Haoxiang Li, Weizhen Zheng, B. Du, Huaqiang Yin, Zhihao Hong, Long Wang, Xuedong He, Tengyu Ma, Xingtuan Yang
In high temperature gas cooled reactor (HTGR), there is a small amount of helium in the primary coolant (ppm level) impure impurities, which will corrode the alloy materials of high temperature reactor and affect the performance of equipment in high temperature environment. The coating preparation technology on the alloy surface can effectively protect the alloy matrix, greatly reduce the corrosion rate of alloy, and improve the reliability and safety of equipment. In this paper, a Cr2O3/α-Al2O3 multilayer barrier coating prepared by RF magnetron sputtering was used to coat Incoloy 800H alloy, and the corrosion behavior of Incoloy 800H alloy with and without coating under selected high-temperature impure helium was investigated. After the experiment, the corrosion results were analyzed by weighing, scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDS). The results showed that Cr2O3/ α-Al2O3 barrier coating partially fell off after high temperature corrosion; The internal oxidation phenomenon of the alloy was not obvious, and the coating can inhibit the oxidation and carburization of the alloy; The mass of the alloy increased after corrosion, and the mass gain of the coated alloy was lower than that of the uncoated alloy.
{"title":"Effect of a Cr2O3/A-Al2O3 Coating on the Corrosion Behavior of Incoloy 800H Alloy in High Temperature Impure Helium","authors":"Haoxiang Li, Weizhen Zheng, B. Du, Huaqiang Yin, Zhihao Hong, Long Wang, Xuedong He, Tengyu Ma, Xingtuan Yang","doi":"10.1115/icone29-90536","DOIUrl":"https://doi.org/10.1115/icone29-90536","url":null,"abstract":"\u0000 In high temperature gas cooled reactor (HTGR), there is a small amount of helium in the primary coolant (ppm level) impure impurities, which will corrode the alloy materials of high temperature reactor and affect the performance of equipment in high temperature environment. The coating preparation technology on the alloy surface can effectively protect the alloy matrix, greatly reduce the corrosion rate of alloy, and improve the reliability and safety of equipment. In this paper, a Cr2O3/α-Al2O3 multilayer barrier coating prepared by RF magnetron sputtering was used to coat Incoloy 800H alloy, and the corrosion behavior of Incoloy 800H alloy with and without coating under selected high-temperature impure helium was investigated. After the experiment, the corrosion results were analyzed by weighing, scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDS). The results showed that Cr2O3/ α-Al2O3 barrier coating partially fell off after high temperature corrosion; The internal oxidation phenomenon of the alloy was not obvious, and the coating can inhibit the oxidation and carburization of the alloy; The mass of the alloy increased after corrosion, and the mass gain of the coated alloy was lower than that of the uncoated alloy.","PeriodicalId":36762,"journal":{"name":"Journal of Nuclear Fuel Cycle and Waste Technology","volume":"13 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83632595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Glass solidification is a favorable treatment method for high level liquid waste (HLLW) from spent fuel reprocessing in industrial application, and the presence of palladium (Pd) in HLLW may seriously affect the glass solidification process. Ferrocyanide with a perovskite-like face-centered cubic structure has strong adsorption affinity towards Pd. In this study, silica-based composite KMnFC/SiO2 was prepared by pore crystallization of potassium manganese ferrocyanide (KMnFC) into porous SiO2. A series of characterization of the synthesized adsorbent were carried out such as XRD, TG-DTA, and SEM-EDS. It was verified that the adsorbent was successfully prepared and it has good Microscopic structure along with element distribution. A series of adsorption experiments were carried out. The adsorption of Pd is not easily affected by the concentration of nitric acid, which shows good acid resistance. Through the adsorption isotherm and adsorption kinetic curve, it is proved that the adsorption process of Pd by KMnFC/SiO2 is chemical monolayer adsorption. The adsorbent has strong adsorption selectivity for Pd in multi-ionic solution. Under the condition of complete adsorption of Pd, the adsorption rate of the adsorbent for other elements except Ru is less than 20%.
