The erosion of pipe walls by particle in supercritical carbon dioxide (SCO2) has a significant impact on the safe operation of the reactor, therefore, a simulation study of the wall erosion pattern of particulate matter within the SCO2 in the bent pipe channel was carried out. The research results show that SCO2 is extruded to the outer wall side under the action of centrifugal force. At the same time, two symmetrical secondary flows are formed in the elbow area, in the range of angle 60°–75°, the flow line is the most intensive and the secondary flow phenomenon is the most obvious; the erosion of particulate matter on the pipe is mainly concentrated in the outer side of the elbow area; with the increase of mass flow velocity, the erosion rate of particulate matter on the wall surface gradually increases. And the effect of increasing mass flow velocity on the erosion rate is nearly linear; the increase of particle diameter will lead to the first increase and then decrease of erosion; when the density of particles increases, the erosion rate of particles on the wall decreases, but the effect is low.
{"title":"Numerical investigation of particle erosion characteristics in supercritical carbon dioxide in elbow pipe channels","authors":"Peng Xu, T. Zhou, Zhongguan Fu, J. Chen","doi":"10.1115/icone29-88843","DOIUrl":"https://doi.org/10.1115/icone29-88843","url":null,"abstract":"\u0000 The erosion of pipe walls by particle in supercritical carbon dioxide (SCO2) has a significant impact on the safe operation of the reactor, therefore, a simulation study of the wall erosion pattern of particulate matter within the SCO2 in the bent pipe channel was carried out. The research results show that SCO2 is extruded to the outer wall side under the action of centrifugal force. At the same time, two symmetrical secondary flows are formed in the elbow area, in the range of angle 60°–75°, the flow line is the most intensive and the secondary flow phenomenon is the most obvious; the erosion of particulate matter on the pipe is mainly concentrated in the outer side of the elbow area; with the increase of mass flow velocity, the erosion rate of particulate matter on the wall surface gradually increases. And the effect of increasing mass flow velocity on the erosion rate is nearly linear; the increase of particle diameter will lead to the first increase and then decrease of erosion; when the density of particles increases, the erosion rate of particles on the wall decreases, but the effect is low.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115702695","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}
Due to the fact that the Cr-coated Zircalloy and the FeCrAl alloy have excellent high-temperature oxidation resistance, corrosion resistance, they are considered to be potential replacement materials for PWR cladding. However, it is also reported that the poor tritium resistance of FeCrAl alloy will accelerate the penetration of tritium throughout the cladding and increase the treatment cost. In this work, the physical models and tritium migration models of Cr-coated Zircalloy cladding and FeCrAl claddingare reviewed firstly. Then, based on the developed fuel performance analysis code CAMPUS, the fuel performance models of Cr-coated Zircalloy cladding and FeCrAl cladding are implemented, and a new model of the tritium migration in different claddings is implemented too. Finally, the performances of three fuel cladding combinations (UO2 pellets and Zircalloy cladding, Cr-coated Zircalloy cladding and FeCrAl cladding) under normal and LOCA conditions are simulated and discussed. And the tritium resistance performance of different fuel cladding combinations is further calculated and analyzed with the new tritium migration model. The calculation results show that under normal and LOCA conditions, compared with Zircalloy cladding, the application of FeCrAl cladding can reduce the overall temperature of fuel and improve fuel safety margin. And the application of Cr-coated Zircalloy cladding and FeCrAl cladding can effectively delay the failure time of cladding under LOCA condition; In terms of tritium penetration, the Cr-coated Zircalloy is found to have better tritium resistance effect than FeCrAl alloy, which greatly reduces the pollution treatment cost of reactor operation.
