The flow field calculation plays a crucial role in thermal-hydraulic calculation of High Temperature Gas-cooled Reactor (HTGR). While using the thermal-hydraulic program for HTGR to calculate the low-flow condition, the calculation of the helium pressure field distribution in the reactor core is difficult to converge, which may lead to the non-physical pressure oscillation. The analysis and improvement of flow field calculation to alleviate this non-physical oscillation is of great significance for HTGR thermal-hydraulic design. In this work, the factors affecting the flow field calculation are analyzed. The approximation assumptions of horizontal cavity modeling and the using of Gauss-Seidel (GS) partition point iteration method leading to the flow field calculation is sensitive to round-off error. For the reason of GS partition point iterative method suffers from the slow convergence rate, and may even non-convergence in some conditions, a global direct method is developed in this paper to solve the whole flow field directly to pursue strong stability and high convergence rate. Compared with original method, the numerical results show that the newly developed algorithm achieves faster convergence rate and stricter convergence results.
{"title":"Analysis and Improvement of Flow Field Calculation in Thermal Hydraulic Program for High Temperature Gas-Cooled Reactor","authors":"Dou Haoming, Lang Minggang, Z. Han, She Ding","doi":"10.1115/icone29-92090","DOIUrl":"https://doi.org/10.1115/icone29-92090","url":null,"abstract":"\u0000 The flow field calculation plays a crucial role in thermal-hydraulic calculation of High Temperature Gas-cooled Reactor (HTGR). While using the thermal-hydraulic program for HTGR to calculate the low-flow condition, the calculation of the helium pressure field distribution in the reactor core is difficult to converge, which may lead to the non-physical pressure oscillation. The analysis and improvement of flow field calculation to alleviate this non-physical oscillation is of great significance for HTGR thermal-hydraulic design. In this work, the factors affecting the flow field calculation are analyzed. The approximation assumptions of horizontal cavity modeling and the using of Gauss-Seidel (GS) partition point iteration method leading to the flow field calculation is sensitive to round-off error. For the reason of GS partition point iterative method suffers from the slow convergence rate, and may even non-convergence in some conditions, a global direct method is developed in this paper to solve the whole flow field directly to pursue strong stability and high convergence rate. Compared with original method, the numerical results show that the newly developed algorithm achieves faster convergence rate and stricter convergence results.","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":"131175172","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}
Compared with offline simulation based on software completely, Hardware-in-the-loop Simulation (HILS) is a simulation method based on software and hardware coupling, which can not only verify the principle of the model studied, but also feedback hardware response for comparison, shorten product test cycle, improve research and development efficiency and accuracy. Taking the marine nuclear reactor as the background, this paper modelled the main circuit of energy power and the part of propulsion power output, simulated the energy power module offline based on Modelica language, and coupled Arduino MCU with LEGO parts to simulate the hardware response of propulsion power output. This study used OpenModelica to construct the steady-state and transient simulation operation of the off-line simulation model, realized the interaction between the hardware signal input and the offline simulation model, processed the mechanical response of the simulation output and communicated with the external hardware. Finally, the feedback action response was compared with the key parameters in the existing literature. The results show that the simulation results of the model and the hardware response feedback results are consistent with the literature parameters, and based on the coupling of Modelica language with Arduino MCU can carry out the HILS for the marine nuclear power system in steady state and transient state.
