Pub Date : 2024-08-13DOI: 10.1016/j.net.2024.08.021
Seok-Min Hong, Chang Hwa Lee, Jae-Hwan Yang, Namcheol Kim
The continuous utilization of nuclear energy has led to the accumulation of spent nuclear fuel (SNF) containing uranium, transuranium, and fission products (FPs). Reprocessing and pyrochemical methods have shown the potential for SNF reuse, thereby reducing its environmental impact. Voloxidation, a pivotal step in SNF recycling, involves thermal treatment in an oxidizing atmosphere to enhance the reactivity. During voloxidation, Se-79, which is a FP with a long half-life, is released as SeO under oxidizing conditions, necessitating technologies to capture it. CaO pellets (CPs) were prepared to capture gaseous SeO. The effects of operating conditions on SeO capture performance were investigated. The CP reacts strongly with SeO to form CaSeO, exhibiting a high adsorption capacity of 17.5 mol kg and >99 % efficiency at 700 °C. The mechanical strength and thermal stability assessments indicate suitability for practical applications. Depending on the flow rate, the CP required for SeO capture was estimated when processing 1 t of SNF, thereby contributing to the design of effective SeO capture systems for safe and sustainable nuclear waste management.
核能的持续利用导致了含有铀、超铀和裂变产物（FPs）的乏核燃料（SNF）的积累。后处理和热化学方法显示了乏核燃料再利用的潜力，从而减少了其对环境的影响。氧化是 SNF 循环利用的关键步骤，包括在氧化气氛中进行热处理，以提高反应活性。在氧化过程中，Se-79 是一种半衰期较长的 FP，在氧化条件下会以 SeO 的形式释放出来，因此需要采用技术来捕获它。为捕获气态 SeO，制备了 CaO 颗粒（CPs）。研究了操作条件对氧化硒捕获性能的影响。CP 与 SeO 发生强烈反应，生成 CaSeO，在 700 °C 时的吸附容量高达 17.5 mol kg，吸附效率大于 99%。机械强度和热稳定性评估表明，这种材料适合实际应用。根据流速的不同，估算了处理 1 吨 SNF 时捕获 SeO 所需的氯化石蜡，从而有助于设计有效的 SeO 捕获系统，实现安全、可持续的核废料管理。
{"title":"Effective capture of gaseous Se during spent nuclear fuel recycling using calcium oxide pellets: Optimization, performance, and practical implications","authors":"Seok-Min Hong, Chang Hwa Lee, Jae-Hwan Yang, Namcheol Kim","doi":"10.1016/j.net.2024.08.021","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.021","url":null,"abstract":"The continuous utilization of nuclear energy has led to the accumulation of spent nuclear fuel (SNF) containing uranium, transuranium, and fission products (FPs). Reprocessing and pyrochemical methods have shown the potential for SNF reuse, thereby reducing its environmental impact. Voloxidation, a pivotal step in SNF recycling, involves thermal treatment in an oxidizing atmosphere to enhance the reactivity. During voloxidation, Se-79, which is a FP with a long half-life, is released as SeO under oxidizing conditions, necessitating technologies to capture it. CaO pellets (CPs) were prepared to capture gaseous SeO. The effects of operating conditions on SeO capture performance were investigated. The CP reacts strongly with SeO to form CaSeO, exhibiting a high adsorption capacity of 17.5 mol kg and >99 % efficiency at 700 °C. The mechanical strength and thermal stability assessments indicate suitability for practical applications. Depending on the flow rate, the CP required for SeO capture was estimated when processing 1 t of SNF, thereby contributing to the design of effective SeO capture systems for safe and sustainable nuclear waste management.","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":"142207311","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.2024.08.018
Soonwoo Han, Jae-Seon Lee
In this study, we proposed in-vessel two-channel control rod positioner models for small nuclear reactors and carried out performance tests to evaluate applicability of the models. Embedding control rod positioners in reactors reduces the volume of small reactors and minimizes the penetration parts of reactor. In this study, two models having two physically separated solenoids were developed for measuring the position of the control rod by using the inductance change of a solenoid. First, the principle of measuring the position of a ferromagnetic rod by using a solenoid was formulated, and the change in solenoid inductance with the rod position was calculated through finite element analysis. Based on the proposed models, test products were manufactured and tested on three items to confirm the feasibility of the proposed solenoid-based two-channel control rod position indicator.
