Sato, M. Aoki, Y. Ohishi, K. Kurosaki","doi":"10.1080/00223131.2023.2269974","DOIUrl":"https://doi.org/10.1080/00223131.2023.2269974","url":null,"abstract":"ABSTRACTAdvanced nuclear fuels are designed to offer improved performance and accident tol- erance, with an emphasis on achieving higher thermal conductivity. While promising fuel candidates like uranium nitrides, carbides, and silicides have been widely stud- ied, the majority of uranium compounds remain unexplored. To search for potential candidates among these unexplored uranium compounds, we incorporated machine learning to accelerate the material discovery process. In this study, we trained a multiclass classification model to predict a compound’s thermal conductivity based on 133 input features derived from element properties and temperature. The initial training data consists of over 160,000 processed thermal conductivity records from the Starrydata2 database, but a skewed data class distribution led the trained model to underestimate compound’s thermal conductivity. Consequently, we addressed the issue of class imbalance by applying Synthetic Minority Oversampling TEchnique and Random UnderSampling, improving the recall for materials with thermal con- ductivity higher than 15 W/mK from 0.64 to 0.71. Finally, our best model is used to identify 119 potential advanced fuel candidates with high thermal conductivity among 774 stable uranium compounds. Our results underscore the potential of ma- chine learning in the field of nuclear science, accelerating the discovery of advanced nuclear materials.KEYWORDS: Advanced nuclear fuelsMachine learningthermal conductivityDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. Disclosure statementNo potential conflict of interest was reported by the author(s).Data availability statementThe data that support the findings of this study are openly available at https://github.com/AzarashiYifan/classification-uranium-thermal-conductivity.Additional informationFundingThis work was supported by MEXT Innovative Nuclear Research and Development Program Grant Number JPMXD0220354330 and JPMXD0222682541.","PeriodicalId":16526,"journal":{"name":"Journal of Nuclear Science and Technology","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135616877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Creep deformation and rupture behavior of 9Cr-ODS steel cladding tube at high temperatures from 700°C to 1000°C","authors":"Yuya Imagawa, Ryuta Hashidate, Takeshi Miyazawa, Takashi Onizawa, Satoshi Ohtsuka, Yasuhide Yano, Takashi Tanno, Takeji Kaito, Masato Ohnuma, Masatoshi Mitsuhara, Takeshi Toyama","doi":"10.1080/00223131.2023.2269178","DOIUrl":"https://doi.org/10.1080/00223131.2023.2269178","url":null,"abstract":"ABSTRACTThe Japan Atomic Energy Agency has been developing 9Cr-oxide dispersion strengthened (ODS) steel as a fuel cladding material for sodium-cooled fast reactors (SFRs). Previous studies have formulated the creep rupture equation for 650°C–850°C. However, little data have been obtained above 850°C, and no equation has been formulated. This study conducted creep tests to evaluate creep strength at 700°C–1000°C. Two creep test methods, the internal pressure and ring creep tests under development, were used, and the validation of the ring creep test method was conducted. The results showed that 9Cr-ODS steel undergoes almost no strength change due to the matrix’s phase transformation, and a single equation can express a creep rupture strength from 700°C to 1000°C. In validating the ring creep test method, analysis clarified the effect of stress concentration on the specimen. Plastic deformation occurs at high initial stress and may lead to early rupture. The results will be essential for future creep testing and evaluation of neutron-irradiated 9Cr-ODS steel.KEYWORDS: Oxide dispersion strengthened steelfuel cladding tube,creep strengthcreep straininternal creep testring creep testDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgmentsThe authors would like to express their sincere gratitude to Dr. Tomoyuki Uwaba for his valuable guidance on finite element simulation.Additional informationFundingMEXT Innovative Nuclear Research and Development Program Grant Number JPMXD0219214482, Ministry of Education Culture, Sports, Science, and Technology, supported this work.","PeriodicalId":16526,"journal":{"name":"Journal of Nuclear Science and Technology","volume":"162 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135730090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Benchmark simulation code for the thermal-hydraulics design tool of the accelerator-driven system: validation and benchmark simulation of flow behavior around the beam window","authors":"Susumu Yamashita, Nao Kondo, Takanori Sugawara, Hideaki Monji, Hiroyuki Yoshida","doi":"10.1080/00223131.2023.2268676","DOIUrl":"https://doi.org/10.1080/00223131.2023.2268676","url":null,"abstract":"ABSTRACTA detailed computational fluid dynamics