{"title":"Propulsion Control of Marine Nuclear Reactor by Hardware-in-the-Loop Simulation (HILS)","authors":"Ao Zhang, Xiang Wang","doi":"10.1115/icone29-91544","DOIUrl":"https://doi.org/10.1115/icone29-91544","url":null,"abstract":"\u0000 Compared with offline simulation based on software completely, Hardware-in-the-loop Simulation (HILS) is a simulation method based on software and hardware coupling, which can not only verify the principle of the model studied, but also feedback hardware response for comparison, shorten product test cycle, improve research and development efficiency and accuracy. Taking the marine nuclear reactor as the background, this paper modelled the main circuit of energy power and the part of propulsion power output, simulated the energy power module offline based on Modelica language, and coupled Arduino MCU with LEGO parts to simulate the hardware response of propulsion power output. This study used OpenModelica to construct the steady-state and transient simulation operation of the off-line simulation model, realized the interaction between the hardware signal input and the offline simulation model, processed the mechanical response of the simulation output and communicated with the external hardware. Finally, the feedback action response was compared with the key parameters in the existing literature. The results show that the simulation results of the model and the hardware response feedback results are consistent with the literature parameters, and based on the coupling of Modelica language with Arduino MCU can carry out the HILS for the marine nuclear power system in steady state and transient state.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"39 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":"132578791","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 three-dimensional (3D) computational fluid dynamics (CFD) investigation of steam flow distribution of a cross-flow X-type steam superheater in a small modular reactor (SMR) has been carried out, and different flow distributors have been compared. As a non-baffle shell and tube heat exchanger, the secondary steam flow of the superheater flows across the tube bundles and is superheated in the shell side. The flow distributor is arranged between the shell side inlet and the tube bundles, devices compared are the impingement plate and orifice plate. The diameter and the geometry distribution of the holes on the orifice plate have also been researched. The software used is ANSYS FLUENT, applying standard k-epsilon turbulence flow model. Distribution of velocity and pressure drop of the shell-side steam is obtained. As the analysis of the flow-field distribution contributes to optimizing the heat exchange performance, the analysis solutions can provide helpful information for the superheater design.
{"title":"CFD Analysis of the Steam Side in a Cross-Flow X-Type Steam Superheater","authors":"S. Zhao, Weihua Li, Wentao Hao, Wenwen Zhang","doi":"10.1115/icone29-91387","DOIUrl":"https://doi.org/10.1115/icone29-91387","url":null,"abstract":"\u0000 A three-dimensional (3D) computational fluid dynamics (CFD) investigation of steam flow distribution of a cross-flow X-type steam superheater in a small modular reactor (SMR) has been carried out, and different flow distributors have been compared. As a non-baffle shell and tube heat exchanger, the secondary steam flow of the superheater flows across the tube bundles and is superheated in the shell side. The flow distributor is arranged between the shell side inlet and the tube bundles, devices compared are the impingement plate and orifice plate. The diameter and the geometry distribution of the holes on the orifice plate have also been researched. The software used is ANSYS FLUENT, applying standard k-epsilon turbulence flow model. Distribution of velocity and pressure drop of the shell-side steam is obtained. As the analysis of the flow-field distribution contributes to optimizing the heat exchange performance, the analysis solutions can provide helpful information for the superheater design.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"13 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":"132750564","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}
Raka Firman Baskara Permana, Junpei Tabuchi, T. Okawa, Yuki Narushima, Hajime Furuichi, K. Katono
Study on the droplet entrainment in annular two-phase flow has attracted many researchers in connection with the liquid film dryout in the annular two-phase flow. However, the knowledge on the entrainment due to nucleate boiling is still insufficient to predict the droplet entrainment rate accurately. In this study, measurements were made of the droplet entrainment rate with falling liquid films on the locally heated test section. The visualization using a high-speed camera to clarify the accuracy of the measurement results also carried out in this experiment. For the first step in this study, the measurement of the droplet entrainment rate was performed after getting a stable or steady state conditions. Then, we investigated the influence of the separator position on the reproducibility of the droplet entrainment rate to get the droplet entrainment rate – separator position map. As a result, the reproducibility of the droplet entrainment rate increases with decreasing separation distance from the liquid film. In additions, we also investigated the influence of the heat flux and liquid film flow rate on the reproducibility of the droplet entrainment rate. As a result, the reproducibility of the droplet entrainment rate increases with increasing the heat flux and liquid film flow rate. In the future, we expect to investigate the influence of gas flow rate, and degree of subcooling on the reproducibility of the droplet entrainment rate and some correlation models are developed.