{"title":"Development and experimental validation of conceptual models for solenoid-based in-vessel two-channel control rod position indicator","authors":"Soonwoo Han, Jae-Seon Lee","doi":"10.1016/j.net.2024.08.018","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.018","url":null,"abstract":"In this study, we proposed in-vessel two-channel control rod positioner models for small nuclear reactors and carried out performance tests to evaluate applicability of the models. Embedding control rod positioners in reactors reduces the volume of small reactors and minimizes the penetration parts of reactor. In this study, two models having two physically separated solenoids were developed for measuring the position of the control rod by using the inductance change of a solenoid. First, the principle of measuring the position of a ferromagnetic rod by using a solenoid was formulated, and the change in solenoid inductance with the rod position was calculated through finite element analysis. Based on the proposed models, test products were manufactured and tested on three items to confirm the feasibility of the proposed solenoid-based two-channel control rod position indicator.","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":"142226267","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.2024.08.022
A. Abdelghafar Galahom, Nassar Alnassar, Amr Ibrahim
This work investigates the possibility of getting rid of the accumulated plutonium around the world by mixing it with fertile materials and using it as a nuclear fuel for CANDU-6. Using plutonium isotopes with thorium as a nuclear fuel for CANDU-6 is a means of preventing the production of other Pu isotopes. MCNPX has been used to design a three dimensional model of the CANDU-6 bundle. Three fuel types including (U, rgPu)O, (Th, rgPu)O and (Th, wgPu)O have been examined as nuclear fuel in the designed model and their results were compared with UO as a standard fuel. The fuel burnup parameters such as k, fissile inventory ratio, plutonium concentration and minor actinides concentration have been analyzed for the suggested fuels. Some of the most related safety parameters such as effective delayed neutrons (β), moderator temperature coefficient, coolant temperature coefficient and Doppler constant have been studied. The excess thermal neutrons in the CANDU-6 maximized the benefit of using plutonium-based fuels, where a significant amount of plutonium has been burned during the fuel cycle. From the neutronic and safety point of view, thorium fuel mixed with reactor grade plutonium has proven to be the most promising candidate among the investigated fuels.
{"title":"Searching for incinerating the accumulated plutonium around the world by mixing it with thorium and using this mixture as a nuclear fuel in the CANDU-6","authors":"A. Abdelghafar Galahom, Nassar Alnassar, Amr Ibrahim","doi":"10.1016/j.net.2024.08.022","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.022","url":null,"abstract":"This work investigates the possibility of getting rid of the accumulated plutonium around the world by mixing it with fertile materials and using it as a nuclear fuel for CANDU-6. Using plutonium isotopes with thorium as a nuclear fuel for CANDU-6 is a means of preventing the production of other Pu isotopes. MCNPX has been used to design a three dimensional model of the CANDU-6 bundle. Three fuel types including (U, rgPu)O, (Th, rgPu)O and (Th, wgPu)O have been examined as nuclear fuel in the designed model and their results were compared with UO as a standard fuel. The fuel burnup parameters such as k, fissile inventory ratio, plutonium concentration and minor actinides concentration have been analyzed for the suggested fuels. Some of the most related safety parameters such as effective delayed neutrons (β), moderator temperature coefficient, coolant temperature coefficient and Doppler constant have been studied. The excess thermal neutrons in the CANDU-6 maximized the benefit of using plutonium-based fuels, where a significant amount of plutonium has been burned during the fuel cycle. From the neutronic and safety point of view, thorium fuel mixed with reactor grade plutonium has proven to be the most promising candidate among the investigated fuels.","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":"142207256","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 fluidelastic instability (FEI) in heat exchanger tubes has been of widespread concern due to its tendency to cause damage to the tubes. Generally, FEI in the transverse direction of the tube occurs earlier than in the streamwise direction, and the intrinsic frequency of the tube as well as the way of tube distribution have a great influence. The mechanisms involved in inducing FEI need to be further investigated. We set up an air-water two-phase flow water tunnel test system and adopt a normal triangular arrangement plate with a pitch-to-diameter ratio of 1.41 to conduct experiments. It was ensured that FEI could occur in the experimental flow range, by varying the intrinsic frequency of the flexible tube. The fluidelastic instability