{"title":"Study on Separation of Palladium From High Level Liquid Waste by Potassium Manganese Ferrocyanide","authors":"Tian-Jiao Qi, Hongji Sang, Cong Mao, Yueying Wen, Jipu Hu, Yan Wu","doi":"10.1115/icone29-92971","DOIUrl":"https://doi.org/10.1115/icone29-92971","url":null,"abstract":"\u0000 Glass solidification is a favorable treatment method for high level liquid waste (HLLW) from spent fuel reprocessing in industrial application, and the presence of palladium (Pd) in HLLW may seriously affect the glass solidification process. Ferrocyanide with a perovskite-like face-centered cubic structure has strong adsorption affinity towards Pd. In this study, silica-based composite KMnFC/SiO2 was prepared by pore crystallization of potassium manganese ferrocyanide (KMnFC) into porous SiO2. A series of characterization of the synthesized adsorbent were carried out such as XRD, TG-DTA, and SEM-EDS. It was verified that the adsorbent was successfully prepared and it has good Microscopic structure along with element distribution.\u0000 A series of adsorption experiments were carried out. The adsorption of Pd is not easily affected by the concentration of nitric acid, which shows good acid resistance. Through the adsorption isotherm and adsorption kinetic curve, it is proved that the adsorption process of Pd by KMnFC/SiO2 is chemical monolayer adsorption. The adsorbent has strong adsorption selectivity for Pd in multi-ionic solution. Under the condition of complete adsorption of Pd, the adsorption rate of the adsorbent for other elements except Ru is less than 20%.","PeriodicalId":36762,"journal":{"name":"Journal of Nuclear Fuel Cycle and Waste Technology","volume":"16 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83807286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Very-high-temperature gas-cooled reactors (VHTR) are being developed to provide higher thermal efficiency and high-temperature process heat. Zirconium carbide (ZrC) has been proposed as a potential coating material for TRistructural-ISOtropic (TRISO) coated fuel particles because of its excellent resistance to fission products corrosion, good thermal stability and higher mechanical strength under elevated temperatures. The integrity and performance of the ZrC coating of the TRISO particles are very important as it provides the main barrier for fission product release. Therefore, the microstructure and property evolution of ZrC coating deserve to be investigated. Fluidized-bed chemical vapor deposition (FB-CVD) has been conducted to fabricate the ZrC coating in a ZrCl4−C3H6-Ar-H2 system. The stoichiometry of ZrC was changed by controlling the feeding rate of ZrCl4 and the flow rate of C3H6. The ZrC coatings were annealed from 1700 °C to 2200 °C to study the possible changes in microstructures and temperature-dependent performances. The effect of stoichiometries on ZrC coating was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy (Raman), and nanoindenter. Results showed that free carbon prevents grain growth under high-temperature annealing, and it reacts with ZrC1-x at higher temperatures to form pure phase ZrC. In addition, the microstructure evolution mechanism of ZrC at high temperatures was proposed.