{"title":"Experimental Study on Measurement of Boiling Entrainment Rate From Falling Liquid Film With Gas Sheared Flow","authors":"Raka Firman Baskara Permana, Junpei Tabuchi, T. Okawa, Yuki Narushima, Hajime Furuichi, K. Katono","doi":"10.1115/icone29-90420","DOIUrl":"https://doi.org/10.1115/icone29-90420","url":null,"abstract":"\u0000 Study on the droplet entrainment in annular two-phase flow has attracted many researchers in connection with the liquid film dryout in the annular two-phase flow. However, the knowledge on the entrainment due to nucleate boiling is still insufficient to predict the droplet entrainment rate accurately. In this study, measurements were made of the droplet entrainment rate with falling liquid films on the locally heated test section. The visualization using a high-speed camera to clarify the accuracy of the measurement results also carried out in this experiment. For the first step in this study, the measurement of the droplet entrainment rate was performed after getting a stable or steady state conditions. Then, we investigated the influence of the separator position on the reproducibility of the droplet entrainment rate to get the droplet entrainment rate – separator position map. As a result, the reproducibility of the droplet entrainment rate increases with decreasing separation distance from the liquid film. In additions, we also investigated the influence of the heat flux and liquid film flow rate on the reproducibility of the droplet entrainment rate. As a result, the reproducibility of the droplet entrainment rate increases with increasing the heat flux and liquid film flow rate. In the future, we expect to investigate the influence of gas flow rate, and degree of subcooling on the reproducibility of the droplet entrainment rate and some correlation models are developed.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"15 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":"132041254","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 irradiation mechanism of iron-based alloys has proven to be related to dislocation movement and interaction between dislocation and irradiation defect. Fe is an important element of the iron-based alloys. The single crystal iron is selected as the material of the indenter and the substrate when molecular dynamics (MD) simulation is launched. This article studies the effect of the different temperature and potential functions on the dislocation evolution and mechanical properties of single crystal iron in the nanoindentation process. Results show that temperature affects the load-displacement curve; the potential has no effect on the trend of the load-displacement curve, but it has an impact on the value of the load; the dislocation behavior of the substrate after compression results in a jagged load-displacement curve (pop-in event). These results are of great significance for understanding the dislocation behavior of the typical body centered cubic (BCC) metal during nanoindentation process.
{"title":"Effect of Temperature and Potential on BCC-Fe Nanoindentation Process","authors":"Dexing Wang, P. Lin, Libin Sun, Z. Cai","doi":"10.1115/icone29-91251","DOIUrl":"https://doi.org/10.1115/icone29-91251","url":null,"abstract":"\u0000 The irradiation mechanism of iron-based alloys has proven to be related to dislocation movement and interaction between dislocation and irradiation defect. Fe is an important element of the iron-based alloys. The single crystal iron is selected as the material of the indenter and the substrate when molecular dynamics (MD) simulation is launched. This article studies the effect of the different temperature and potential functions on the dislocation evolution and mechanical properties of single crystal iron in the nanoindentation process.\u0000 Results show that temperature affects the load-displacement curve; the potential has no effect on the trend of the load-displacement curve, but it has an impact on the value of the load; the dislocation behavior of the substrate after compression results in a jagged load-displacement curve (pop-in event). These results are of great significance for understanding the dislocation behavior of the typical body centered cubic (BCC) metal during nanoindentation process.","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":"131383428","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}
Heng Zhang, Xue Lyu, Qin Hang, Yulu Du, Bo Liu, Qun Liu, Guo-Zhen Wang, Jinchao Liu
An accurate measurement for the modality and motion parameters of bubbles is of great significance. In the existing bubble measurement methods, there are some problems that are desirable to be solved, such as system complexity, poor real-time performance, and the deviation due to two-dimensional measurement. To overcome these challenges, we developed a novel three-dimensional analysis method based on light field imaging diagnosis and deep learning algorithm. Different from traditional two-dimensional reconstruction, the bubble depth can be computed from light field images directly through digital refocusing technology. After calibrating, the conversion between the camera coordinate system and the real-world coordinate system is achieved through the sharpness evaluation algorithm. According to the corresponding relationship, the refocused image could be calibrated to the actual position in real world. Combined with the Multi-input Residual Convolution Neural Network, (MRCNN), the bubble depth could be computed fully automated from given images at high accuracy. Based on the above works, the three-dimensional reconstruction model for bubble flow can be established by coupling the depth and the parameters extracted through bounding boxes. The proposed method solves the problem that conventional imaging can only perform the two-dimensional measurement, which contributes to the error during the measurement process. Results show a promising performance on the three-dimensional reconstruction of bubble flow, validating the feasibility of the three-dimensional measurement method for bubbles in gas-liquid two-phase flow based on light field imaging diagnosis and deep learning algorithm.
