Pub Date : 2024-08-26DOI: 10.1016/j.net.2024.08.046
Jong-Bae Hwang, Injin Sa, Eung-Seon Kim, Dong-Hyun Lee
High temperature mechanical properties of diffusion welded Alloy 800H was investigated to fabricate a printed circuit heat exchanger (PCHE) for high temperature reactor (HTR) systems. Surface treatment was performed on Alloy 800H to transform the solubility product () to exceed the reaction quotient (). The surface treatment facilitated the grain boundary migration across the interface. The yield strengths exceeded the values described in ASME Section III Division 5 Table HBB-I-14.5 up to 760 °C, while the tensile strengths were comparable to Table HBB-3225-1 up to 700 °C. At 760 °C, the tensile strength was ∼30 MPa lower than the code. The stress-to-rupture values exceeded the expected minimum stress-to-rupture values of Alloy 800H described in Table HBB-I-14.6C. The ductility of the diffusion weldment acquired from the tensile test was comparable to the as-received Alloy 800H. Meanwhile, the formation of the secondary precipitates on the interface during the stress-to-rupture test deteriorated the ductility of the diffusion weldment, which induced intergranular fracture.
{"title":"High temperature mechanical properties of diffusion welded alloy 800H","authors":"Jong-Bae Hwang, Injin Sa, Eung-Seon Kim, Dong-Hyun Lee","doi":"10.1016/j.net.2024.08.046","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.046","url":null,"abstract":"High temperature mechanical properties of diffusion welded Alloy 800H was investigated to fabricate a printed circuit heat exchanger (PCHE) for high temperature reactor (HTR) systems. Surface treatment was performed on Alloy 800H to transform the solubility product () to exceed the reaction quotient (). The surface treatment facilitated the grain boundary migration across the interface. The yield strengths exceeded the values described in ASME Section III Division 5 Table HBB-I-14.5 up to 760 °C, while the tensile strengths were comparable to Table HBB-3225-1 up to 700 °C. At 760 °C, the tensile strength was ∼30 MPa lower than the code. The stress-to-rupture values exceeded the expected minimum stress-to-rupture values of Alloy 800H described in Table HBB-I-14.6C. The ductility of the diffusion weldment acquired from the tensile test was comparable to the as-received Alloy 800H. Meanwhile, the formation of the secondary precipitates on the interface during the stress-to-rupture test deteriorated the ductility of the diffusion weldment, which induced intergranular fracture.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207230","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 : 2024-08-26DOI: 10.1016/j.net.2024.08.050
Jin-Mok Hur, Jungho Hur, Yung-Zun Cho, Chang Hwa Lee
The separation of high heat load fission products, such as alkaline earth metals, from nuclear spent fuel can significantly reduce the burden of spent fuel disposal. This study investigates the feasibility of separating strontium and barium from light water reactor spent fuel through non-aqueous processes. Process flows were developed for treating spent nuclear fuel by heating it at high temperatures to remove volatile nuclides, followed by chlorination with a chlorinating agent. The chlorinated products were then treated with a precipitating agent in LiCl-KCl molten salt for further separation. The remaining liquid was distilled to recover strontium and barium. Thermodynamic equilibrium calculations were conducted for the process flows. Under the conditions of the process flows, the chlorinating agents MgCl and NHCl both converted SrO and BaO entirely into SrCl and BaCl, respectively. The precipitating agent LiCO exhibited superior separation effectiveness compared to LiPO. Thermodynamic calculations indicate that strontium and barium recovered by MgCl chlorination, LiCO precipitation, and distillation will contain 0.18 %, 1.06 %, and 0.32 % impurities in terms of mass, radioactivity, and decay heat, respectively.