{"title":"Effects of Stoichiometry and High-Temperature Annealing on Zirconium Carbide Coating Layer in TRISO Particles","authors":"Xinyu Cheng, Rongzheng Liu, Bing Liu, Xueru Yang, Malin Liu, J. Chang, You-lin Shao","doi":"10.1115/icone29-92858","DOIUrl":"https://doi.org/10.1115/icone29-92858","url":null,"abstract":"\u0000 Very-high-temperature gas-cooled reactors (VHTR) are being developed to provide higher thermal efficiency and high-temperature process heat. Zirconium carbide (ZrC) has been proposed as a potential coating material for TRistructural-ISOtropic (TRISO) coated fuel particles because of its excellent resistance to fission products corrosion, good thermal stability and higher mechanical strength under elevated temperatures. The integrity and performance of the ZrC coating of the TRISO particles are very important as it provides the main barrier for fission product release. Therefore, the microstructure and property evolution of ZrC coating deserve to be investigated. Fluidized-bed chemical vapor deposition (FB-CVD) has been conducted to fabricate the ZrC coating in a ZrCl4−C3H6-Ar-H2 system. The stoichiometry of ZrC was changed by controlling the feeding rate of ZrCl4 and the flow rate of C3H6. The ZrC coatings were annealed from 1700 °C to 2200 °C to study the possible changes in microstructures and temperature-dependent performances. The effect of stoichiometries on ZrC coating was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy (Raman), and nanoindenter. Results showed that free carbon prevents grain growth under high-temperature annealing, and it reacts with ZrC1-x at higher temperatures to form pure phase ZrC. In addition, the microstructure evolution mechanism of ZrC at high temperatures was proposed.","PeriodicalId":36762,"journal":{"name":"Journal of Nuclear Fuel Cycle and Waste Technology","volume":"35 2 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83006706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gui Zhong, Zhang Hui, Wang Wei, Yuan Yueyan, Liu Chao, Li Xiaoqing
With the rapid growth of China’s nuclear power scale, in order to meet the future demand for spent fuel transport, relying on a single road transport mode is far from meeting the transport demand. It is necessary to build a spent fuel multimodal transport system to carry out large-scale spent fuel transport. As a special means of transport for sea transport in spent fuel multimodal transport, China’s first spent fuel transport ship is completely independently designed by China, has passed the empty ship trial voyage, and has also achieved good practice in actual transport. Based on the design requirements of domestic and international laws and regulations for the spent fuel transport ship, and combined with the actual situation of the wharf of domestic nuclear power plant, this paper interprets and analyzes the design ideas of the ship type size, loading layout scheme and safety system of the first spent fuel transport ship in China, in order to provide technical reference for the design and improvement of the spent fuel transport ship in the future.
{"title":"Interpretation and Analysis of Design Idea of the Spent Fuel Transport Ship","authors":"Gui Zhong, Zhang Hui, Wang Wei, Yuan Yueyan, Liu Chao, Li Xiaoqing","doi":"10.1115/icone29-92809","DOIUrl":"https://doi.org/10.1115/icone29-92809","url":null,"abstract":"\u0000 With the rapid growth of China’s nuclear power scale, in order to meet the future demand for spent fuel transport, relying on a single road transport mode is far from meeting the transport demand. It is necessary to build a spent fuel multimodal transport system to carry out large-scale spent fuel transport. As a special means of transport for sea transport in spent fuel multimodal transport, China’s first spent fuel transport ship is completely independently designed by China, has passed the empty ship trial voyage, and has also achieved good practice in actual transport. Based on the design requirements of domestic and international laws and regulations for the spent fuel transport ship, and combined with the actual situation of the wharf of domestic nuclear power plant, this paper interprets and analyzes the design ideas of the ship type size, loading layout scheme and safety system of the first spent fuel transport ship in China, in order to provide technical reference for the design and improvement of the spent fuel transport ship in the future.","PeriodicalId":36762,"journal":{"name":"Journal of Nuclear Fuel Cycle and Waste Technology","volume":"24 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79124455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The build-up of deposits (Crud) on fuel cladding can cause several issues for PWRs. The crud becomes activated and is transported to other locations in the RCS increasing radiation fields, it can collect boron causing power shifts (CIPS, Crud Induced Power Shifts) and if thick enough localized corrosion will be increased (CILC, Crud Induced Localized Corrosion). The application of a chromium coating to zirconium alloy cladding is being pursued to improve the corrosion performance of the cladding both during normal operation and in the event of accident conditions producing high cladding temperatures. The change will also influence the crud affinity of the cladding. The deposition of corrosion products from the ex-core portions of the plant will be altered. Also, corrosion of the cladding itself contributes to the crud burden in a PWR, and this factor will undoubtedly change with the application of a chromium coating. Changes in the surface texture produced by the coating will also influence crud deposition by changing boiling nucleation and thermal hydraulic factors. This paper discusses how a change to chromium coated fuel cladding will likely affect crud deposition and will give the results of crud deposition testing of chromium coated cladding in the WALT loop.
