Pub Date : 2024-08-18DOI: 10.1016/j.net.2024.08.031
M.H.A. Mhareb, M.I. Sayyed, Rahman I. Mahdi, Kawa M. Kaky, M. Kh Hamad, Abed Jawad Kadhim
In this investigation, we reported three glass samples of Nd (III) ions doped boro-tellurite-germanite glasses. The chemical composition of (35-x) BO–20TeO-10GeO-35MgO-xNdO where x = 2.5, 5, and 7.5, all in mol%, was used to synthesize an optical glass. XRD, FTIR, and optical absorption were utilized to evaluate the structural and optical properties of Nd2.5, Nd5.0, and Nd7.5. X-ray diffraction was measured in the spectra range of 10–80°. Additionally, spectra of FT-IR in the wavenumber range of 400–4000 cm were reported to investigate all structural groups. Several absorption peaks related to the transitions from ground level I to the other excited state were investigated. Various mechanical, optical, and physical properties were calculated theoretically and analyzed to determine the role of the rare earth ions (Nd). The optical electronegativity (χ) and optical basicity (Λ) results showed a reduction in the strength of the bond and formed an ionic bond in the glass structure due to adding NdO. These results align with the reduction in the elastic modulus results by adding NdO instead of BO. Radiation shielding parameters like HVL, TVL, MFP, and Z were thoroughly reported for all Nd2.5, Nd5.0, and Nd7.5, which showed slight improvement when NdO was added instead of BO.
在这项研究中，我们报告了三种掺杂钕 (III) 离子的硼碲锗石玻璃样品。我们采用 (35-x) BO-20TeO-10GeO-35MgO-xNdO 的化学成分合成了一种光学玻璃，其中 x = 2.5、5 和 7.5，均为 mol%。利用 X 射线衍射、傅立叶变换红外光谱和光学吸收来评估 Nd2.5、Nd5.0 和 Nd7.5 的结构和光学特性。X 射线衍射的光谱范围为 10-80°。此外，还报告了波长范围为 400-4000 厘米的傅立叶变换红外光谱，以研究所有结构基团。研究了与从基态 I 到其他激发态跃迁有关的几个吸收峰。对各种机械、光学和物理特性进行了理论计算和分析，以确定稀土离子（钕）的作用。光学电负性（χ）和光学碱性（Λ）结果表明，加入氧化钕后，玻璃结构中的键强度降低，形成了离子键。这些结果与添加氧化钕而不是氧化银后弹性模量降低的结果一致。对所有 Nd2.5、Nd5.0 和 Nd7.5 的辐射屏蔽参数（如 HVL、TVL、MFP 和 Z）进行了详细报告，结果表明，添加 NdO 而不是 BO 后，辐射屏蔽参数略有改善。
{"title":"Role of Nd (III) ions on B2O3–TeO2-GeO2-MgO glass composition for optical and ionizing protection application","authors":"M.H.A. Mhareb, M.I. Sayyed, Rahman I. Mahdi, Kawa M. Kaky, M. Kh Hamad, Abed Jawad Kadhim","doi":"10.1016/j.net.2024.08.031","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.031","url":null,"abstract":"In this investigation, we reported three glass samples of Nd (III) ions doped boro-tellurite-germanite glasses. The chemical composition of (35-x) BO–20TeO-10GeO-35MgO-xNdO where x = 2.5, 5, and 7.5, all in mol%, was used to synthesize an optical glass. XRD, FTIR, and optical absorption were utilized to evaluate the structural and optical properties of Nd2.5, Nd5.0, and Nd7.5. X-ray diffraction was measured in the spectra range of 10–80°. Additionally, spectra of FT-IR in the wavenumber range of 400–4000 cm were reported to investigate all structural groups. Several absorption peaks related to the transitions from ground level I to the other excited state were investigated. Various mechanical, optical, and physical properties were calculated theoretically and analyzed to determine the role of the rare earth ions (Nd). The optical electronegativity (χ) and optical basicity (Λ) results showed a reduction in the strength of the bond and formed an ionic bond in the glass structure due to adding NdO. These results align with the reduction in the elastic modulus results by adding NdO instead of BO. Radiation shielding parameters like HVL, TVL, MFP, and Z were thoroughly reported for all Nd2.5, Nd5.0, and Nd7.5, which showed slight improvement when NdO was added instead of BO.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-18DOI: 10.1016/j.net.2024.08.035
Marwa A. Shewita, Ebrahiem Esmail Ebrahiem, C. Allison, Moustapha Salem Mansour, Ayah E. Elshahat, Mahmoud M. Taha