code named JAEA Utility Program for Interdisciplinary Thermal-hydraulics Engineering and Research (JUPITER) for the thermal-hydraulics around the beam window (BW) of accelerator-driven system (ADS) was used to confirm the validity of the thermal-hydraulics design tool based on the ANSYS Fluent. The Fluent uses the Reynolds-averaged Navier – Stokes (RANS) model and can quickly calculates the turbulent flow around the BW as a BW design tool. First, the results of JUPITER were compared with the experimental results using a mock-up BW system in water to confirm the validity of JUPITER. This study confirmed that the numerical results are in good agreement with the experimental results. Thus, JUPITER could be used as a benchmark code. A benchmark simulation for the Fluent calculation was also performed using validated JUPITER to demonstrate the applicability of JUPITER as an alternative for experiments. Therefore, the mean values around the BW agreed with each other (e.g. the mean velocity profile for the stream and horizontal directions). Therefore, results confirmed that JUPITER demonstrated a good performance in validating the thermal-hydraulics design tool as a fluid dynamics solver. Moreover, Fluent has sufficient accuracy as a thermal-hydraulics design tool for the ADS.KEYWORDS: Computational fluid dynamics (CFD)thermal-hydraulicsaccelerator-driven system (ADS)beam windowlead-bismuth eutectic flowDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgmentsThis research was conducted using the supercomputer HPE SGI8600 at the Japan Atomic Energy Agency. The authors would like to express their gratitude to Mr. Asari (LIFULL Co., Ltd.) for fruitful discussions about the mock-up experiment.NomenclatureTableDisplay TableFigure 1. Conceptual view of LBE-cooled ADS (left) and its BW (right)Display full sizeFigure 2. Schematic diagram of the experimental apparatusDisplay full sizeFigure 3. System of the experimental analysisDisplay full sizeFigure 4. Definitions of jet part and its axes. (a) Free jet part, (b) Impinging jet part. The dotted line indicates the centerline of the jet.Display full sizeFigure 5. Radial distribution of the velocity for the y-direction in the free jet part. (a) numerical simulation and (b) experimentDisplay full sizeFigure 6. Comparison between the simulation and the experiment in the free jet partDisplay full sizeFigure 7. Centerline velocity distribution in impinging jet partDisplay full sizeFigure 8. Comparison between the simulation and the experiment for nondimensional velocity distribut","PeriodicalId":16526,"journal":{"name":"Journal of Nuclear Science and Technology","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135147212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Irradiated mechanical properties predicted by a machine learning method with the Fourier-transform-based feature extension","authors":"Yingxuan Dong, Junnan Lv, Hong Zuo, Qun Li","doi":"10.1080/00223131.2023.2267044","DOIUrl":"https://doi.org/10.1080/00223131.2023.2267044","url":null,"abstract":"ABSTRACTAfter irradiation, the variation of yield strength in metallic materials is multivariate nonlinear. High-dimensional nonlinear relationships between the irradiated yield strength and its influencing factors, including material properties, doses, irradiation temperatures, and crystal structures, etc. are difficult to explicitly characterize in the absence of a comprehensive database. In this study, we developed a machine learning method with the Fourier-transform-based feature extension, successfully constructing the prediction model of irradiated yield strength by a relatively small and sparse database of irradiated material properties. The analysis suggests that the proposed feature extension method improves the training performances of machine learning with small dataset. And the present model is accurate and feasible for predicting the irradiated yielding behaviors. Furthermore, we attempt the inverse machine learning model to determine material properties and irradiation conditions according to the desired yield strength. Since the parameter combinations commensurate with a fixed strength are diverse, the optimal model is helpful in reversely calculating and optimizing material performances. The data-driven machine learning method, which can detect the implicit correlations among numerous data, exhibits great prospects in investigating irradiated mechanical properties and exploring multiscale links in the nuclear material field. This work holds the promise for optimizing the design of in-pile structural components and can be further extended to other machine learning problems with the small dataset.KEYWORDS: Yield strengthmachine learningirradiationDimensional extension method of feature vectorSupported vector machine for regressionDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgmentsThis work was supported by the Natural Science Foundation of China (12172270), the Fund of Science and Technology on Reactor Fuel and Materials Laboratory (6142A06190111), the Project of Nuclear Power Institute of China (No. K902023-04-FW-HT-20220003), the Youth Science and Technology Innovation Team Project of China National Nuclear Corporation (JT211), the Qin Chuangyuan “Scientists+Engineers” Team Construction Project in Shaanxi Province (2022KXJ-085), and the Innovative scientific Program of CNNC. The computation has made use of the High Performance Computing (HPC) platform of Xi’ an Jiaotong University.Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThe work was supported by the National Natur","PeriodicalId":16526,"journal":{"name":"Journal of Nuclear Science and Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135146308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EXFOR-based simultaneous evaluation for neutron-induced fission cross section of plutonium-242","authors":"Riko Okuyama, Naohiko Otuka, Go Chiba, Osamu Iwamoto","doi":"10.1080/00223131.2023.2267070","DOIUrl":"https://doi.org/10.1080/00223131.2023.2267070","url":null,"abstract":"ABSTRACTThe 242Pu neutron-induced fission cross section was evaluated from 100 keV to 200 MeV. The experimental 242Pu and 235U fission cross sections and their ratios in the EXFOR library were reviewed and analysed by the least-squares method. Additional simultaneous evaluation was performed by including the experimental database of the 233,238U and 239,240,241Pu fission cross sections and their ratios developed for JENDL-5 evaluation. The 242Pu fission cross sec- tions from our evaluation and JENDL-5 evaluation are close to each other below 1 MeV while systematically differ from each other above 10 MeV. The cross section from our evaluation is systematically lower than the JENDL-4.0 cross section in the prompt fission neutron spectrum peak region (∼5% lower around 1 MeV). The newly evaluated 242Pu fission cross section was verified against the cross section measured in the 252Cf spontaneous fission neutron field and criticalities of small-sized LANL fast systems, and demonstrated better performance than the JENDL-4.0 cross section on the same level with the JENDL-5 cross section.KEYWORDS: Plutonium-242fissionsimultaneous evaluationJENDLEXFORDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgementAntonio Jime´nez-Carrascosa and Oscar Cabellos (Universidad Polite´cnica de Madrid) per- formed criticality calculations by KENO to check if our criticality calculations are reasonable. We thank Melissa Denecke (IAEA) for careful reading of the manuscript. RO would like tothank the members of IAEA Nuclear Data Section for their hospitality during her internship. Her internship was financially supported by “Fundamental Nuclear Education Program by Japanese University Network for Global Nuclear Human Resource Development” entrusted to Tokyo Institute of Technology by Ministry of Education, Culture, Sports, Science and Technology (MEXT).Figure 1 242Pu/235U fission cross section ratios below 1 MeV from evaluations along with the experimental ones used in the present evaluationCitation13, Citation48, Citation52, Citation53, Citation56, Citation57.Display full sizeFigure 2 242Pu/235U fission cross section ratios above 1 MeV from evaluations along with the experimental ones used in the present evaluationCitation13, Citation48, Citation52–57.Display full sizeFigure 3 242Pu fission cross sections from evaluations along with the experimen- tal ones used in the present evaluationCitation12, Citation14, Citation15, Citation50, Citation51. Three datasets excluded from the present evaluationCitation11, Citation16, Citation27 are also plotted by grey symbols.Display full sizeF","PeriodicalId":16526,"journal":{"name":"Journal of Nuclear Science and Technology","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135346739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of extremely high-temperature X-ray absorption fine structure measurement method for oxide samples","authors":"Keisuke Niino, Yuji Arita, Kenji Konashi, Hiromichi Watanabe, Tsuyoshi Yaita, Hajime Tanida, Tohru Kobayashi, Kyoichi Morimoto, Masashi Watanabe, Yusuke Miura","doi":"10.1080/00223131.2023.2267560","DOIUrl":"https://doi.org/10.1080/00223131.2023.2267560","url":null,"abstract":"Click to increase image sizeClick to decrease image size AcknowledgementsThis research was supported by the Japan MEXT National Problem-Making R&D Promotion Project “Acceleration of Nuclear Fuel Development Research Incorporating Artificial Intelligence (AI) Technology” for the Nuclear Energy System Research and Development Project. The synchrotron radiation experiments were performed at BL22XU in SPring-8 with the approval of the Japan Atomic Energy Agency (Proposals No. 2022A3744, 2022B3714, and 2023A3714).Figure 1. Phase diagram of ZrO2–Y2O3 system [Citation7].Display full size Figure 2. Equipment for high-temperature measurement.