{"title":"Thermodynamic study on the separation of strontium and barium from LWR spent fuel","authors":"Jin-Mok Hur, Jungho Hur, Yung-Zun Cho, Chang Hwa Lee","doi":"10.1016/j.net.2024.08.050","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.050","url":null,"abstract":"The separation of high heat load fission products, such as alkaline earth metals, from nuclear spent fuel can significantly reduce the burden of spent fuel disposal. This study investigates the feasibility of separating strontium and barium from light water reactor spent fuel through non-aqueous processes. Process flows were developed for treating spent nuclear fuel by heating it at high temperatures to remove volatile nuclides, followed by chlorination with a chlorinating agent. The chlorinated products were then treated with a precipitating agent in LiCl-KCl molten salt for further separation. The remaining liquid was distilled to recover strontium and barium. Thermodynamic equilibrium calculations were conducted for the process flows. Under the conditions of the process flows, the chlorinating agents MgCl and NHCl both converted SrO and BaO entirely into SrCl and BaCl, respectively. The precipitating agent LiCO exhibited superior separation effectiveness compared to LiPO. Thermodynamic calculations indicate that strontium and barium recovered by MgCl chlorination, LiCO precipitation, and distillation will contain 0.18 %, 1.06 %, and 0.32 % impurities in terms of mass, radioactivity, and decay heat, respectively.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207229","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}
This paper presents an innovative design of a steel-reinforced concrete (SRC) column-reinforced concrete (RC) slab joint based on a concept of the strong column and weak slab. In this study, two 1:2 reduced scale SRC column-RC slab joint specimens are designed and fabricated for horizontal cyclic loading tests based on side slab-column joints of an auxiliary plant of a nuclear power plant. In order to ensure the ease of construction and stability of the connection between the reinforcement and the section steel, one structure (SR-2) with steel sleeves welded to the section steel and connected to the reinforcement in the joint area and the other structure (SR-1) with a stiffened steel plate (SSP) in the connection area on the basis of SR-2 were fabricated and tested in order to investigate the structural strengthening the joint. Based on the test results, the damage modes, hysteresis performance, energy dissipation capacity and stiffness degradation of the specimens were studied. A finite element analysis (FEA) model was developed and verified with the experimental results. The verified FEA model was used for parametrical study on effects of thickness, outer dimensions of SSP, a longitudinal reinforcement ratio in the RC slab and an axial pressure ratio. The test results show that the damage mode of specimens is shear failure at the RC slab and the damage of the SRC column is minor, which is in line with the design concept of the strong column and weak slab. The parametric study shows that increasing the thickness and outer size of SSP can improve the load-bearing capacity and initial stiffness of joints.
{"title":"Experimental and numerical study on seismic behaviors of SRC column-RC slab joints in NPP","authors":"Dayang Wang, Qiang Liu, Yuanqi Song, Yong Zhu, Yongshan Zhang","doi":"10.1016/j.net.2024.08.045","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.045","url":null,"abstract":"This paper presents an innovative design of a steel-reinforced concrete (SRC) column-reinforced concrete (RC) slab joint based on a concept of the strong column and weak slab. In this study, two 1:2 reduced scale SRC column-RC slab joint specimens are designed and fabricated for horizontal cyclic loading tests based on side slab-column joints of an auxiliary plant of a nuclear power plant. In order to ensure the ease of construction and stability of the connection between the reinforcement and the section steel, one structure (SR-2) with steel sleeves welded to the section steel and connected to the reinforcement in the joint area and the other structure (SR-1) with a stiffened steel plate (SSP) in the connection area on the basis of SR-2 were fabricated and tested in order to investigate the structural strengthening the joint. Based on the test results, the damage modes, hysteresis performance, energy dissipation capacity and stiffness degradation of the specimens were studied. A finite element analysis (FEA) model was developed and verified with the experimental results. The verified FEA model was used for parametrical study on effects of thickness, outer dimensions of SSP, a longitudinal reinforcement ratio in the RC slab and an axial pressure ratio. The test results show that the damage mode of specimens is shear failure at the RC slab and the damage of the SRC column is minor, which is in line with the design concept of the strong column and weak slab. The parametric study shows that increasing the thickness and outer size of SSP can improve the load-bearing capacity and initial stiffness of joints.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207231","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 : 2024-08-26DOI: 10.1016/j.net.2024.08.039
Ke Wu, Jun Zhang, Yong Cheng, Qingxi Yang, Hongtao Pan, Tao Wang, Aiming Liu, Hao Han
This paper proposed a framework of a dual-arm-based robotic maintenance system, including visual recognition, trajectory planning, force feedback control and master–slave control. To meet the requirements of automated maintenance, we proposed an improved design for the structures of the first wall tiles and support boards, and established a complete communication structure for the maintenance system that can adapt to different hardware versions. Based on the proposed framework, an experimental platform with dual-arm manipulator was established to demonstrate the maintenance scenario of the FW of the blanket in Vacuum Vessel (VV). The experimental result verified the feasibility of automated robotic maintenance system applied to the future fusion reactor.