{"title":"Multiphysics Analysis of Fuel Performance and Tritium Migration in FeCrAl and Cr-Coated Zircalloy Cladding Under PWR Normal Operating and Transient Conditions","authors":"Rong Liu, Liwen Yang, S. Liu","doi":"10.1115/icone29-91981","DOIUrl":"https://doi.org/10.1115/icone29-91981","url":null,"abstract":"\u0000 Due to the fact that the Cr-coated Zircalloy and the FeCrAl alloy have excellent high-temperature oxidation resistance, corrosion resistance, they are considered to be potential replacement materials for PWR cladding. However, it is also reported that the poor tritium resistance of FeCrAl alloy will accelerate the penetration of tritium throughout the cladding and increase the treatment cost. In this work, the physical models and tritium migration models of Cr-coated Zircalloy cladding and FeCrAl claddingare reviewed firstly. Then, based on the developed fuel performance analysis code CAMPUS, the fuel performance models of Cr-coated Zircalloy cladding and FeCrAl cladding are implemented, and a new model of the tritium migration in different claddings is implemented too. Finally, the performances of three fuel cladding combinations (UO2 pellets and Zircalloy cladding, Cr-coated Zircalloy cladding and FeCrAl cladding) under normal and LOCA conditions are simulated and discussed. And the tritium resistance performance of different fuel cladding combinations is further calculated and analyzed with the new tritium migration model. The calculation results show that under normal and LOCA conditions, compared with Zircalloy cladding, the application of FeCrAl cladding can reduce the overall temperature of fuel and improve fuel safety margin. And the application of Cr-coated Zircalloy cladding and FeCrAl cladding can effectively delay the failure time of cladding under LOCA condition; In terms of tritium penetration, the Cr-coated Zircalloy is found to have better tritium resistance effect than FeCrAl alloy, which greatly reduces the pollution treatment cost of reactor operation.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125061680","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}
Online composition analysis is a crucial method for energy-saving and environment-friendly cement industry. A prompt gamma neutron activation analysis (PGNAA) system, which is aimed to determine the elemental concentrations of cement sample, has been designed and optimized by the Monte Carlo approach. This system consists of a 2 × 2” Bismuth Germanate (BGO) scintillation detector, a portable D-D neutron generator, a multi-channel analyzer, the reflector, the moderator and the shield. Out of consideration for minimization of costs and maximization of the thermal neutron flux at the output surface, different models of reflectors and moderators were tested in the MCNP code. Meanwhile, lead shield was also designed to reduce gamma-ray background produced by the nature and the system itself. In addition, simulated spectra of a standard cement sample were obtained to test the performance of this system. For ensuring the safety of the system operators, the dose rate distribution around the system were evaluated. The results demonstrated the feasibility of adopting this optimized design for chemical composition analysis of cement sample, and provided data reference for similar research. Eventually, an in-situ system has been established for further study.
{"title":"Design and Optimization of a PGNAA System Based on D-D Neutron Generator for Cement Composition Analysis","authors":"Si-Yuan Chen, Guang-Hao Li, Shaomin Jia, Zhao-Hu Lu, De-Dong He, Gong Ke, Guang Shi, Shiwei Jing","doi":"10.1115/icone29-91972","DOIUrl":"https://doi.org/10.1115/icone29-91972","url":null,"abstract":"\u0000 Online composition analysis is a crucial method for energy-saving and environment-friendly cement industry. A prompt gamma neutron activation analysis (PGNAA) system, which is aimed to determine the elemental concentrations of cement sample, has been designed and optimized by the Monte Carlo approach. This system consists of a 2 × 2” Bismuth Germanate (BGO) scintillation detector, a portable D-D neutron generator, a multi-channel analyzer, the reflector, the moderator and the shield. Out of consideration for minimization of costs and maximization of the thermal neutron flux at the output surface, different models of reflectors and moderators were tested in the MCNP code. Meanwhile, lead shield was also designed to reduce gamma-ray background produced by the nature and the system itself. In addition, simulated spectra of a standard cement sample were obtained to test the performance of this system. For ensuring the safety of the system operators, the dose rate distribution around the system were evaluated. The results demonstrated the feasibility of adopting this optimized design for chemical composition analysis of cement sample, and provided data reference for similar research. Eventually, an in-situ system has been established for further study.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"530 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123573809","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}