The current work investigates a computational model to study the thermal and hydraulic air behavior during the natural circulation at air ingression and accidents. This is done with the RHYS coupling ASYST VER 4 package. The test facility considered for the present study is a dual vertical channel facility comprised of two parallel channels connected to the upper and lower plenum. The flow fields in the heated and cooled channels were comprehensively characterized by analyzing axial temperature and velocity distributions using varied uniform iso-flux (100–1400 W/m) and different outer surface temperatures (278, 288, 298, and 308 K). Temperature and velocity reversal recorded after maximal spots due to natural convection. The temperature rise from 278 to 308 K gave an average of 25.51 and 25.19° increase in air and inner wall temperatures, respectively, while air velocity increases at high cooling intensity (278 K) within the heated channel, in the cooled channel, low cooling intensity (308 K) resulted in higher velocity. The convective heat transfer is represented in terms of heat transfer coefficients, which are used to compute the Nusselt number. Additionally, the ASYST model was validated with data from literature sources, indicating strong agreement.
目前的工作研究了一个计算模型，以研究空气进入和事故发生时自然循环过程中的热和水力空气行为。该模型由 RHYS 耦合 ASYST VER 4 软件包完成。本研究考虑的试验设备是双垂直通道设备，由两个平行通道组成，分别连接到上下风箱。通过使用不同的均匀等流量（100-1400 W/m）和不同的外表面温度（278、288、298 和 308 K）分析轴向温度和速度分布，对加热和冷却通道中的流场进行了综合表征。由于自然对流，在最大光斑之后记录到温度和速度反转。温度从 278 K 升至 308 K 时，空气和内壁温度分别平均上升了 25.51 和 25.19°，而在加热通道中，冷却强度高（278 K）时空气流速增加，在冷却通道中，冷却强度低（308 K）时流速增加。对流传热用传热系数表示，用于计算努塞尔特数。此外，ASYST 模型还与文献来源的数据进行了验证，结果表明两者非常吻合。
{"title":"Investigation of computational model for the natural circulation at dual channel facility","authors":"Marwa A. Shewita, Ebrahiem Esmail Ebrahiem, C. Allison, Moustapha Salem Mansour, Ayah E. Elshahat, Mahmoud M. Taha","doi":"10.1016/j.net.2024.08.035","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.035","url":null,"abstract":"The current work investigates a computational model to study the thermal and hydraulic air behavior during the natural circulation at air ingression and accidents. This is done with the RHYS coupling ASYST VER 4 package. The test facility considered for the present study is a dual vertical channel facility comprised of two parallel channels connected to the upper and lower plenum. The flow fields in the heated and cooled channels were comprehensively characterized by analyzing axial temperature and velocity distributions using varied uniform iso-flux (100–1400 W/m) and different outer surface temperatures (278, 288, 298, and 308 K). Temperature and velocity reversal recorded after maximal spots due to natural convection. The temperature rise from 278 to 308 K gave an average of 25.51 and 25.19° increase in air and inner wall temperatures, respectively, while air velocity increases at high cooling intensity (278 K) within the heated channel, in the cooled channel, low cooling intensity (308 K) resulted in higher velocity. The convective heat transfer is represented in terms of heat transfer coefficients, which are used to compute the Nusselt number. Additionally, the ASYST model was validated with data from literature sources, indicating strong agreement.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-17DOI: 10.1016/j.net.2024.08.032
Tao Wu, Jie Wang, Qiuyu Sun, Yifan Yang, Qingyu Si, Chenyu Liang, Guoming Liu, Aijun Mi, Sheng Wang
Tungsten has been widely used for gamma-ray and X-ray radiation shielding, which is one of the main elements of shielding materials. Compared with traditional lead-containing shielding materials, tungsten-containing shielding materials have several advantages, such as good chemical stability, a high melting point and relative environmental friendliness. Considering the recycling of resources, the optimization of pyrolysis temperature and pyrolysis duration of tungsten-filled Vinyl-Methyl-Silicone-based flexible shielding materials needs to be studied. In this paper, these tungsten-filled Vinyl-Methyl-Silicone-based flexible shielding materials were initially recycled using pyrolysis. Subsequently, the crystal structures, surface chemical states and the tungsten concentration after pyrolysis in an argon atmosphere were characterized. In order to increase the tungsten recycling rate, the pyrolyzed samples were further recycled using the ultrasonic cleaning method. Furthermore, the influence of ultrasonic cleaning on tungsten recycling rate and surface morphologies was characterized and analyzed. It is found that the tungsten recycling rate of tungsten-filled Vinyl-Methyl-Silicone based flexible gamma/X-ray shielding material was around 69.9 wt%-81.6 wt% by using the pyrolysis method, while the recycling rate of tungsten can exceed 90.0 wt% by ultrasonic cleaning after pyrolysis.