{"title":"Potential Crud Related Margin Gains With Chromium Coated Zirconium Cladding","authors":"W. Byers, Guoqiang Wang","doi":"10.1115/icone29-94477","DOIUrl":"https://doi.org/10.1115/icone29-94477","url":null,"abstract":"\u0000 The build-up of deposits (Crud) on fuel cladding can cause several issues for PWRs. The crud becomes activated and is transported to other locations in the RCS increasing radiation fields, it can collect boron causing power shifts (CIPS, Crud Induced Power Shifts) and if thick enough localized corrosion will be increased (CILC, Crud Induced Localized Corrosion). The application of a chromium coating to zirconium alloy cladding is being pursued to improve the corrosion performance of the cladding both during normal operation and in the event of accident conditions producing high cladding temperatures. The change will also influence the crud affinity of the cladding. The deposition of corrosion products from the ex-core portions of the plant will be altered. Also, corrosion of the cladding itself contributes to the crud burden in a PWR, and this factor will undoubtedly change with the application of a chromium coating. Changes in the surface texture produced by the coating will also influence crud deposition by changing boiling nucleation and thermal hydraulic factors.\u0000 This paper discusses how a change to chromium coated fuel cladding will likely affect crud deposition and will give the results of crud deposition testing of chromium coated cladding in the WALT loop.","PeriodicalId":36762,"journal":{"name":"Journal of Nuclear Fuel Cycle and Waste Technology","volume":"10 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81263354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A dual-phase microstructure with 5–12% δ-ferrite is needed to prevent hot cracking of stainless steel weld metal. However, the δ-ferrite also makes it susceptible to long-term thermal aging embrittlement. Recent studies revealed that the stress corrosion cracking (SCC) susceptibility might either be reduced or increased by the δ-ferrite, depending on the embrittlement degree of the ferrite during the operation. One possible explanation was that the harder δ-ferrite inhibited the crack growth by changing the cracking direction and creating a highly branched crack path. To further reveal the mechanism of δ-ferrite effect on SCC behavior of those materials in high temperature water, a finite element investigation for the distribution of crack-tip stress and plastic strain field with and without δ-ferrite under a constant load was conducted. The result shows that the crack tip stress and plastic strain decrease when the crack encounters the δ-ferrite, indicating a lower cracking susceptibility, and the enhancement of δ-ferrite hardness can further reduce the crack-tip plastic strain. the severe stress and strain states occur along the ferrite edge, this indicates that the cracks are more tend to initiate and develop along the interface of δ-ferrite and austenite matrix.
{"title":"Numerical Study of the Effect of δ-Ferrite on Crack-Tip Mechanical Field","authors":"Yule Wu, Le-fu Zhang","doi":"10.1115/icone29-92656","DOIUrl":"https://doi.org/10.1115/icone29-92656","url":null,"abstract":"\u0000 A dual-phase microstructure with 5–12% δ-ferrite is needed to prevent hot cracking of stainless steel weld metal. However, the δ-ferrite also makes it susceptible to long-term thermal aging embrittlement. Recent studies revealed that the stress corrosion cracking (SCC) susceptibility might either be reduced or increased by the δ-ferrite, depending on the embrittlement degree of the ferrite during the operation. One possible explanation was that the harder δ-ferrite inhibited the crack growth by changing the cracking direction and creating a highly branched crack path. To further reveal the mechanism of δ-ferrite effect on SCC behavior of those materials in high temperature water, a finite element investigation for the distribution of crack-tip stress and plastic strain field with and without δ-ferrite under a constant load was conducted. The result shows that the crack tip stress and plastic strain decrease when the crack encounters the δ-ferrite, indicating a lower cracking susceptibility, and the enhancement of δ-ferrite hardness can further reduce the crack-tip plastic strain. the severe stress and strain states occur along the ferrite edge, this indicates that the cracks are more tend to initiate and develop along the interface of δ-ferrite and austenite matrix.","PeriodicalId":36762,"journal":{"name":"Journal of Nuclear Fuel Cycle and Waste Technology","volume":"43 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81284545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Q. Y. Lv, Libin Zhang, Minli Chen, Changyuan Gao, Yang Xu, Liu-tao Chen, J. Tan