This paper studies the response of γ-ray ionizing radiation under the irradiation of single active Pixel Sensor in the irradiation chamber and the Calibration Chamber, Designs Radiation Experiments, and analyzes and discusses the characteristic values in different statistical regions of pixels in the bright and dark environment, the linear relationship and dispersion degree between the statistical eigenvalue and the dose rate under different statistical algorithms are studied. The experimental results show that in the dark environment, the background gray values of any region in the image are in the range of 10–30, and the eigenvalue have a good linear response. Under the bright environment, the global region of the image will be confused with the neighboring region because of the different background gray values of the color region in the Byer array, which will affect the characterization of the dose rate. In low dose rate, the signal of radiation response is too small, dark current and background dark noise produce interference signal, so the signal-to-noise ratio is too low, and 300 frames of image data are needed to achieve the detection accuracy. In high dose rate, the response signal is strong, and 2 consecutive frames of image data are needed to achieve the detection accuracy. The characteristic value of threshold pixel at low dose rate is good, and the characteristic value of threshold Pixel and total gray value at high dose rate are good, which meet the requirement of wide range detection. In the radiation field experiment, we can choose the corresponding algorithm to detect the dose rate according to the field environment. This study provides theoretical basis and data support for improving gamma-ray dose rate detection technology based on MAPS image and realizing radiation field dose rate characterization. In order to use the static environment to do the radiation experiment, we can design an algorithm to cut the edge of the frame image, and use the computer image processing technology to choose the area which is advantageous to the dose rate Characterization, To realize radiation Detection in dynamic environment.
{"title":"The Characterization of Radiation Response for MAPS","authors":"Zhiwei Qin, Shoulong Xu, Hanfeng Dong","doi":"10.1115/icone29-92813","DOIUrl":"https://doi.org/10.1115/icone29-92813","url":null,"abstract":"\u0000 This paper studies the response of γ-ray ionizing radiation under the irradiation of single active Pixel Sensor in the irradiation chamber and the Calibration Chamber, Designs Radiation Experiments, and analyzes and discusses the characteristic values in different statistical regions of pixels in the bright and dark environment, the linear relationship and dispersion degree between the statistical eigenvalue and the dose rate under different statistical algorithms are studied. The experimental results show that in the dark environment, the background gray values of any region in the image are in the range of 10–30, and the eigenvalue have a good linear response. Under the bright environment, the global region of the image will be confused with the neighboring region because of the different background gray values of the color region in the Byer array, which will affect the characterization of the dose rate. In low dose rate, the signal of radiation response is too small, dark current and background dark noise produce interference signal, so the signal-to-noise ratio is too low, and 300 frames of image data are needed to achieve the detection accuracy. In high dose rate, the response signal is strong, and 2 consecutive frames of image data are needed to achieve the detection accuracy. The characteristic value of threshold pixel at low dose rate is good, and the characteristic value of threshold Pixel and total gray value at high dose rate are good, which meet the requirement of wide range detection. In the radiation field experiment, we can choose the corresponding algorithm to detect the dose rate according to the field environment. This study provides theoretical basis and data support for improving gamma-ray dose rate detection technology based on MAPS image and realizing radiation field dose rate characterization. In order to use the static environment to do the radiation experiment, we can design an algorithm to cut the edge of the frame image, and use the computer image processing technology to choose the area which is advantageous to the dose rate Characterization, To realize radiation Detection in dynamic environment.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126724893","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}
Song Ma, Zhong-ning Sun, Yanmin Zhou, Haifeng Gu, Lintai Li
As an important part of the ventilation system of nuclear facilities, the performance of filter is of great significance to the environment and personnel safety. With the operation of the filter, the filtration mode will change from depth filtration to surface filtration. In this paper, a numerical simulation method is developed for the unsteady deposition characteristics of particles in the surface filtration. The parcel injection model is applied to accelerate the formation and growth process of dust cake on the surface of fiber filter. A series of subroutines running in FLUENT environment are developed to enhance the capabilities of computational fluid dynamics code in ANSYS. The Brownian force is added to the DPM model to calculate the particle trajectory more accurately. The function that aerosol particles are intercepted and deposited on the surface of fiber filter to form dust cake is added. The porous media model is used to simulate the fiber filter and dust cake. The porosity and resistance coefficient change with the unsteady deposition of particles. Combined with the subroutine with FLUENT software, a numerical simulation method which can be used to predict the unsteady deposition characteristics of particles in the surface filtration is formed. The numerical simulation results are compared with the experimental results, and they are basically consistent. So the developed numerical simulation method can be used to predict the unsteady deposition characteristics of particles in the surface filtration, and can also provide a theoretical basis for the structural design of pleated filter.