phenomenon was investigated in a single flexible tube array and a cluster of seven flexible tubes (the central cluster). Comparative analysis was conducted between the results of the two array configurations. The experiments involved concurrent streamwise and transverse directions, and an analysis of the pressure exerted on the flexible tubes. Additionally, the “transitional” state observed in flexible tubes under strongly coupled vibration in the central cluster was explored. The findings indicated that a cluster of seven flexible tubes intensified the vibration coupling between bundles, leading to a more complex flow field around the tube bundle perimeter, consequently exacerbating tube vibration. Furthermore, under the “transitional” state, enhanced stability was manifested. Additionally, instability in the streamwise direction was primarily controlled by the stiffness mechanism; a single flexible tube did not exhibit fluidelastic instability in the streamwise direction, while the central cluster did. This paper recommends an instability constant (K) value of 3.4 for the Connors formula for a normal triangular tube bundle configuration with the pitch-to-diameter ratio of 1.41, thereby providing empirical and theoretical support for the vibration analysis of tube bundles.
{"title":"Study of fluidelastic instability in the streamwise and transverse directions through tube array under two-phase flow conditions using pressure effects","authors":"Sijiu Qi, Wei Tan, Ke Zhang, Yuancen Wang, Wenjing Lin, Peize Han, Guorui Zhu","doi":"10.1016/j.net.2024.08.017","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.017","url":null,"abstract":"The fluidelastic instability (FEI) in heat exchanger tubes has been of widespread concern due to its tendency to cause damage to the tubes. Generally, FEI in the transverse direction of the tube occurs earlier than in the streamwise direction, and the intrinsic frequency of the tube as well as the way of tube distribution have a great influence. The mechanisms involved in inducing FEI need to be further investigated. We set up an air-water two-phase flow water tunnel test system and adopt a normal triangular arrangement plate with a pitch-to-diameter ratio of 1.41 to conduct experiments. It was ensured that FEI could occur in the experimental flow range, by varying the intrinsic frequency of the flexible tube. The fluidelastic instability phenomenon was investigated in a single flexible tube array and a cluster of seven flexible tubes (the central cluster). Comparative analysis was conducted between the results of the two array configurations. The experiments involved concurrent streamwise and transverse directions, and an analysis of the pressure exerted on the flexible tubes. Additionally, the “transitional” state observed in flexible tubes under strongly coupled vibration in the central cluster was explored. The findings indicated that a cluster of seven flexible tubes intensified the vibration coupling between bundles, leading to a more complex flow field around the tube bundle perimeter, consequently exacerbating tube vibration. Furthermore, under the “transitional” state, enhanced stability was manifested. Additionally, instability in the streamwise direction was primarily controlled by the stiffness mechanism; a single flexible tube did not exhibit fluidelastic instability in the streamwise direction, while the central cluster did. This paper recommends an instability constant (K) value of 3.4 for the Connors formula for a normal triangular tube bundle configuration with the pitch-to-diameter ratio of 1.41, thereby providing empirical and theoretical support for the vibration analysis of tube bundles.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207263","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 : 2024-08-12DOI: 10.1016/j.net.2024.08.019
Jacob G. Fantidis, Athanasia Κ. Thomoglou, Maristella Ε. Voutetaki, Bassam Tayeh, George Nikolaou
The evaluation of non-destructive neutron radiography (NR) for examining the internal composition of various structural materials, has been the focus of extensive research. This manuscript uses non-destructive testing to generate three-dimensional radiographs of three different brick structural materials: glass block, magnesia-chrome, and lead to evaluate their capability to withstand fast neutrons and gammas emitted from a source. When neutrons with thermal or epithermal spectrum are required, the optimum combination for an accelerator was simulated using a 2.8 MeV proton beam on a lithium target. The presented facility tested both thermal and fast neutron radiography. This study examined various aperture diameters and collimator lengths. It found that implementing a special fast neutron filter significantly increased the thermal neutron content (TNC) with minimal impact on the thermal neutron flux. For fast neutron radiography, the study evaluated parameters such as geometric unsharpness, fast neutron flux, and the percentage of the uncollided fast neutron reaching the object. Both neutrons and photons from the source were used to inspect faults in a glass brick.