This paper conducts in-depth research on zirconium alloys by combining results of out-of-pile corrosion and creep performance with microstructual and micro-chemical analysis using state-of-the-art (S)TEM, EDX and EBSD. The mechanism of different heat treatment processes on the macroscopic properties of zirconium alloys is explained from the microscopic level. By comparing various Zr-Sn-Nb alloys with different intermediate temperatures, it is discovered that creep resistance becomes better and the corrosion resistance becomes worse. It is found that average grain size increases gradually with increasing intermediate temperature, creep deformation is related with grain boundary slip, so the smaller grain size, the faster creep rate. In alloys with Nb content less than its solid solution limit in zirconium, when increasing the intermediate annealing temperature, there are fewer Nb-rich Zr-Fe-Cr-Nb second phase particles (SPPs) but more Cr-rich Zr-Fe-Cr-Nb SPPs, so the amount of Nb in solid solution in the matrix increases, which lead to better creep resistance due to solid solution strengthening and lower diffusion coefficient, however, with higher Nb solid solution content, there is more tetragonal to monoclinic oxide phase transition, which causes more cracking in the oxide and increases the corrosion rate.
{"title":"Microstructual and Micro-Chemical Analysis of Zr Cladding Alloys on Corrosion and Creep Properties","authors":"Q. Y. Lv, Libin Zhang, Minli Chen, Changyuan Gao, Yang Xu, Liu-tao Chen, J. Tan","doi":"10.1115/icone29-93770","DOIUrl":"https://doi.org/10.1115/icone29-93770","url":null,"abstract":"\u0000 This paper conducts in-depth research on zirconium alloys by combining results of out-of-pile corrosion and creep performance with microstructual and micro-chemical analysis using state-of-the-art (S)TEM, EDX and EBSD. The mechanism of different heat treatment processes on the macroscopic properties of zirconium alloys is explained from the microscopic level.\u0000 By comparing various Zr-Sn-Nb alloys with different intermediate temperatures, it is discovered that creep resistance becomes better and the corrosion resistance becomes worse. It is found that average grain size increases gradually with increasing intermediate temperature, creep deformation is related with grain boundary slip, so the smaller grain size, the faster creep rate. In alloys with Nb content less than its solid solution limit in zirconium, when increasing the intermediate annealing temperature, there are fewer Nb-rich Zr-Fe-Cr-Nb second phase particles (SPPs) but more Cr-rich Zr-Fe-Cr-Nb SPPs, so the amount of Nb in solid solution in the matrix increases, which lead to better creep resistance due to solid solution strengthening and lower diffusion coefficient, however, with higher Nb solid solution content, there is more tetragonal to monoclinic oxide phase transition, which causes more cracking in the oxide and increases the corrosion rate.","PeriodicalId":36762,"journal":{"name":"Journal of Nuclear Fuel Cycle and Waste Technology","volume":"7 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90134430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dongqing Tian, Li Shi, Libin Sun, Keya Shen, Kun Xu
Dynamic tensile strength is an important parameter in the design of graphite components for High Temperature Gas-Cooled Reactors (HTGR) to evaluate the integrity of core support structures. The Digital Image Correlation and Split Hopkinson Pressure Bar (DIC-SHPB) test system was used to perform the disc compression tests according to ASTM D8289-20 to study the dynamic splitting tensile strengths of graphites with different grain sizes. The fracture process was captured by a high-speed camera and the tensile strain was computed by DIC. The results show that the SHPB test method is capable of performing the disc compression tests of graphite. The dynamic tensile stress-strain curve of graphite underwent four stages: compression stage, near-elastic stage, crack development stage and crack non-stable extension stage. When the strain rate is in the range of 330 s−1 to 630 s−1, the dynamic tensile strength of graphite increases with increasing strain rate. The dynamic increase factor (DIF) of fine-grained graphite ranged from 1.05 to 1.2, while that of coarse-grained graphite was about 1.2 to 1.6. There is a large dispersion in the dynamic tensile strength of graphite when the strain rate is increased. It was found that the tensile strength of graphite improved considerably with increasing strain rate, while the fracture strain decreased slightly.