{"title":"The design and implementation of automated maintenance system for the first-wall based on dual-arm manipulator","authors":"Ke Wu, Jun Zhang, Yong Cheng, Qingxi Yang, Hongtao Pan, Tao Wang, Aiming Liu, Hao Han","doi":"10.1016/j.net.2024.08.039","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.039","url":null,"abstract":"This paper proposed a framework of a dual-arm-based robotic maintenance system, including visual recognition, trajectory planning, force feedback control and master–slave control. To meet the requirements of automated maintenance, we proposed an improved design for the structures of the first wall tiles and support boards, and established a complete communication structure for the maintenance system that can adapt to different hardware versions. Based on the proposed framework, an experimental platform with dual-arm manipulator was established to demonstrate the maintenance scenario of the FW of the blanket in Vacuum Vessel (VV). The experimental result verified the feasibility of automated robotic maintenance system applied to the future fusion reactor.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207228","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 : 2024-08-24DOI: 10.1016/j.net.2024.08.047
Qianxu Wang, Yuanlai Xie, Huihui Hong, Yang Zhu, Fang Wang, Kun Tian, Bin Li
As an important component of Negative ion based Neutral Beam Injector (NNBI), the cryopump mainly provides a suitable vacuum environment for beam generation and transmission. In the paper, Liquid nitrogen (LN2) pipe structure models of two cryopumps were established for simulation and experimental studies. Thermal analysis of the thermal radiation shielding baffle (LN2 cooling) was carried out by Ansys steady-state thermal analysis software, while Fluent was used to simulate the two-phase flow in the LN2 pipeline, then the pressure drops, temperature, velocity, gas-phase volume fraction, and other parameters of the two pipeline structures were analyzed and compared. The simulation results show that the optimized structure B can reduce the pressure drop by 3 bar, the outlet temperature of structure A is 78.8 K, the outlet temperature of structure B is 79.2 K, the temperature difference is 0.4 K. The outlet velocity increases from 2.067 m/s to 4.947 m/s for Structure A, and from 1.096 m/s to 6.614 m/s for Structure B. The experiment results show that the outlet temperature of structure A is 79.4 K, meanwhile the outlet temperature of structure B is 80.1 K, the optimized structure B can reduce the pressure drop about 3 bar.
作为负离子中性束注入器（NNBI）的重要组成部分，低温泵主要为束流的产生和传输提供合适的真空环境。本文建立了两个低温泵的液氮（LN2）管道结构模型，并进行了模拟和实验研究。利用 Ansys 稳态热分析软件对热辐射屏蔽挡板（LN2 冷却）进行了热分析，同时利用 Fluent 对 LN2 管道中的两相流动进行了模拟，然后对两种管道结构的压降、温度、速度、气相体积分数等参数进行了分析和比较。模拟结果表明，优化后的结构 B 可使压降降低 3 bar，结构 A 的出口温度为 78.8 K，结构 B 的出口温度为 79.2 K，温差为 0.4 K，出口速度从结构 A 的 2.067 m/s 增加到 4.实验结果表明，结构 A 的出口温度为 79.4 K，而结构 B 的出口温度为 80.1 K，优化后的结构 B 可减少压降约 3 bar。
{"title":"Analysis and optimization of LN2 two-phase flow in CRAFT NNBI cryopump","authors":"Qianxu Wang, Yuanlai Xie, Huihui Hong, Yang Zhu, Fang Wang, Kun Tian, Bin Li","doi":"10.1016/j.net.2024.08.047","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.047","url":null,"abstract":"As an important component of Negative ion based Neutral Beam Injector (NNBI), the cryopump mainly provides a suitable vacuum environment for beam generation and transmission. In the paper, Liquid nitrogen (LN2) pipe structure models of two cryopumps were established for simulation and experimental studies. Thermal analysis of the thermal radiation shielding baffle (LN2 cooling) was carried out by Ansys steady-state thermal analysis software, while Fluent was used to simulate the two-phase flow in the LN2 pipeline, then the pressure drops, temperature, velocity, gas-phase volume fraction, and other parameters of the two pipeline structures were analyzed and compared. The simulation results show that the optimized structure B can reduce the pressure drop by 3 bar, the outlet temperature of structure A is 78.8 K, the outlet temperature of structure B is 79.2 K, the temperature difference is 0.4 K. The outlet velocity increases from 2.067 m/s to 4.947 m/s for Structure A, and from 1.096 m/s to 6.614 m/s for Structure B. The experiment results show that the outlet temperature of structure A is 79.4 K, meanwhile the outlet temperature of structure B is 80.1 K, the optimized structure B can reduce the pressure drop about 3 bar.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207241","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}