(a). Photograph of heating chamber. (b). Schematic diagram of heating system.Display full size Figure 3. Newly conceived sample holder with slit for high-temperature X-ray absorption fine structure measurement.Display full size Figure 4. Current density distribution (element vector) near the slit of a heater by finite-element analysis (at current = 120 A).Display full size Figure 5. Temperature distribution using finite-element analysis of a slit heater (at current = 120 A)Display full size Figure 6. Temperature relative to current value estimated using finite-element method analysis.Display full size Figure 7. High-temperature X-ray absorption fine structure spectra obtained from room temperature (RT) to 3427 K.Display full size Figure 8. X-ray absorption fine structure spectra of 10A (solid phase) and 180A (liquid phase) and absorption change α(×10).Display full size Figure 9. Plotting Δα versus current for phase transformation and melting analysis. (Error bars on the X-axis are control variations in current values, which are 0.1A. Because they are extremely small, the error bars look like crosses. Error bars on the Y-axis are evaluated based on the statistical variation of the measured data.)Display full size Figure 10. Scanning electron microscopy images of yttria-stabilized zirconia (YSZ) sample before and after measurement. (a)Sample holder filled with YSZ powder (before XAFS measurement). (b)After XAFS measurement.Display full size Figure 11 Comparison of temperature calibration results and finite-element method analysis results.Display full sizeAdditional informationFundingThe work was supported by the The Japan MEXT National Problem-Making R&D Promotion Project ”Acceleration of Nuclear Fuel Development Research Incorporating Artificial Intelligence (AI) Technology” for the Nuclear Energy System Research and Development Project. .","PeriodicalId":16526,"journal":{"name":"Journal of Nuclear Science and Technology","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135346911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Basic study on tritium monitor using plastic scintillator for treated water discharge at Fukushima Daiichi Nuclear Power plant","authors":"Yukihisa Sanada, Tomohisa Abe, Miyuki Sasaki, Marina Kanno, Tsutomu Yamada, Takamasa Nakasone, Nobuyuki Miyazaki, Keisuke Oshikiri, Hiroshi Watabe","doi":"10.1080/00223131.2023.2258880","DOIUrl":"https://doi.org/10.1080/00223131.2023.2258880","url":null,"abstract":"In response to the Fukushima Daiichi Nuclear Power Station (FDNPS) accident, the treated water from which the primary radioactive substances were removed contained tritium, and the Japanese government discussed how to treat this water. As the storage capacity of the treated water reached its limit, the Japanese government decided on a method to discharge the treated water into the sea in 2023. Herein, a basic study was conducted to develop a tritiated monitor to directly measure tritium in wastewater for preparing the release of tritiated water from the FDNPS. Two plastic scintillators with different shapes (sheet and pellet types) were compared as detectors. The pellet-type detector was found to be more sensitive to tritiated water than the sheet-type, with an efficiency of 2.95 × 10−5 cps Bq−1 L in the test configuration. In the future, optimizing the design for background reduction should achieve a minimum detectable radioactivity of 1,500 Bq L−1, the emission standard set by nuclear power plant operators. Through this study, we could obtain basic data for developing such a practical tritiated monitor.","PeriodicalId":16526,"journal":{"name":"Journal of Nuclear Science and Technology","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135925658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-dimensional elemental mapping of simulated fuel debris using laser-induced breakdown spectroscopy","authors":"Munkhbat Batsaikhan, Katsuaki Akaoka, Morihisa Saeki, Takahiro Karino, Hironori Ohba, Ikuo Wakaida","doi":"10.1080/00223131.2023.2255186","DOIUrl":"https://doi.org/10.1080/00223131.2023.2255186","url":null,"abstract":"ABSTRACTIn this experimental study, two-dimensional elemental mapping of simulated fuel debris was conducted by laser-induced breakdown spectroscopy (LIBS). Since the real fuel debris was unavailable as a sample, simulated fuel debris was prepared from predicted materials including compounds and metals. An Nd:YAG laser at the second harmonic was used to generate plasma on the sample surface, and the optical emission from plasma was detected using an echelle spectrometer in the visible wavelength range from 435 to 650 nm. Due to the size and complexity of the collected dataset, the conventional data analysis method was ineffective; consequently, there arose a need to design a new data analysis method for study purposes. Therefore, in the present study, a method that is based on label-free chemometric methods, such as Principal Component Analysis and Multivariate Curve Resolution-Alternative Least Square methods, were implemented