{"title":"Bricks non-destructive simulation testing method utilizing neutron radiography facility based on a 7Li(p,n)7Be reaction","authors":"Jacob G. Fantidis, Athanasia Κ. Thomoglou, Maristella Ε. Voutetaki, Bassam Tayeh, George Nikolaou","doi":"10.1016/j.net.2024.08.019","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.019","url":null,"abstract":"The evaluation of non-destructive neutron radiography (NR) for examining the internal composition of various structural materials, has been the focus of extensive research. This manuscript uses non-destructive testing to generate three-dimensional radiographs of three different brick structural materials: glass block, magnesia-chrome, and lead to evaluate their capability to withstand fast neutrons and gammas emitted from a source. When neutrons with thermal or epithermal spectrum are required, the optimum combination for an accelerator was simulated using a 2.8 MeV proton beam on a lithium target. The presented facility tested both thermal and fast neutron radiography. This study examined various aperture diameters and collimator lengths. It found that implementing a special fast neutron filter significantly increased the thermal neutron content (TNC) with minimal impact on the thermal neutron flux. For fast neutron radiography, the study evaluated parameters such as geometric unsharpness, fast neutron flux, and the percentage of the uncollided fast neutron reaching the object. Both neutrons and photons from the source were used to inspect faults in a glass brick.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207262","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 : 2024-08-10DOI: 10.1016/j.net.2024.08.016
Yuanjie Fang, Minrui Fei, Hong Qian
Reactor power level control is an effective way to achieve load tracking of Pressurized Water Reactor (PWR) in a nuclear power station. A novel Nonlinear Generalized Predictive Control with Extended Kalman Filter (NGPC + EKF) is proposed to solve the problem that discrete predictive model mismatch in noisy environment. In this paper, an NGPC controller is developed to realize the reactor load tracking, and an EKF is used to estimate reactor states and suppress noise. Finally, the control methods of PID, MPC, NGPC and NGPC + EKF are compared by two simulation experiments, load tracking experiment and step response experiment. The load tracking experiment results show that NGPC + EKF method obtains better noise suppression ability and tracking effect. In the step response experiment, the proposed NGPC + EKF scheme is also proved to have better step response performance than others.