动态抗拉强度是高温气冷堆(HTGR)石墨构件设计中评价堆芯支撑结构完整性的重要参数。采用Digital Image Correlation and Split Hopkinson Pressure Bar (DIC-SHPB)测试系统，按照ASTM D8289-20的要求，进行圆盘压缩试验，研究不同晶粒尺寸石墨的动态劈裂拉伸强度。用高速摄像机捕捉断裂过程，用DIC计算拉伸应变。结果表明，SHPB试验方法能够进行石墨的圆盘压缩试验。石墨的动态拉伸应力-应变曲线经历了压缩阶段、近弹性阶段、裂纹发展阶段和裂纹非稳定扩展阶段四个阶段。当应变速率为330 s−1 ~ 630 s−1时，石墨的动态抗拉强度随应变速率的增大而增大。细粒石墨的动态增长因子(DIF)在1.05 ~ 1.2之间，粗粒石墨的动态增长因子在1.2 ~ 1.6之间。随着应变速率的增大，石墨的动态抗拉强度有较大的分散。结果表明，随着应变速率的增加，石墨的抗拉强度显著提高，而断裂应变略有下降。
{"title":"Experimental Study on Dynamic Tensile Strength of Graphite","authors":"Dongqing Tian, Li Shi, Libin Sun, Keya Shen, Kun Xu","doi":"10.1115/icone29-90670","DOIUrl":"https://doi.org/10.1115/icone29-90670","url":null,"abstract":"\u0000 Dynamic tensile strength is an important parameter in the design of graphite components for High Temperature Gas-Cooled Reactors (HTGR) to evaluate the integrity of core support structures. The Digital Image Correlation and Split Hopkinson Pressure Bar (DIC-SHPB) test system was used to perform the disc compression tests according to ASTM D8289-20 to study the dynamic splitting tensile strengths of graphites with different grain sizes. The fracture process was captured by a high-speed camera and the tensile strain was computed by DIC. The results show that the SHPB test method is capable of performing the disc compression tests of graphite. The dynamic tensile stress-strain curve of graphite underwent four stages: compression stage, near-elastic stage, crack development stage and crack non-stable extension stage. When the strain rate is in the range of 330 s−1 to 630 s−1, the dynamic tensile strength of graphite increases with increasing strain rate. The dynamic increase factor (DIF) of fine-grained graphite ranged from 1.05 to 1.2, while that of coarse-grained graphite was about 1.2 to 1.6. There is a large dispersion in the dynamic tensile strength of graphite when the strain rate is increased. It was found that the tensile strength of graphite improved considerably with increasing strain rate, while the fracture strain decreased slightly.","PeriodicalId":36762,"journal":{"name":"Journal of Nuclear Fuel Cycle and Waste Technology","volume":"3 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90649197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dispersed particle fuel is an advanced form of fuel. Due to the need for reactivity control, burnable poison particles and fuel particles are often dispersed in the matrix together. In order to prove the double dispersion mechanism of fuel and burnable poison particles with high calculation accuracy, a random dispersion model of burnable poison particles is constructed in this paper under the conditions of fuel homogenization and random dispersion of fuel particles. Compared with the random dispersion model, direct homogenization of fuel or burnable poison can cause large deviation in the calculation of system eigenvalues according to the MCX calculation. Under the same fuel phase volume, fuel enrichment and burnable poison loading, the maximum deviation can reach 1494pcm. The deviation increases with the increase of the loading mass of the burnable poison in the system, subject to fuel particle diameter of the order ∼100 μm. At a relatively high content of the burnable poison, the deviation decreases with the change of the content of the burnable poison. The calculation results show that the double heterogeneity effect of the system composed of fuel and burnable poison particles cannot be ignored, and the traditional homogenization calculation method must be corrected according to the actual situation. This paper is of valuable reference for the calculation and correction of dispersion fuel homogenization under the condition of strong absorber, and the program development and verification of using a new method to deal with the double heterogeneity effect.