{"title":"Deep-Learning Based Three-Dimensional Analysis of Bubble Flows From Light Field Images","authors":"Heng Zhang, Xue Lyu, Qin Hang, Yulu Du, Bo Liu, Qun Liu, Guo-Zhen Wang, Jinchao Liu","doi":"10.1115/icone29-91353","DOIUrl":"https://doi.org/10.1115/icone29-91353","url":null,"abstract":"\u0000 An accurate measurement for the modality and motion parameters of bubbles is of great significance. In the existing bubble measurement methods, there are some problems that are desirable to be solved, such as system complexity, poor real-time performance, and the deviation due to two-dimensional measurement. To overcome these challenges, we developed a novel three-dimensional analysis method based on light field imaging diagnosis and deep learning algorithm. Different from traditional two-dimensional reconstruction, the bubble depth can be computed from light field images directly through digital refocusing technology. After calibrating, the conversion between the camera coordinate system and the real-world coordinate system is achieved through the sharpness evaluation algorithm. According to the corresponding relationship, the refocused image could be calibrated to the actual position in real world. Combined with the Multi-input Residual Convolution Neural Network, (MRCNN), the bubble depth could be computed fully automated from given images at high accuracy. Based on the above works, the three-dimensional reconstruction model for bubble flow can be established by coupling the depth and the parameters extracted through bounding boxes. The proposed method solves the problem that conventional imaging can only perform the two-dimensional measurement, which contributes to the error during the measurement process. Results show a promising performance on the three-dimensional reconstruction of bubble flow, validating the feasibility of the three-dimensional measurement method for bubbles in gas-liquid two-phase flow based on light field imaging diagnosis and deep learning algorithm.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"12 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":"124377276","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 coolant may vaporize in the centrifugal pump to cause cavitation in pool-type nuclear heating reactor. Installing a jetting device at the pump suction port is an effective means of applying jetting technology to solve the problem of preventing cavitation in centrifugal pumps. In this paper, an annular multi-nozzles ejector was designed and an experimental system was constructed to test the actual supercharging performance of the device. When the high-energy fluid at the pump outlet flowed through the device, it was first mixed uniformly in the annular chamber, and then injected through the nozzles to mix with the main flow to increase the pressure of the main flow. The static pressure at the suction port of the pump increased. Accordingly, the available Net Positive Suction Head (NPSHa) of the pump increased. The test was constructed around the total flow flux through the pump invariable and the main loop flow flux invariable two schemes. The results show that when the proportion of the return flow flux was same, the greater the total flow flux through the pump, the higher the pressure increment at the pump suction port; when the proportion of the return flow flux was larger, the difference in the pressure increment corresponding to different total flow fluxes was larger. When the flow flux through the main circuit of the system was same, the pressure increment increased nonlinearly with the increase of the return flow flux. Increasing the return flow flux was beneficial to the supercharging performance of the jetting device.