{"title":"Pressurized Water reactor power level control: A nonlinear generalized predictive control with extended Kalman filter method","authors":"Yuanjie Fang, Minrui Fei, Hong Qian","doi":"10.1016/j.net.2024.08.016","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.016","url":null,"abstract":"Reactor power level control is an effective way to achieve load tracking of Pressurized Water Reactor (PWR) in a nuclear power station. A novel Nonlinear Generalized Predictive Control with Extended Kalman Filter (NGPC + EKF) is proposed to solve the problem that discrete predictive model mismatch in noisy environment. In this paper, an NGPC controller is developed to realize the reactor load tracking, and an EKF is used to estimate reactor states and suppress noise. Finally, the control methods of PID, MPC, NGPC and NGPC + EKF are compared by two simulation experiments, load tracking experiment and step response experiment. The load tracking experiment results show that NGPC + EKF method obtains better noise suppression ability and tracking effect. In the step response experiment, the proposed NGPC + EKF scheme is also proved to have better step response performance than others.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207264","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 : 2024-08-08DOI: 10.1016/j.net.2024.08.014
Karyoung Choi, Minseok Kim, Kibeom Son, Gyunyoung Heo
Deep geological disposal, which is a permanent method that isolates a storage facility in rocks 200 to 1000 m deep underground, plays a role in safely disposing spent nuclear fuel to prevent excessive radioactive species from leaking out and its safety should be primarily proved. Risk for various radionuclide leakage scenarios should be calculated to be used as a safety indicator. One of the scenarios that significantly affects the safety of repository is the occurrence of external events such as an earthquake scenario. Several occurrences of such external disasters are expected over a long period of time which the safety functions of the deep disposal site must be maintained. Rather than performing a conservative single event evaluation, we expected that performing a more realistic evaluation, such as considering the number of events, is preferrable for design and operation optimization, particularly in an early project phase. This paper suggests a need for assessing multi-event scenarios and the methodology for simulation of several external disasters using earthquakes as an example. The methodology and algorithm of simulating multiple earthquakes and assessing risk distribution under those events at repository site is introduced in GoldSim software, and its results are expected to be used at simulating other event scenarios.
{"title":"Methodology for risk assessment of multi-event scenarios on radioactive waste repository","authors":"Karyoung Choi, Minseok Kim, Kibeom Son, Gyunyoung Heo","doi":"10.1016/j.net.2024.08.014","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.014","url":null,"abstract":"Deep geological disposal, which is a permanent method that isolates a storage facility in rocks 200 to 1000 m deep underground, plays a role in safely disposing spent nuclear fuel to prevent excessive radioactive species from leaking out and its safety should be primarily proved. Risk for various radionuclide leakage scenarios should be calculated to be used as a safety indicator. One of the scenarios that significantly affects the safety of repository is the occurrence of external events such as an earthquake scenario. Several occurrences of such external disasters are expected over a long period of time which the safety functions of the deep disposal site must be maintained. Rather than performing a conservative single event evaluation, we expected that performing a more realistic evaluation, such as considering the number of events, is preferrable for design and operation optimization, particularly in an early project phase. This paper suggests a need for assessing multi-event scenarios and the methodology for simulation of several external disasters using earthquakes as an example. The methodology and algorithm of simulating multiple earthquakes and assessing risk distribution under those events at repository site is introduced in GoldSim software, and its results are expected to be used at simulating other event scenarios.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207265","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 : 2024-08-08DOI: 10.1016/j.net.2024.08.012
Junhyuk Jang, Minsoo Lee, Gha-Young Kim, Seok Yoon
Copper oxidation at low temperatures below 140 °C and its effects on corrosive behavior in aerobic groundwater are investigated to estimate the intactness of canisters at early stages of disposal. The Cu coupon surface is covered by fine particles that form thin oxide layers after 30 d of oxidation; a thin CuO layer of thickness <100 nm is formed after oxidation at 40 °C; after oxidation at 140 °C, the CuO surface changes to a CuO layer of thickness <500 nm. The thickness of the Cu surface oxidized at 90 °C is between those of the surfaces oxidized at 40 and 140 °C. All Cu coupons exhibit similar current densities ranging from 0.77 to 1.87 μA cm, although the corrosion potential of the Cu coupon layered with CuO is higher than that of the others. Long-term oxidation tests for 406 d reveal no significant changes in the Cu surface at temperatures below 90 °C, indicating no significant change in the electrochemical behavior. The results of this study suggest that the storage of canisters at temperatures below 90 °C has no significant effect on the degradation of canister performance in long-term disposal.