钨已被广泛用于伽马射线和 X 射线辐射屏蔽，是屏蔽材料的主要元素之一。与传统的含铅屏蔽材料相比，含钨屏蔽材料具有化学稳定性好、熔点高、相对环保等优点。考虑到资源的循环利用，需要对填充钨的乙烯基-甲基-硅基柔性屏蔽材料的热解温度和热解持续时间进行优化研究。本文利用热解法对这些钨填充乙烯基-甲基-硅基柔性屏蔽材料进行了初步回收。随后，在氩气环境中对热解后的晶体结构、表面化学状态和钨浓度进行了表征。为了提高钨的回收率，热解后的样品使用超声波清洗法进一步回收。此外，还表征和分析了超声波清洗对钨回收率和表面形貌的影响。研究发现，使用热解方法，钨填充的乙烯基-甲基-硅基柔性伽马/X 射线屏蔽材料的钨回收率约为 69.9%-81.6 wt%，而热解后通过超声波清洗，钨的回收率可超过 90.0 wt%。
{"title":"Recycling efficiency optimization of tungsten-filled Vinyl-Methyl-Silicone-based flexible gamma ray shielding materials","authors":"Tao Wu, Jie Wang, Qiuyu Sun, Yifan Yang, Qingyu Si, Chenyu Liang, Guoming Liu, Aijun Mi, Sheng Wang","doi":"10.1016/j.net.2024.08.032","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.032","url":null,"abstract":"Tungsten has been widely used for gamma-ray and X-ray radiation shielding, which is one of the main elements of shielding materials. Compared with traditional lead-containing shielding materials, tungsten-containing shielding materials have several advantages, such as good chemical stability, a high melting point and relative environmental friendliness. Considering the recycling of resources, the optimization of pyrolysis temperature and pyrolysis duration of tungsten-filled Vinyl-Methyl-Silicone-based flexible shielding materials needs to be studied. In this paper, these tungsten-filled Vinyl-Methyl-Silicone-based flexible shielding materials were initially recycled using pyrolysis. Subsequently, the crystal structures, surface chemical states and the tungsten concentration after pyrolysis in an argon atmosphere were characterized. In order to increase the tungsten recycling rate, the pyrolyzed samples were further recycled using the ultrasonic cleaning method. Furthermore, the influence of ultrasonic cleaning on tungsten recycling rate and surface morphologies was characterized and analyzed. It is found that the tungsten recycling rate of tungsten-filled Vinyl-Methyl-Silicone based flexible gamma/X-ray shielding material was around 69.9 wt%-81.6 wt% by using the pyrolysis method, while the recycling rate of tungsten can exceed 90.0 wt% by ultrasonic cleaning after pyrolysis.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The urgent requirement for sustainable and dependable energy sources has stimulated an increased fascination with precisely forecasting nuclear energy generation. This work utilizes sophisticated regression modeling approaches, namely XGBoost, to predict nuclear energy generation by leveraging economic indices such as Gross Domestic Product (GDP). Each model's prediction accuracy has been evaluated by examining historical data on nuclear energy output and GDP from various locations. Here, measures such as mean squared error (MSE) and coefficient of determination (R2) to analyze their effectiveness have been used. The results of this study demonstrate that the XGBoost model outperforms standard regression approaches, showing greater R2 values and lower MSE scores. Furthermore, the consequences of these discoveries for the development of energy policy offer possible directions for future study in energy forecasting. This study provides useful insights for energy planners and policymakers, enabling a more profound comprehension of the complex relationship between economic indicators and nuclear energy generation.