{"title":"Study on Numerical Simulation Method of Unsteady Deposition Characteristics of Particles in Surface Filtration","authors":"Song Ma, Zhong-ning Sun, Yanmin Zhou, Haifeng Gu, Lintai Li","doi":"10.1115/icone29-93003","DOIUrl":"https://doi.org/10.1115/icone29-93003","url":null,"abstract":"\u0000 As an important part of the ventilation system of nuclear facilities, the performance of filter is of great significance to the environment and personnel safety. With the operation of the filter, the filtration mode will change from depth filtration to surface filtration. In this paper, a numerical simulation method is developed for the unsteady deposition characteristics of particles in the surface filtration. The parcel injection model is applied to accelerate the formation and growth process of dust cake on the surface of fiber filter. A series of subroutines running in FLUENT environment are developed to enhance the capabilities of computational fluid dynamics code in ANSYS. The Brownian force is added to the DPM model to calculate the particle trajectory more accurately. The function that aerosol particles are intercepted and deposited on the surface of fiber filter to form dust cake is added. The porous media model is used to simulate the fiber filter and dust cake. The porosity and resistance coefficient change with the unsteady deposition of particles. Combined with the subroutine with FLUENT software, a numerical simulation method which can be used to predict the unsteady deposition characteristics of particles in the surface filtration is formed. The numerical simulation results are compared with the experimental results, and they are basically consistent. So the developed numerical simulation method can be used to predict the unsteady deposition characteristics of particles in the surface filtration, and can also provide a theoretical basis for the structural design of pleated filter.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128431987","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}
In recent years, UN fuels have emerged as potential alternatives to UO2 fuels, due to its superior thermophysical properties, such as high thermal conductivity, melting point and fission density. And SiC is considered as one of the new generations of accident-tolerant cladding materials because of its excellent high temperature strength, creep resistance, lower thermal expansion and better irradiation performance. In this paper, the thermal and mechanical properties of the two-layered SiC cladding and UN fuel are reviewed. Then, based on the developed fuel performance analysis code CAMPUS, the multiphysics models of two-layered SiC cladding and UN fuel are implemented into the CAMPUS code. After that, the fuel performance of three fuel cladding systems, UN-two-layered SiC cladding, UN-Zircaloy cladding and UO2-Zircaloy cladding, are simulated and analyzed under both normal operating and accident conditions of PWR. Our calculation results show that using UN fuel can significantly reduce the maximum temperature of the fuel under LOCA condition, resulting in a significant delay in cladding failure time. Thus, the safety margin of the reactor can be improved. After the two-layered SiC cladding is further assembled, the failure time of fuel rod under accident condition is found to be effectively delayed due to better mechanical properties of SiC.