to obtain the spatial and spectral information regarding each constituent within the simulated sample. The study results demonstrated that the integration of LIBS and chemometric methods is a highly effective tool to obtain qualitative information regarding samples (e.g. fuel debris) with little or no prior knowledge.KEYWORDS: Laser-induced breakdown spectroscopychemometricsFukushima Daiichi nuclear power stationnuclear fuel debris Disclosure statementNo potential conflict of interest was reported by the author(s).","PeriodicalId":16526,"journal":{"name":"Journal of Nuclear Science and Technology","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136136885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of nuclear de-excitation model EBITEM Ver.2","authors":"T. Ogawa, S. Hashimoto, T. Sato","doi":"10.1080/00223131.2023.2261932","DOIUrl":"https://doi.org/10.1080/00223131.2023.2261932","url":null,"abstract":"ABSTRACTThe gamma de-excitation model of the general-purpose radiation transport code Particle and Heavy Ion Transport code System, called the Evaluated Nuclear Structure Data File (ENSDF)-Based Isomeric Transition and isomEr production Model (EBITEM) has been upgraded with a focus on precise neutron-capture reaction simulation. The first de-excitation subsequent to neutron capture of numerous nuclei, which was formerly simulated by a model based on the single particle model, is calculated using the Evaluated Gamma Activation File. The database used for further de-excitation, ENSDF, retrieved in 2013, was replaced with Reference Input Parameter Library 3 to consider internal conversion. The internal conversion process was interfaced with the atomic de-excitation model to assess the emission of Auger electrons and fluorescent X-rays. The spectra of gamma-rays from neutron-capture reactions calculated by the upgraded EBITEM correlate better with the evaluated cross-section data than those of the previous version.KEYWORDS: Nuclear de-excitationprompt-gamma raysinternal conversion electronsfluorescent X-raysAuger electronsneutron captureEGAFRIPL-3EBITEMPHITS AcknowledgmentsT.O. would like to appreciate Dr. Camilo Cordero Ramirez and Dr. Cdric Jouanne of CEA (French Alternative Energies and Atomic Energy Commission) for useful discussions on the gamma de-excitation simulation algorithms and relevant databases. Also, T.O. would like to thank Dr. Koji Niita of RIST for his useful suggestions on the model development.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was partly supported by JSPS KAKENHI grant number [18K14159].","PeriodicalId":16526,"journal":{"name":"Journal of Nuclear Science and Technology","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136154064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isoplethal study of phase formation and morphology in uranium-304L steel via scanning electron microscopy","authors":"Andrew Miskowiec, Zachary E. Brubaker, Jenn Neu, J. L. Niedziela, Liam Collins, Alexander Braatz","doi":"10.1080/00223131.2023.2252823","DOIUrl":"https://doi.org/10.1080/00223131.2023.2252823","url":null,"abstract":"ABSTRACTUnderstanding the formation of uranium alloys with steel is important to advance nuclear technologies involving U metal fuels and machining U metal, and for nuclear forensics applications. No known phase diagram for the quaternary U-(M = Fe, Ni, Cr) system exists. We synthesize samples of U-304 L steel (nominal composition 70.1:18.3:10.4 at% Fe:Cr:Ni) across the U composition range 4.45—63.35 at%U by arc melting under inert conditions. Using the binary UFe phase diagram as a reference, we identify four U-steel alloy phases. We find the known U-Fe analogue phases UM2 and U6M, and two low-U composition phases with nominal compositions UM10 and U2M7. We apply a correlation length analysis to backscatter scanning electron microscopy images of sectioned and polished cross sections to quantify the domain formation length scale. We demonstrate that these depend heavily on the initial composition and range from 30 nm to 1.5 µm. This result, in particular, could be applicable to theoretical predictions of transport properties. Furthering our understanding of U alloy phase formation with important structural elements such as steel primaries is foundational in developing future nuclear technology.Footnote1KEYWORDS: Uraniumsteelalloyselectron microscopyphase morphology Disclosure statementNo potential conflict of interest was reported by the author(s).Notes1. This manuscript has been authored by UT-Battelle LLC under Contract No. DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).2. Fs, or “fissium”, was a combination of noble metal fission products.Additional informationFundingThe work was supported by the National Nuclear Security Administration.","PeriodicalId":16526,"journal":{"name":"Journal of Nuclear Science and Technology","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135060885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}