{"title":"Advancing nuclear energy forecasting: Exploring regression modeling techniques for improved accuracy","authors":"Anjali Nighoskar, Preeti Chaurasia, Nagendra Singh","doi":"10.1016/j.net.2024.08.013","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.013","url":null,"abstract":"The urgent requirement for sustainable and dependable energy sources has stimulated an increased fascination with precisely forecasting nuclear energy generation. This work utilizes sophisticated regression modeling approaches, namely XGBoost, to predict nuclear energy generation by leveraging economic indices such as Gross Domestic Product (GDP). Each model's prediction accuracy has been evaluated by examining historical data on nuclear energy output and GDP from various locations. Here, measures such as mean squared error (MSE) and coefficient of determination (R2) to analyze their effectiveness have been used. The results of this study demonstrate that the XGBoost model outperforms standard regression approaches, showing greater R2 values and lower MSE scores. Furthermore, the consequences of these discoveries for the development of energy policy offer possible directions for future study in energy forecasting. This study provides useful insights for energy planners and policymakers, enabling a more profound comprehension of the complex relationship between economic indicators and nuclear energy generation.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-16DOI: 10.1016/j.net.2024.08.030
Soohyeok Lee, Hyoungtaek Kim, Hwijoon Jung, Kyung Taek Lim
This paper explores the implementation of machine learning-based algorithms for TL dose assessment. It focuses on the radiation field classification, performance quotient evaluation, and shallow and deep dose equivalent assessment of ANN and LGBM, in comparison to the traditional method of DT. We evaluate these algorithms based on the element response data measured by TLD. A data set was built for training, and the base element responses of test categories were amplified, and normalized to 1 mSv Cs-137 within the range of ±3 %. Both algorithms consist of five subset models for classifying radiation fields and identifying ratios of mixed fields. The LGBM showed the best accuracy in classifying considered radiation fields and the lowest performance quotients. By comparing the tolerance levels of deep dose and shallow dose equivalents among the three algorithms, the LGBM yields the smallest difference between the predicted and true dose equivalents. This smaller difference implies the LGBM offers the least bias and standard deviation in the expected value, giving higher accuracy and precision in dose assessment over the traditional DT method. The findings from this study further contribute to the adoption of ML-based algorithms for TL dose assessment, underscoring its importance in the field.
{"title":"Comparative analysis of machine learning-based dose assessment algorithms for TL dosimetry","authors":"Soohyeok Lee, Hyoungtaek Kim, Hwijoon Jung, Kyung Taek Lim","doi":"10.1016/j.net.2024.08.030","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.030","url":null,"abstract":"This paper explores the implementation of machine learning-based algorithms for TL dose assessment. It focuses on the radiation field classification, performance quotient evaluation, and shallow and deep dose equivalent assessment of ANN and LGBM, in comparison to the traditional method of DT. We evaluate these algorithms based on the element response data measured by TLD. A data set was built for training, and the base element responses of test categories were amplified, and normalized to 1 mSv Cs-137 within the range of ±3 %. Both algorithms consist of five subset models for classifying radiation fields and identifying ratios of mixed fields. The LGBM showed the best accuracy in classifying considered radiation fields and the lowest performance quotients. By comparing the tolerance levels of deep dose and shallow dose equivalents among the three algorithms, the LGBM yields the smallest difference between the predicted and true dose equivalents. This smaller difference implies the LGBM offers the least bias and standard deviation in the expected value, giving higher accuracy and precision in dose assessment over the traditional DT method. The findings from this study further contribute to the adoption of ML-based algorithms for TL dose assessment, underscoring its importance in the field.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-16DOI: 10.1016/j.net.2024.08.029
Xin Wang, Ze Xu, Yulan Liu, Biao Wang
The elastoplastic mechanical behavior of Zircaloy-4 (Zr-4) cladding, coated with chromium (Cr) or FeCrAl on its surface, is explored under the coupled effects of multi-field coupling. Utilizing the Finite Element Software ABAQUS, simulations are conducted to calculate the evolution of stress and strain over two complete fuel cycles. Comparisons are drawn between the coated and uncoated Zircaloy-4 cladding materials. The results indicate that the application of surface coatings significantly mitigates stress levels in the cladding during the first fuel cycle. During the second fuel cycle, all three types of cladding exhibit relatively minor plastic strain, which is attributed to the unloading and reloading process between cycles. Notably, the plastic zone propagates from the interior to the exterior of the cladding. When compared to traditional Zircaloy-4 cladding, the coated cladding exhibits improved elastoplastic mechanical behavior. The operational mechanism of the coating for different stresses in cylindrical coordinates and its response to unloading and reloading cycles are also investigated. Specifically, the coated claddings exhibit an evident delay in reaching full plasticity compared to uncoated claddings. Furthermore, FeCrAl coating material initially shows good performance, and it needs to be verified in more aspects in the future. Results and Conclusions in this paper can provide reference and guidance for future experiments.