Neutral beam injection is one of the effective heating methods in the field of magnetic confinement fusion, and neutralization is the most crucial link in the case of negative ions. To further increase the neutral beam injection power, improve the long pulse operation capability, and optimize the efficiency of the NNBI system, further research and verification about the neutralization mode are needed. Theoretically, photoneutralization can achieve more than 90 % neutralization efficiency. However, maintaining stable operation of the megawatt laser cavity over extended periods poses corresponding challenges. Additionally, the cost associated with laser target surpasses the benefit gained from increased neutralization efficiency, leading to its lack of practical application thus far. This paper proposes a solution to these issues by designing a single-channel, multi-fold photoneutralization verification system utilizing the CRAFT NNBI one-quarter and one-half size negative source test equipment. An outline of the system's test and diagnostics approach is provided. Key parameters such as laser target thickness, negative ion energy, beam shape and efficiency of the photoneutralization system are numerically calculated. Combined with the experimental data of the negative source test platform, theoretical calculations show that the neutralization efficiency can achieve 63 % with the system efficiency exceeding 40 %. Even by increasing the incident laser power or the number of reflections, neutralization efficiency can be increased to 95 %, with a simultaneous increase in system efficiency to 60 %. Maintaining efficiency while increasing incident laser power could reduce the number of reflections to approximately ten, reaching an acceptable threshold. However, this adjustment will increase the irradiation density of a single mirror from 660W/mm increases to 3000W/mm. This paper methodically designs a practical laser neutralization verification platform, which is expected to substantially improve the neutralization efficiency, and facilitate practical application and validation.
{"title":"Conceptional design of photoneutralization test system for negative ion-based neutral beam injection","authors":"Hui-hui Hong, Li-zhen Liang, Yuan-lai Xie, Qian-xu Wang, Zhuo Pan, Yao Jiang","doi":"10.1016/j.net.2024.08.024","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.024","url":null,"abstract":"Neutral beam injection is one of the effective heating methods in the field of magnetic confinement fusion, and neutralization is the most crucial link in the case of negative ions. To further increase the neutral beam injection power, improve the long pulse operation capability, and optimize the efficiency of the NNBI system, further research and verification about the neutralization mode are needed. Theoretically, photoneutralization can achieve more than 90 % neutralization efficiency. However, maintaining stable operation of the megawatt laser cavity over extended periods poses corresponding challenges. Additionally, the cost associated with laser target surpasses the benefit gained from increased neutralization efficiency, leading to its lack of practical application thus far. This paper proposes a solution to these issues by designing a single-channel, multi-fold photoneutralization verification system utilizing the CRAFT NNBI one-quarter and one-half size negative source test equipment. An outline of the system's test and diagnostics approach is provided. Key parameters such as laser target thickness, negative ion energy, beam shape and efficiency of the photoneutralization system are numerically calculated. Combined with the experimental data of the negative source test platform, theoretical calculations show that the neutralization efficiency can achieve 63 % with the system efficiency exceeding 40 %. Even by increasing the incident laser power or the number of reflections, neutralization efficiency can be increased to 95 %, with a simultaneous increase in system efficiency to 60 %. Maintaining efficiency while increasing incident laser power could reduce the number of reflections to approximately ten, reaching an acceptable threshold. However, this adjustment will increase the irradiation density of a single mirror from 660W/mm increases to 3000W/mm. This paper methodically designs a practical laser neutralization verification platform, which is expected to substantially improve the neutralization efficiency, and facilitate practical application and validation.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207242","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 : 2024-08-20DOI: 10.1016/j.net.2024.08.038
Jaeseok Yoo, Young-jin Oh, Nam-hyun Kim, Soo-ill Lee, Jaepil Ko
As the proportion of renewable energy has increased in the national power grid of Republic of Korea, various efforts are needed to maintain the stability of total power generation. All kinds of power plants, including nuclear power, must notify the grid operation organization of their expected transmission power. Even in NPPs, the accuracy of transmission power forecasting can increase the plant owner's economic benefits as well as the stability of the power grid. The transmission power of a NPP is affected by various plant conditions and environmental conditions, including the temperature of circulating water (sea water). In this study, we explored how to effectively handle the long-term dependence problem and various data characteristics to increase the forecasting accuracy of transmission power in NPPs by introducing a Seq2Seq model with an encoder-decoder structure and an attention mechanism, beyond traditional time series deep learning models, especially LSTM. This approach will improve the accuracy of transmission power forecasting and contribute to a stable power supply. Additionally, the model is expected to provide a realistic and practical solution for the power demand response of power plants.