{"title":"Research on the Supercharging Performance of the Annular Multi-Nozzles Ejector at the Suction Port of a Centrifugal Pump","authors":"Fubing Ma, Guangming Fan, Junxiu Xu, Changqi Yan, Shuai Hao, Yuning Zhou","doi":"10.1115/icone29-93123","DOIUrl":"https://doi.org/10.1115/icone29-93123","url":null,"abstract":"\u0000 The coolant may vaporize in the centrifugal pump to cause cavitation in pool-type nuclear heating reactor. Installing a jetting device at the pump suction port is an effective means of applying jetting technology to solve the problem of preventing cavitation in centrifugal pumps. In this paper, an annular multi-nozzles ejector was designed and an experimental system was constructed to test the actual supercharging performance of the device. When the high-energy fluid at the pump outlet flowed through the device, it was first mixed uniformly in the annular chamber, and then injected through the nozzles to mix with the main flow to increase the pressure of the main flow. The static pressure at the suction port of the pump increased. Accordingly, the available Net Positive Suction Head (NPSHa) of the pump increased. The test was constructed around the total flow flux through the pump invariable and the main loop flow flux invariable two schemes. The results show that when the proportion of the return flow flux was same, the greater the total flow flux through the pump, the higher the pressure increment at the pump suction port; when the proportion of the return flow flux was larger, the difference in the pressure increment corresponding to different total flow fluxes was larger. When the flow flux through the main circuit of the system was same, the pressure increment increased nonlinearly with the increase of the return flow flux. Increasing the return flow flux was beneficial to the supercharging performance of the jetting device.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"38 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":"128378242","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}
Konstantinos Gkouliaras, Jake Marr, Vasileios Theos, S. Chatzidakis
Recent and future advancements in the upcoming digital era of Nuclear Industry would rely heavily on real-time, remote, and unattended monitoring, as well as continuous data collection. Advanced reactor designs (e.g., Microreactors, SMR, etc.) intended for installation in remote and possibly inaccessible locations would require robust, compact, passive, low-cost, radiation-tolerant, and energy efficient sensor systems that could be remotely interrogated and provide real-time information of operating and safety-related parameters (temperature, flux, etc.). In addition, to ensure economic competitiveness and minimize sensor costs, it is equally important to guarantee a simple, streamlined, and cost-efficient manufacturing procedure. To achieve this, we explore the development of low-cost 3D-printed Surface Acoustic Wave (SAW) sensors optimized for remote monitoring of advanced reactors. SAW sensors are passive devices that can convert an electromagnetic wave into a surface acoustic wave propagating along a piezoelectric substrate. The mechanical wave is then reflected and eventually converted back into an electrical signal which can be broadcasted. These characteristics offer unique advantages including sensor simplicity, power-free operation, and radiation tolerance since no integrated circuits are needed. To develop customized SAW sensors, we used a state-of-the-art aerosol jet printer that enables precise fabrication of sensors with features as small as 10 μm. In this work, LiNbO3, LiTaO3 and Quartz substrates are used to demonstrate the feasibility of the proposed approach by 3D-printing two-port SAW structures using conductive silver nanoink. A parametric analysis is performed in order to optimize the printing procedure and investigate optimization of printing line resolution using optical and Scanning Electron Microscopy.