{"title":"Multiphysics Analysis of UN Fuel Performance With a Two-Layered SiC Cladding Under Multiple Operating Conditions in a Light Water Reactor","authors":"Rong Liu, Huiyun Han, S. Liu","doi":"10.1115/icone29-91980","DOIUrl":"https://doi.org/10.1115/icone29-91980","url":null,"abstract":"\u0000 In recent years, UN fuels have emerged as potential alternatives to UO2 fuels, due to its superior thermophysical properties, such as high thermal conductivity, melting point and fission density. And SiC is considered as one of the new generations of accident-tolerant cladding materials because of its excellent high temperature strength, creep resistance, lower thermal expansion and better irradiation performance. In this paper, the thermal and mechanical properties of the two-layered SiC cladding and UN fuel are reviewed. Then, based on the developed fuel performance analysis code CAMPUS, the multiphysics models of two-layered SiC cladding and UN fuel are implemented into the CAMPUS code. After that, the fuel performance of three fuel cladding systems, UN-two-layered SiC cladding, UN-Zircaloy cladding and UO2-Zircaloy cladding, are simulated and analyzed under both normal operating and accident conditions of PWR.\u0000 Our calculation results show that using UN fuel can significantly reduce the maximum temperature of the fuel under LOCA condition, resulting in a significant delay in cladding failure time. Thus, the safety margin of the reactor can be improved. After the two-layered SiC cladding is further assembled, the failure time of fuel rod under accident condition is found to be effectively delayed due to better mechanical properties of SiC.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128477729","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}
Steam generator (SG) is an important equipment of the nuclear power plant, and the stability of its liquid level affects the safe operation of the nuclear power plant. SG is a complex system with nonlinear, time-varying, nonminimum-phase, small stability margin and large time delay. In actual operation, it is difficult for classical PID control to ensure a satisfactory control performance. In this paper, the neural network methods are used to optimize the parameters of the PID controller, and a neural network controller is designed. The controller of the system consists of two components: a classical PID controller, which realizes control through a closed loop; a single-hidden-layer neural network based on the BP (back propagation) model. The neural network calculates the coefficients of the classic PID controller through matrix operations. Two weighting matrices are adjusted according to the gradient descent method to reduce the loss function and realize the training process. The control system is deployed to a SG simulation model through Simulink. The typical working conditions are simulated and investigated. The control performance is compared with that of the classical PID controller. Through analysis, it is confirmed that the neural network PID control system can meet the control requirements with fast response speed, short settling time, stable control effect under various working conditions, and strong anti-interference ability. The results prove that the neural network control has greater advantages and better application value than the classical PID controller.
{"title":"Design of Liquid Level Control System of Steam Generator Based on Neural Network PID Controller","authors":"Long Xiao, Peiwei Sun, Xinyu Wei","doi":"10.1115/icone29-91880","DOIUrl":"https://doi.org/10.1115/icone29-91880","url":null,"abstract":"\u0000 Steam generator (SG) is an important equipment of the nuclear power plant, and the stability of its liquid level affects the safe operation of the nuclear power plant. SG is a complex system with nonlinear, time-varying, nonminimum-phase, small stability margin and large time delay. In actual operation, it is difficult for classical PID control to ensure a satisfactory control performance.\u0000 In this paper, the neural network methods are used to optimize the parameters of the PID controller, and a neural network controller is designed. The controller of the system consists of two components: a classical PID controller, which realizes control through a closed loop; a single-hidden-layer neural network based on the BP (back propagation) model. The neural network calculates the coefficients of the classic PID controller through matrix operations. Two weighting matrices are adjusted according to the gradient descent method to reduce the loss function and realize the training process. The control system is deployed to a SG simulation model through Simulink. The typical working conditions are simulated and investigated. The control performance is compared with that of the classical PID controller.\u0000 Through analysis, it is confirmed that the neural network PID control system can meet the control requirements with fast response speed, short settling time, stable control effect under various working conditions, and strong anti-interference ability. The results prove that the neural network control has greater advantages and better application value than the classical PID controller.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126899674","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}
Ryusuke Koie, M. Kawaguchi, S. Miyahara, Masayoshi Uno, H. Seino
In a postulated accident of fuel pin failure of a sodium-cooled fast reactor, a fission product of cesium will be released from the failed pin as an aerosol such as cesium iodide and/or cesium oxide together with a fission product noble gas such as xenon and krypton. The xenon and krypton released with the cesium aerosols into the sodium coolant as bubbles have an influence on the removal of cesium aerosols by the sodium pool in a period of bubble rising to the sodium pool surface. Then, the cesium aerosols could transfer into the containment vessel as an initial inventory of a source term. To meet this target, we have developed the computer program AESOP that deals with the expansion and the deformation of the bubble together with the aerosol absorption and researched the sensitivities of the physical parameters on decontamination factor (DF) of cesium aerosols such as the initial bubble diameter, sodium pool depth, and temperature, aerosol particle diameter, and density, initial aerosol concentration in the bubble in previous our papers. In this study, we performed a water simulation test to measure the DFs of simulant aerosols with nitrogen gas bubbles rising through the water pool for the code validation. The experiments revealed that the DFs increased with the increase in the aerosol diameter and the water pool depth.