{"title":"Elastoplastic mechanical behavior analysis of surface-coated Zircaloy-4 cladding under multi-field coupling","authors":"Xin Wang, Ze Xu, Yulan Liu, Biao Wang","doi":"10.1016/j.net.2024.08.029","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.029","url":null,"abstract":"The elastoplastic mechanical behavior of Zircaloy-4 (Zr-4) cladding, coated with chromium (Cr) or FeCrAl on its surface, is explored under the coupled effects of multi-field coupling. Utilizing the Finite Element Software ABAQUS, simulations are conducted to calculate the evolution of stress and strain over two complete fuel cycles. Comparisons are drawn between the coated and uncoated Zircaloy-4 cladding materials. The results indicate that the application of surface coatings significantly mitigates stress levels in the cladding during the first fuel cycle. During the second fuel cycle, all three types of cladding exhibit relatively minor plastic strain, which is attributed to the unloading and reloading process between cycles. Notably, the plastic zone propagates from the interior to the exterior of the cladding. When compared to traditional Zircaloy-4 cladding, the coated cladding exhibits improved elastoplastic mechanical behavior. The operational mechanism of the coating for different stresses in cylindrical coordinates and its response to unloading and reloading cycles are also investigated. Specifically, the coated claddings exhibit an evident delay in reaching full plasticity compared to uncoated claddings. Furthermore, FeCrAl coating material initially shows good performance, and it needs to be verified in more aspects in the future. Results and Conclusions in this paper can provide reference and guidance for future experiments.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-15DOI: 10.1016/j.net.2024.08.023
Haoxiang Li, Wei Zheng, Bin Du, Huang Zhang, Huaqiang Yin, Xuedong He, Tao Ma, Xingtuan Yang
Air ingress accident is one of the typical accident conditions in Very High Temperature Reactors (VHTRs). This work investigates the oxidation kinetics, corrosion behavior and mechanism of Inconel 617 alloy in different oxygen concentration atmospheres under air ingress accident. The impact of O concentration and oxidation time of the alloy corrosion is investigated. A gas chromatograph was used to measure the impurity content in real time during the helium experiments. After the experiments, the alloys were characterized by electronic balance, were analyzed by Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), X-ray diffraction (XRD) and carbon and sulfur analyzer. The results show that: the Inconel 617 alloy undergoes similar oxidation behavior and the degree of oxidation is very close in three groups of atmospheres with large differences in oxygen content; the alloy should show two oxidation mechanisms, linear oxidation and parabolic oxidation, during the oxidation process; the parabolic rate constant and of the alloy is a constant value and does not vary with large changes in oxygen concentration, but when the experimental temperature changes, the oxidation rate constants of the alloy change, and the lowering of the temperature leads to the lowering of the oxidation rate constants; When experimental temperature is at 950 °C, the alloy continues to undergo a “microclimatic reaction” in the atmosphere of He-ppmO, and the microclimatic reaction disappears when the experimental temperature is lowered to 750 °C; In He-ppmO environment, gas chromatograph can be used instead of thermogravimetric analyzer for real-time monitoring.