{"title":"3D-Printed SAW Sensor Development for Enabling Remote Monitoring of Advanced Reactors","authors":"Konstantinos Gkouliaras, Jake Marr, Vasileios Theos, S. Chatzidakis","doi":"10.1115/icone29-92008","DOIUrl":"https://doi.org/10.1115/icone29-92008","url":null,"abstract":"\u0000 Recent and future advancements in the upcoming digital era of Nuclear Industry would rely heavily on real-time, remote, and unattended monitoring, as well as continuous data collection. Advanced reactor designs (e.g., Microreactors, SMR, etc.) intended for installation in remote and possibly inaccessible locations would require robust, compact, passive, low-cost, radiation-tolerant, and energy efficient sensor systems that could be remotely interrogated and provide real-time information of operating and safety-related parameters (temperature, flux, etc.). In addition, to ensure economic competitiveness and minimize sensor costs, it is equally important to guarantee a simple, streamlined, and cost-efficient manufacturing procedure. To achieve this, we explore the development of low-cost 3D-printed Surface Acoustic Wave (SAW) sensors optimized for remote monitoring of advanced reactors.\u0000 SAW sensors are passive devices that can convert an electromagnetic wave into a surface acoustic wave propagating along a piezoelectric substrate. The mechanical wave is then reflected and eventually converted back into an electrical signal which can be broadcasted. These characteristics offer unique advantages including sensor simplicity, power-free operation, and radiation tolerance since no integrated circuits are needed. To develop customized SAW sensors, we used a state-of-the-art aerosol jet printer that enables precise fabrication of sensors with features as small as 10 μm. In this work, LiNbO3, LiTaO3 and Quartz substrates are used to demonstrate the feasibility of the proposed approach by 3D-printing two-port SAW structures using conductive silver nanoink. A parametric analysis is performed in order to optimize the printing procedure and investigate optimization of printing line resolution using optical and Scanning Electron Microscopy.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"7 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":"126175779","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}
Guangliang Yang, Weixiang Wang, Tao Ding, Hongli Chen
Thermal migration phenomena in the fast reactor can affect the temperature distribution and in-pile behaviors heavily through changing the local properties of nuclear fuels. In this research, the classical thermal diffusion equations for the oxygen diffusion, plutonium migration, Joint Oxide Gain (JOG) formation, and porosity migration are solved and integrated into the fuel rod performance analysis code KMC-Fueltra as thermal migration analysis module. Validations of these models have been performed by comparing with the experimental data or simulation results. Comparisons have proved the correctness of the thermal migration module in KMC-Fueltra. Effects of these phenomena to the fuel rod performance are analyzed and discussed under the steady-state operating conditions in the 1000MWth Medium-size Modular Lead-cooled Fast Reactor (M2LFR-1000) using multi-physics simulation of coupled thermal analysis, thermal migration analysis, fission gas release analysis and mechanical analysis. Simulation results show that the influence of thermal migration mainly reflects in the fuel pellet other than the cladding. It can result in large changes in some parameters during the evaluation of the fuel rod performance, compared with simulations that do not account for thermal migration phenomena.
快堆热迁移现象通过改变核燃料的局部性质，对堆内温度分布和堆内行为产生重大影响。在本研究中，求解了氧扩散、钚迁移、联合氧化增益(Joint Oxide Gain, JOG)形成和孔隙度迁移等经典热扩散方程，并将其作为热迁移分析模块集成到燃料棒性能分析程序KMC-Fueltra中。通过与实验数据或仿真结果的比较，对模型进行了验证。通过对比验证了KMC-Fueltra热迁移模块的正确性。采用耦合热分析、热迁移分析、裂变气体释放分析和力学分析等多物理场模拟方法，对1000mwm中型模块化铅冷快堆(M2LFR-1000)稳态工况下这些现象对燃料棒性能的影响进行了分析和讨论。模拟结果表明，热迁移的影响主要体现在燃料球团内部，而非包壳内部。与不考虑热迁移现象的模拟相比，在评估燃料棒性能时，它可能导致某些参数发生较大变化。