{"title":"A Study on Removal Mechanisms of Cesium Aerosol From Noble Gas Bubble in Sodium Pool (III) Measurement of Decontamination Factors in Water Simulation Test","authors":"Ryusuke Koie, M. Kawaguchi, S. Miyahara, Masayoshi Uno, H. Seino","doi":"10.1115/icone29-94057","DOIUrl":"https://doi.org/10.1115/icone29-94057","url":null,"abstract":"\u0000 In a postulated accident of fuel pin failure of a sodium-cooled fast reactor, a fission product of cesium will be released from the failed pin as an aerosol such as cesium iodide and/or cesium oxide together with a fission product noble gas such as xenon and krypton. The xenon and krypton released with the cesium aerosols into the sodium coolant as bubbles have an influence on the removal of cesium aerosols by the sodium pool in a period of bubble rising to the sodium pool surface. Then, the cesium aerosols could transfer into the containment vessel as an initial inventory of a source term. To meet this target, we have developed the computer program AESOP that deals with the expansion and the deformation of the bubble together with the aerosol absorption and researched the sensitivities of the physical parameters on decontamination factor (DF) of cesium aerosols such as the initial bubble diameter, sodium pool depth, and temperature, aerosol particle diameter, and density, initial aerosol concentration in the bubble in previous our papers.\u0000 In this study, we performed a water simulation test to measure the DFs of simulant aerosols with nitrogen gas bubbles rising through the water pool for the code validation. The experiments revealed that the DFs increased with the increase in the aerosol diameter and the water pool depth.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129226960","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}
Y. Nishimura, Mohammad Allaf, Shoichiro Okita, M. Goto, K. Okamoto
Proposed higher power density HTGR by removing the graphite sleeve and implementing the SiC matrix fuel compact has neutronics problem on criticality. Present study selected Er burnable poison and Pu fissile material as possible candidate to compensate the reactivity. To ensure core performance of HTTR modeled reactors, the various tests were carried out using Serpent 2 code, and nuclear characteristic data were obtained successfully. The obtained results verified the expected characteristics. It was demonstrated that both Er and Pu solved criticality issue. Furthermore, especially Pu-loaded core showed better burn-up performance compared to current HTGR. One possible option that proposed reactor can also burn Pu safely based on the concept of small-Clean Burn-HTGR was concluded.