{"title":"Multi-step multivariate forecasting of transmission power in NPPs using operational and meteorological data","authors":"Jaeseok Yoo, Young-jin Oh, Nam-hyun Kim, Soo-ill Lee, Jaepil Ko","doi":"10.1016/j.net.2024.08.038","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.038","url":null,"abstract":"As the proportion of renewable energy has increased in the national power grid of Republic of Korea, various efforts are needed to maintain the stability of total power generation. All kinds of power plants, including nuclear power, must notify the grid operation organization of their expected transmission power. Even in NPPs, the accuracy of transmission power forecasting can increase the plant owner's economic benefits as well as the stability of the power grid. The transmission power of a NPP is affected by various plant conditions and environmental conditions, including the temperature of circulating water (sea water). In this study, we explored how to effectively handle the long-term dependence problem and various data characteristics to increase the forecasting accuracy of transmission power in NPPs by introducing a Seq2Seq model with an encoder-decoder structure and an attention mechanism, beyond traditional time series deep learning models, especially LSTM. This approach will improve the accuracy of transmission power forecasting and contribute to a stable power supply. Additionally, the model is expected to provide a realistic and practical solution for the power demand response of power plants.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207243","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 : 2024-08-19DOI: 10.1016/j.net.2024.08.033
P. Martinez-Reviriego, N. Fuster-Martínez, D. Esperante, M. Boronat, B. Gimeno, C. Blanch, D. González-Iglesias, P. Martín-Luna, E. Martínez, A. Menendez, L. Pedraza, J. Fernández, J. Fuster, A. Grudiev, N. Catalan Lasheras, W. Wuensch
High-Gradient accelerating cavities are one of the main research lines in the development of compact linear accelerators. However, the operation of such accelerating cavities is currently limited by non-linear electromagnetic effects that are intensified at high electric fields, such as RF breakdowns, dark currents and radiation. A novel normal-conducting High Gradient S-band Backward Travelling Wave accelerating cavity for medical application (v = 0.38c) has been designed and constructed at CERN with a design gradient of 50 MV/m. In this paper, the high-power performance studies of this novel design carried out at the IFIC high-power laboratory are presented, as well as the analysis of the conditioning parameters in combination with numerical simulations.