{"title":"Analysis of Double Heterogeneous Effect Under Double Dispersion of Fuel and Burnable Poison Particles","authors":"Anmin Yuan, Hongchun Wu, Yunzhao Li, Liangzhi Cao, Cong Wang, Chaofei Jiang, Shengzhi Yu, Qianglong Wang, Jinrong Qiu","doi":"10.1115/icone29-91463","DOIUrl":"https://doi.org/10.1115/icone29-91463","url":null,"abstract":"\u0000 Dispersed particle fuel is an advanced form of fuel. Due to the need for reactivity control, burnable poison particles and fuel particles are often dispersed in the matrix together. In order to prove the double dispersion mechanism of fuel and burnable poison particles with high calculation accuracy, a random dispersion model of burnable poison particles is constructed in this paper under the conditions of fuel homogenization and random dispersion of fuel particles. Compared with the random dispersion model, direct homogenization of fuel or burnable poison can cause large deviation in the calculation of system eigenvalues according to the MCX calculation. Under the same fuel phase volume, fuel enrichment and burnable poison loading, the maximum deviation can reach 1494pcm. The deviation increases with the increase of the loading mass of the burnable poison in the system, subject to fuel particle diameter of the order ∼100 μm. At a relatively high content of the burnable poison, the deviation decreases with the change of the content of the burnable poison. The calculation results show that the double heterogeneity effect of the system composed of fuel and burnable poison particles cannot be ignored, and the traditional homogenization calculation method must be corrected according to the actual situation. This paper is of valuable reference for the calculation and correction of dispersion fuel homogenization under the condition of strong absorber, and the program development and verification of using a new method to deal with the double heterogeneity effect.","PeriodicalId":36762,"journal":{"name":"Journal of Nuclear Fuel Cycle and Waste Technology","volume":"127 2 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79579522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During the service of the reactor, the zirconium alloy will inevitably interact with hydrogen to form zirconium hydride, which will adversely affect its mechanical properties. In this paper, the first-principles software VASP is used to analyze the phase transition of zirconium hydride, and based on the results, the subprogram of MAAP4 integrated analysis for severe accidents is optimized to further analyze the interaction between zirconium alloy cladding and hydrogen. Verification. The results show that the diffusion equation has large calculation potential and high calculation accuracy for the effect of zirconium hydride with obvious phase transition, and can realize the hydrogen performance analysis of the cladding material in the reactor. At the same time, VASP shows that δ – ZrH1.5 is the main component of cladding material hydrogenation It is also the main reason for brittle transition.
{"title":"Analysis of Hydrogenation Properties of Nuclear Fuel Zirconium Alloy Cladding","authors":"Lin Qin","doi":"10.1115/icone29-89580","DOIUrl":"https://doi.org/10.1115/icone29-89580","url":null,"abstract":"\u0000 During the service of the reactor, the zirconium alloy will inevitably interact with hydrogen to form zirconium hydride, which will adversely affect its mechanical properties. In this paper, the first-principles software VASP is used to analyze the phase transition of zirconium hydride, and based on the results, the subprogram of MAAP4 integrated analysis for severe accidents is optimized to further analyze the interaction between zirconium alloy cladding and hydrogen. Verification. The results show that the diffusion equation has large calculation potential and high calculation accuracy for the effect of zirconium hydride with obvious phase transition, and can realize the hydrogen performance analysis of the cladding material in the reactor. At the same time, VASP shows that δ – ZrH1.5 is the main component of cladding material hydrogenation It is also the main reason for brittle transition.","PeriodicalId":36762,"journal":{"name":"Journal of Nuclear Fuel Cycle and Waste Technology","volume":"18 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88577169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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