{"title":"Preliminary Core Calculation on Reactivity Compensation for SiC Matrix Fuel Compact HTTR With Erbium Burnable Poison and Plutonium Fissile Material","authors":"Y. Nishimura, Mohammad Allaf, Shoichiro Okita, M. Goto, K. Okamoto","doi":"10.1115/icone29-91703","DOIUrl":"https://doi.org/10.1115/icone29-91703","url":null,"abstract":"\u0000 Proposed higher power density HTGR by removing the graphite sleeve and implementing the SiC matrix fuel compact has neutronics problem on criticality. Present study selected Er burnable poison and Pu fissile material as possible candidate to compensate the reactivity. To ensure core performance of HTTR modeled reactors, the various tests were carried out using Serpent 2 code, and nuclear characteristic data were obtained successfully. The obtained results verified the expected characteristics. It was demonstrated that both Er and Pu solved criticality issue. Furthermore, especially Pu-loaded core showed better burn-up performance compared to current HTGR. One possible option that proposed reactor can also burn Pu safely based on the concept of small-Clean Burn-HTGR was concluded.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114536428","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 two-dimensional (2D) system analysis codes are usually used to design and analyze the modular pebble-bed High Temperature Gas-cooled Reactors (HTR). However, in some cases, three-dimensional (3D) characteristics, for example the 3D power distribution and temperature distribution due to a part of control rods movement, also need to be concerned. In this paper, based on the 200 MWe Pebble-bed Modular High Temperature gas-cooled Reactor (HTR-PM) design, a 3D system analysis code was used to analyze some three-dimensional characteristics in steady state, as well as the transient process caused by the asymmetric movement of control rods in the side reflectors. Under normal operations of HTR-PM, the control rods are inserted at certain heights and the primary coolant enters the Reactor Pressure Vessel (RPV) from the outer pipe of the coaxial hot gas duct. As a result, the fuel temperature has a relative circumferential deviation of about 1.64% on the outside of the pebble bed, while a very small deviation at the center of the bed. The temperature distribution of RPV is significantly affected by the position of the helium inlet as well. The analysis results showed that, during the transient process caused by the withdrawal of two control rods, the relative circumferential deviation of the fuel particle temperature on the outside of the pebble bed would increase to around 8.47%. However, because of heat conduction in relatively long distance, the movement of the control rods has very little effect on the circumferential temperature deviation of the fuel particles at the center of the bed. These 3D characteristics of HTR under different conditions demonstrate the good applicability of 2D and 3D system codes and will provide support for more accurate safety analyses in the future.
{"title":"Preliminary Study on Three-Dimensional Characteristics of Modular High Temperature Gas-Cooled Reactor","authors":"Haojie Zhang, Yanhua Zheng, D. She, Lei Shi","doi":"10.1115/icone29-91754","DOIUrl":"https://doi.org/10.1115/icone29-91754","url":null,"abstract":"\u0000 The two-dimensional (2D) system analysis codes are usually used to design and analyze the modular pebble-bed High Temperature Gas-cooled Reactors (HTR). However, in some cases, three-dimensional (3D) characteristics, for example the 3D power distribution and temperature distribution due to a part of control rods movement, also need to be concerned. In this paper, based on the 200 MWe Pebble-bed Modular High Temperature gas-cooled Reactor (HTR-PM) design, a 3D system analysis code was used to analyze some three-dimensional characteristics in steady state, as well as the transient process caused by the asymmetric movement of control rods in the side reflectors.\u0000 Under normal operations of HTR-PM, the control rods are inserted at certain heights and the primary coolant enters the Reactor Pressure Vessel (RPV) from the outer pipe of the coaxial hot gas duct. As a result, the fuel temperature has a relative circumferential deviation of about 1.64% on the outside of the pebble bed, while a very small deviation at the center of the bed. The temperature distribution of RPV is significantly affected by the position of the helium inlet as well. The analysis results showed that, during the transient process caused by the withdrawal of two control rods, the relative circumferential deviation of the fuel particle temperature on the outside of the pebble bed would increase to around 8.47%. However, because of heat conduction in relatively long distance, the movement of the control rods has very little effect on the circumferential temperature deviation of the fuel particles at the center of the bed. These 3D characteristics of HTR under different conditions demonstrate the good applicability of 2D and 3D system codes and will provide support for more accurate safety analyses in the future.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121643661","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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