{"title":"Corrosion studies of Inconel 617 in high temperature air and He-ppmO2 atmospheres","authors":"Haoxiang Li, Wei Zheng, Bin Du, Huang Zhang, Huaqiang Yin, Xuedong He, Tao Ma, Xingtuan Yang","doi":"10.1016/j.net.2024.08.023","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.023","url":null,"abstract":"Air ingress accident is one of the typical accident conditions in Very High Temperature Reactors (VHTRs). This work investigates the oxidation kinetics, corrosion behavior and mechanism of Inconel 617 alloy in different oxygen concentration atmospheres under air ingress accident. The impact of O concentration and oxidation time of the alloy corrosion is investigated. A gas chromatograph was used to measure the impurity content in real time during the helium experiments. After the experiments, the alloys were characterized by electronic balance, were analyzed by Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), X-ray diffraction (XRD) and carbon and sulfur analyzer. The results show that: the Inconel 617 alloy undergoes similar oxidation behavior and the degree of oxidation is very close in three groups of atmospheres with large differences in oxygen content; the alloy should show two oxidation mechanisms, linear oxidation and parabolic oxidation, during the oxidation process; the parabolic rate constant and of the alloy is a constant value and does not vary with large changes in oxygen concentration, but when the experimental temperature changes, the oxidation rate constants of the alloy change, and the lowering of the temperature leads to the lowering of the oxidation rate constants; When experimental temperature is at 950 °C, the alloy continues to undergo a “microclimatic reaction” in the atmosphere of He-ppmO, and the microclimatic reaction disappears when the experimental temperature is lowered to 750 °C; In He-ppmO environment, gas chromatograph can be used instead of thermogravimetric analyzer for real-time monitoring.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, the thermal characteristics and steady-state temperatures (SST) of CPU and FPGA of electronic system in nuclear power plant are explored. Finite element analysis is performed to simulate the test process. Furthermore, three machine learning algorithms are used to predict chips temperatures at different operating conditions. It is found that when the ambient temperature is 20 °C and all the fans are power-off, the SST of the CPU and FPGA reaches 75 °C and 72 °C, respectively. While when the fans are power-on, the SST of the CPU and FPGA drops to 37.5 °C and 33 °C. When the ambient temperature increases to 55 °C and all the fans are power-on, the SST of the CPU and FPGA is 72.3 °C and 68.2 °C, respectively. The finite element model is verified and used to generate test data. Three machine learning models are verified by predicting the SST of CPU and FPGA under different operating conditions. It is found that M-SVR has better prediction ability than DT and ANN. The findings can be used for chip reliability evaluation of other electronic system devices, and provide a new method for predicting the possible steady-state temperature of chips under different service conditions.
{"title":"Investigation on the thermal characteristics of electronic system and prediction of chip temperature by machine learning","authors":"Fanyu Wang, Dongwei Wang, Qiang Deng, Hao Yan, Qi Chen, Yang Zhao","doi":"10.1016/j.net.2024.08.028","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.028","url":null,"abstract":"In this work, the thermal characteristics and steady-state temperatures (SST) of CPU and FPGA of electronic system in nuclear power plant are explored. Finite element analysis is performed to simulate the test process. Furthermore, three machine learning algorithms are used to predict chips temperatures at different operating conditions. It is found that when the ambient temperature is 20 °C and all the fans are power-off, the SST of the CPU and FPGA reaches 75 °C and 72 °C, respectively. While when the fans are power-on, the SST of the CPU and FPGA drops to 37.5 °C and 33 °C. When the ambient temperature increases to 55 °C and all the fans are power-on, the SST of the CPU and FPGA is 72.3 °C and 68.2 °C, respectively. The finite element model is verified and used to generate test data. Three machine learning models are verified by predicting the SST of CPU and FPGA under different operating conditions. It is found that M-SVR has better prediction ability than DT and ANN. The findings can be used for chip reliability evaluation of other electronic system devices, and provide a new method for predicting the possible steady-state temperature of chips under different service conditions.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-14DOI: 10.1016/j.net.2024.08.025
Danwoo Ko, Seunguk Cheon, Jiyoung Kim, Seungmin Lee, Seung Min Woo
There is an argument that the Comprehensive Safeguards Agreement (CSA) should be applied to the milling process, which is the first stage of nuclear fuel cycle, to reduce the possibility of nuclear proliferation. Therefore, this study aims to propose new and conceptual safeguards applicable to milling facilities and design Nuclear Material Accountancy for its application. Mill tailings reach a secular equilibrium state. While approaching this equilibrium state, the ratio of each isotope changes. First, the Bateman equation was used to analyze this phenomenon and evaluate the feasibility of utilizing the specific isotope ratio to track undeclared nuclear activities. Second, the gamma spectrum analysis of mill tailings was conducted using the Monte Carlo N-Particle Code to validate undeclared nuclear activities. This study shows that the ratio of U-235/Th-234 and U-235/Pa-234m can estimate the production time within a year. Furthermore, gamma spectrum analysis of mill tailings revealed visible differences in the low-energy region due to the decay of Th-234. Finally, a conceptual Material Balance Area, Key Measurement Points, and Material Balance Period for milling facilities were designed to apply CSA. It is anticipated that applying CSA to milling facilities could enhance not only the nuclear fuel cycles but also nuclear non-proliferation system.