研究了铜在低于 140 °C 的低温下的氧化及其对好氧地下水中腐蚀行为的影响，以估计早期处置阶段滤毒罐的完好性。铜券表面被细颗粒覆盖，氧化 30 d 后形成薄氧化层；40 °C 氧化后形成厚度小于 100 nm 的薄 CuO 层；140 °C 氧化后，CuO 表面变为厚度小于 500 nm 的 CuO 层。在 90 °C 下氧化的铜表面厚度介于在 40 °C 和 140 °C 下氧化的表面厚度之间。所有的铜试样都显示出类似的电流密度，范围在 0.77 到 1.87 μA cm 之间，但层状 CuO 铜试样的腐蚀电位高于其他试样。406 d 的长期氧化测试显示，在低于 90 °C 的温度下，铜表面没有发生明显变化，这表明电化学行为没有发生重大变化。这项研究的结果表明，在低于 90 °C 的温度下储存滤毒罐对滤毒罐在长期处置过程中的性能退化没有明显影响。
{"title":"Corrosive behavior of copper canisters under air and aerobic groundwater at early stages of deep geological disposal","authors":"Junhyuk Jang, Minsoo Lee, Gha-Young Kim, Seok Yoon","doi":"10.1016/j.net.2024.08.012","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.012","url":null,"abstract":"Copper oxidation at low temperatures below 140 °C and its effects on corrosive behavior in aerobic groundwater are investigated to estimate the intactness of canisters at early stages of disposal. The Cu coupon surface is covered by fine particles that form thin oxide layers after 30 d of oxidation; a thin CuO layer of thickness <100 nm is formed after oxidation at 40 °C; after oxidation at 140 °C, the CuO surface changes to a CuO layer of thickness <500 nm. The thickness of the Cu surface oxidized at 90 °C is between those of the surfaces oxidized at 40 and 140 °C. All Cu coupons exhibit similar current densities ranging from 0.77 to 1.87 μA cm, although the corrosion potential of the Cu coupon layered with CuO is higher than that of the others. Long-term oxidation tests for 406 d reveal no significant changes in the Cu surface at temperatures below 90 °C, indicating no significant change in the electrochemical behavior. The results of this study suggest that the storage of canisters at temperatures below 90 °C has no significant effect on the degradation of canister performance in long-term disposal.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207267","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 : 2024-08-08DOI: 10.1016/j.net.2024.08.015
M.I. Sayyed, K.A. Mahmoud, Taha A. Hanafy
This work presents a study of the effect of replacing lead dioxide and gadolinium (III) oxide with boron trioxide on the physical, mechanical, and radiation shielding properties for the BO-NaO-ZnO-PbO-GdO glass systems. The Archimedes method confirms that the increase in the PbO+GdO concentration within the fabricated glass system in the range from 16 to 22 mol.% increases the fabricated glass samples' density from 4.052 to 4.408 g/cm. Additionally, the Makishima-Mackenzie model was utilized to investigate the influence of PbO+GdO on the mechanical properties of the investigated glass samples. The increase in the substituting of PbO+GdO decreases the fabricated glass samples' mechanical properties and micro-hardness. Furthermore, the Monte Carlo simulation method was applied for the estimation of the impact of PbO+GdO concentration on the fabricated samples' radiation shielding parameters. The increase in the concentration of PbO+GdO with range of (16, 18, 20 and 22) leads to increase the linear attenuation coefficient (LAC) to 8.014–11.517 cm at 0.06 MeV, 0.381–0.423 cm at 0.6 MeV, 0.133–0.149 cm at 5 MeV, and 0.132–0.154 cm at 15 MeV with the same order, respectively. Therefore, the introduction of PbO+GdO concentration enhances the fabricated glass samples' radiation shielding properties to be suitable for γ-ray shielding applications.