高梯度加速腔是开发紧凑型直线加速器的主要研究方向之一。然而，这种加速腔的运行目前受到非线性电磁效应的限制，这些效应在高电场下会加剧，如射频击穿、暗电流和辐射。欧洲核子研究中心（CERN）设计并建造了一个用于医疗应用的新型常导高梯度 S 波段后向游波加速腔（v = 0.38c），其设计梯度为 50 MV/m。本文介绍了在 IFIC 高功率实验室对这种新型设计进行的高功率性能研究，以及结合数值模拟对调节参数进行的分析。
{"title":"High-power performance studies of an S-band high-gradient accelerating cavity for medical applications","authors":"P. Martinez-Reviriego, N. Fuster-Martínez, D. Esperante, M. Boronat, B. Gimeno, C. Blanch, D. González-Iglesias, P. Martín-Luna, E. Martínez, A. Menendez, L. Pedraza, J. Fernández, J. Fuster, A. Grudiev, N. Catalan Lasheras, W. Wuensch","doi":"10.1016/j.net.2024.08.033","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.033","url":null,"abstract":"High-Gradient accelerating cavities are one of the main research lines in the development of compact linear accelerators. However, the operation of such accelerating cavities is currently limited by non-linear electromagnetic effects that are intensified at high electric fields, such as RF breakdowns, dark currents and radiation. A novel normal-conducting High Gradient S-band Backward Travelling Wave accelerating cavity for medical application (v = 0.38c) has been designed and constructed at CERN with a design gradient of 50 MV/m. In this paper, the high-power performance studies of this novel design carried out at the IFIC high-power laboratory are presented, as well as the analysis of the conditioning parameters in combination with numerical simulations.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207246","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 : 2024-08-19DOI: 10.1016/j.net.2024.08.034
Xin Liu, Shengyuan Yan, Xiaodan Zhang
The standardized plant analysis risk human reliability analysis (SPAR-H) method is widely used for human reliability analysis to adjust the nominal human error probability (HEP) by assigning different multipliers to the performance shaping factors (PSFs). Nevertheless, SPAR-H suffers from assuming PSFs to be independent without considering any overlaps and dependencies. Therefore, this study introduces a new systematic method to analyze the relationships among the PSFs in SPAR-H qualitatively and quantitatively to obtain more reasonable HEP estimation results. The proposed method comprises three primary aspects: 1) a regularized autoencoder for the denoising and feature extraction of expert evaluation results, 2) the weighted influence non-linear gauge system-based adversarial interpretive structure modeling (WINGS-AISM) method to analyze the relationships among the PSFs and construct their causal hierarchy, and 3) a new relative weighting system to modify the PSF multipliers based on this hierarchy. The results of experiments comparing the proposed method with conventional methods highlight that our method effectively reduces the double counting of overlapping PSFs in SPAR-H, providing more reasonable and accurate HEP estimation results.
{"title":"Accounting for dependencies among performance shaping factors in SPAR-H using a regularized autoencoder and WINGS-AISM","authors":"Xin Liu, Shengyuan Yan, Xiaodan Zhang","doi":"10.1016/j.net.2024.08.034","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.034","url":null,"abstract":"The standardized plant analysis risk human reliability analysis (SPAR-H) method is widely used for human reliability analysis to adjust the nominal human error probability (HEP) by assigning different multipliers to the performance shaping factors (PSFs). Nevertheless, SPAR-H suffers from assuming PSFs to be independent without considering any overlaps and dependencies. Therefore, this study introduces a new systematic method to analyze the relationships among the PSFs in SPAR-H qualitatively and quantitatively to obtain more reasonable HEP estimation results. The proposed method comprises three primary aspects: 1) a regularized autoencoder for the denoising and feature extraction of expert evaluation results, 2) the weighted influence non-linear gauge system-based adversarial interpretive structure modeling (WINGS-AISM) method to analyze the relationships among the PSFs and construct their causal hierarchy, and 3) a new relative weighting system to modify the PSF multipliers based on this hierarchy. The results of experiments comparing the proposed method with conventional methods highlight that our method effectively reduces the double counting of overlapping PSFs in SPAR-H, providing more reasonable and accurate HEP estimation results.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207245","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 : 2024-08-19DOI: 10.1016/j.net.2024.08.036
Xinbo Li, Jinxin Gong
This paper assesses the aging effects on the leak-tightness of containment under overpressure conditions. A global containment model and the detailed sub-models for the three main penetration regions in the containment are established. The main aging forms and mechanisms of containment are clarified, and corresponding simulation schemes are provided. Through numerical simulation, the impacts of different aging forms on the failure pressure of containment are discussed from a deterministic perspective. Finally, the fragility and functional failure probability of containment under different aging conditions are evaluated. When 60 years of concrete degradation and prestress loss are considered, the pressure capacities of equipment hatch, personnel airlock, and pipe penetration are reduced by approximately 5 %. Upon further considering steel liner corrosion, when the corrosion degree reaches 30 %, the pressure capacities of these regions are reduced by 24.37 %, 25.52 %, and 22.83 %, respectively. Within the scope of this study, the impact of steel liner corrosion on the risk of containment leakage is the most pronounced, whereas the impact of concrete degradation is minimal. If steel liner corrosion occurs simultaneously in three penetration regions, the whole containment will fail to meet the probabilistic performance goal when the corrosion degree reaches 30 %.
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