{"title":"Conceptual safeguards method proposal for milling facilities based on nuclear isotopic ratios in uranium mill tailings","authors":"Danwoo Ko, Seunguk Cheon, Jiyoung Kim, Seungmin Lee, Seung Min Woo","doi":"10.1016/j.net.2024.08.025","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.025","url":null,"abstract":"There is an argument that the Comprehensive Safeguards Agreement (CSA) should be applied to the milling process, which is the first stage of nuclear fuel cycle, to reduce the possibility of nuclear proliferation. Therefore, this study aims to propose new and conceptual safeguards applicable to milling facilities and design Nuclear Material Accountancy for its application. Mill tailings reach a secular equilibrium state. While approaching this equilibrium state, the ratio of each isotope changes. First, the Bateman equation was used to analyze this phenomenon and evaluate the feasibility of utilizing the specific isotope ratio to track undeclared nuclear activities. Second, the gamma spectrum analysis of mill tailings was conducted using the Monte Carlo N-Particle Code to validate undeclared nuclear activities. This study shows that the ratio of U-235/Th-234 and U-235/Pa-234m can estimate the production time within a year. Furthermore, gamma spectrum analysis of mill tailings revealed visible differences in the low-energy region due to the decay of Th-234. Finally, a conceptual Material Balance Area, Key Measurement Points, and Material Balance Period for milling facilities were designed to apply CSA. It is anticipated that applying CSA to milling facilities could enhance not only the nuclear fuel cycles but also nuclear non-proliferation system.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-13DOI: 10.1016/j.net.2024.08.020
Hyeongjin Byeon, Ugyu Jeong, Jaeyeong Park
Homogeneity is an important factor for ensuring the structural stability of solidified radioactive waste, and the most effective approach for assessing its homogeneity is by performing compressive strength measurements using the minimum amount of coring specimens. The efficiency of detecting inhomogeneous waste is affected by the coring position and number of coring positions. However, no guidelines exist for coring solidified waste for compressive-strength tests. Therefore, this study compared uniform, random, and quasi-Monte Carlo sampling methods to determine the most effective core position. Further, the effects of different sampling amounts on the detection rate of inhomogeneous solidified waste were observed, and the detection rate of the inhomogeneous waste was obtained by modeling the coring procedure of solidified radioactive waste using MATLAB. Thus, a sampling method and a method for increasing the specimen amount, both of which can efficiently detect inhomogeneous waste during compressive strength tests, were presented in this paper. The results of this study can be applied as background data for developing homogeneity assessment guidelines for solidified radioactive waste.
{"title":"Statistical sampling method to verify the homogeneity of full-scale cement-solidified radioactive waste","authors":"Hyeongjin Byeon, Ugyu Jeong, Jaeyeong Park","doi":"10.1016/j.net.2024.08.020","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.020","url":null,"abstract":"Homogeneity is an important factor for ensuring the structural stability of solidified radioactive waste, and the most effective approach for assessing its homogeneity is by performing compressive strength measurements using the minimum amount of coring specimens. The efficiency of detecting inhomogeneous waste is affected by the coring position and number of coring positions. However, no guidelines exist for coring solidified waste for compressive-strength tests. Therefore, this study compared uniform, random, and quasi-Monte Carlo sampling methods to determine the most effective core position. Further, the effects of different sampling amounts on the detection rate of inhomogeneous solidified waste were observed, and the detection rate of the inhomogeneous waste was obtained by modeling the coring procedure of solidified radioactive waste using MATLAB. Thus, a sampling method and a method for increasing the specimen amount, both of which can efficiently detect inhomogeneous waste during compressive strength tests, were presented in this paper. The results of this study can be applied as background data for developing homogeneity assessment guidelines for solidified radioactive waste.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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