{"title":"A new protective glass material against gamma ray: Thorough analysis to determine the impact of adding gadolinium (III) oxide","authors":"M.I. Sayyed, K.A. Mahmoud, Taha A. Hanafy","doi":"10.1016/j.net.2024.08.015","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.015","url":null,"abstract":"This work presents a study of the effect of replacing lead dioxide and gadolinium (III) oxide with boron trioxide on the physical, mechanical, and radiation shielding properties for the BO-NaO-ZnO-PbO-GdO glass systems. The Archimedes method confirms that the increase in the PbO+GdO concentration within the fabricated glass system in the range from 16 to 22 mol.% increases the fabricated glass samples' density from 4.052 to 4.408 g/cm. Additionally, the Makishima-Mackenzie model was utilized to investigate the influence of PbO+GdO on the mechanical properties of the investigated glass samples. The increase in the substituting of PbO+GdO decreases the fabricated glass samples' mechanical properties and micro-hardness. Furthermore, the Monte Carlo simulation method was applied for the estimation of the impact of PbO+GdO concentration on the fabricated samples' radiation shielding parameters. The increase in the concentration of PbO+GdO with range of (16, 18, 20 and 22) leads to increase the linear attenuation coefficient (LAC) to 8.014–11.517 cm at 0.06 MeV, 0.381–0.423 cm at 0.6 MeV, 0.133–0.149 cm at 5 MeV, and 0.132–0.154 cm at 15 MeV with the same order, respectively. Therefore, the introduction of PbO+GdO concentration enhances the fabricated glass samples' radiation shielding properties to be suitable for γ-ray shielding applications.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207266","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 : 2024-08-06DOI: 10.1016/j.net.2024.08.005
Andrew K. Gillespie, Cuikun Lin, Django Jones, Sandeep Puri, R.V. Duncan
Materials used to study nuclear fusion can retain atmospheric helium unless pretreated before an experiment. Understanding helium outgassing is important for accurate diagnostics in experiments surrounding nuclear fusion. The presence of helium is often cited as the primary evidence that a nuclear reaction has occurred, so it is imperative that known sources of helium are mitigated prior to proceeding with novel nuclear experiments. It is also necessary to ensure hermeticity when transferring gas aliquots from an experiment to a mass spectrometer. In this article, we present studies of helium leak rates in systems used in novel nuclear experiments. We also present studies of helium retention in materials subjected to various heating profiles and atmospheric concentrations. Without pretreatment, 12-inch lengths of both 3/8” diameter tubes and 1/2″ diameter stainless-steel 316 tubing yielded an average areal outgassing amount of 0.64 pmol/cm. If pretreatment is impractical, then the results may be scaled based on the tubing length necessary for constructing custom experimental equipment. It also may reabsorb He from the atmosphere in time. These studies also demonstrate that it is necessary to pretreat most materials prior to performing experiments where the presence of He is being used as an indicator for novel nuclear reactions.
{"title":"Exploring helium retention from technical materials: Development and investigation","authors":"Andrew K. Gillespie, Cuikun Lin, Django Jones, Sandeep Puri, R.V. Duncan","doi":"10.1016/j.net.2024.08.005","DOIUrl":"https://doi.org/10.1016/j.net.2024.08.005","url":null,"abstract":"Materials used to study nuclear fusion can retain atmospheric helium unless pretreated before an experiment. Understanding helium outgassing is important for accurate diagnostics in experiments surrounding nuclear fusion. The presence of helium is often cited as the primary evidence that a nuclear reaction has occurred, so it is imperative that known sources of helium are mitigated prior to proceeding with novel nuclear experiments. It is also necessary to ensure hermeticity when transferring gas aliquots from an experiment to a mass spectrometer. In this article, we present studies of helium leak rates in systems used in novel nuclear experiments. We also present studies of helium retention in materials subjected to various heating profiles and atmospheric concentrations. Without pretreatment, 12-inch lengths of both 3/8” diameter tubes and 1/2″ diameter stainless-steel 316 tubing yielded an average areal outgassing amount of 0.64 pmol/cm. If pretreatment is impractical, then the results may be scaled based on the tubing length necessary for constructing custom experimental equipment. It also may reabsorb He from the atmosphere in time. These studies also demonstrate that it is necessary to pretreat most materials prior to performing experiments where the presence of He is being used as an indicator for novel nuclear reactions.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207269","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：