{"title":"Analysis on the Effects of Thermal Migration Phenomena to the Fuel Performance in the Fast Reactor","authors":"Guangliang Yang, Weixiang Wang, Tao Ding, Hongli Chen","doi":"10.1115/icone29-90561","DOIUrl":"https://doi.org/10.1115/icone29-90561","url":null,"abstract":"\u0000 Thermal migration phenomena in the fast reactor can affect the temperature distribution and in-pile behaviors heavily through changing the local properties of nuclear fuels. In this research, the classical thermal diffusion equations for the oxygen diffusion, plutonium migration, Joint Oxide Gain (JOG) formation, and porosity migration are solved and integrated into the fuel rod performance analysis code KMC-Fueltra as thermal migration analysis module. Validations of these models have been performed by comparing with the experimental data or simulation results. Comparisons have proved the correctness of the thermal migration module in KMC-Fueltra. Effects of these phenomena to the fuel rod performance are analyzed and discussed under the steady-state operating conditions in the 1000MWth Medium-size Modular Lead-cooled Fast Reactor (M2LFR-1000) using multi-physics simulation of coupled thermal analysis, thermal migration analysis, fission gas release analysis and mechanical analysis. Simulation results show that the influence of thermal migration mainly reflects in the fuel pellet other than the cladding. It can result in large changes in some parameters during the evaluation of the fuel rod performance, compared with simulations that do not account for thermal migration phenomena.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"72 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":"127334232","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}
Air dispersion modeling is an important tool for emergency response following a nuclear accident, such as the Fukushima accident. Current researches mainly focus on global- and regional-scale modeling with wind field data derived from different methodological models and observations. However, the capability of the local-scale atmospheric dispersion model hasn’t been discussed in detail for the Fukushima accident. In this paper, the local-scale modeling of radionuclides following the Fukushima accident was investigated with the combination of the wind diagnosed model SWIFT and the radionuclide transport model RIMPUFF. The coarse input wind field of SWIFT is prepared with WRF using the European Centre for Medium-Range Weather Forecasts (ECMWF) Meteorological data. The SWIFT-diagnosed wind field was used to drive RIMPUFF for calculating the dispersion of radionuclides and gamma dose rates around the Fukushima Daiichi Nuclear Power Plant (FDNPP) site. The diagnostic wind fields were validated to the on-site meteorological observations, whereas the dispersion and gamma dose rates were validated the onsite gamma dose rate monitoring data and the observations of suspended particulate m? near the FDNPP. The plume patterns were also analyzed to help understand the transport behaviour of the radionuclides. The validation demonstrates that, with the 1km-resolved ECMWF meteorological data, SWIFT fairly reproduces the wind field. The speed is slightly overestimated, with a Normalized Mean Squared Error (NMSE) below 6. The wind direction is well simulated at some specific moments, which is critical for reproducing some peaks of the dose rates. However, RIMPUFF underestimates the dose rates around the FDNPP, partly because of the overestimated wind speed. The concentration simulations better agree with observations in the Naraha station than Futaba station, with the Fractional Bias (FB) under 0.3 and NMSE under 6 at the Naraha station.
{"title":"Local-Scale Atmospheric Dispersion Modelling of Radionuclides Following the Fukushima Daiichi Nuclear Accident Using SWIFT-RIMPUFF","authors":"Shuhan Zhuang, Shengjiang Fang, Xinwen Dong","doi":"10.1115/icone29-90748","DOIUrl":"https://doi.org/10.1115/icone29-90748","url":null,"abstract":"\u0000 Air dispersion modeling is an important tool for emergency response following a nuclear accident, such as the Fukushima accident. Current researches mainly focus on global- and regional-scale modeling with wind field data derived from different methodological models and observations. However, the capability of the local-scale atmospheric dispersion model hasn’t been discussed in detail for the Fukushima accident. In this paper, the local-scale modeling of radionuclides following the Fukushima accident was investigated with the combination of the wind diagnosed model SWIFT and the radionuclide transport model RIMPUFF. The coarse input wind field of SWIFT is prepared with WRF using the European Centre for Medium-Range Weather Forecasts (ECMWF) Meteorological data. The SWIFT-diagnosed wind field was used to drive RIMPUFF for calculating the dispersion of radionuclides and gamma dose rates around the Fukushima Daiichi Nuclear Power Plant (FDNPP) site. The diagnostic wind fields were validated to the on-site meteorological observations, whereas the dispersion and gamma dose rates were validated the onsite gamma dose rate monitoring data and the observations of suspended particulate m? near the FDNPP. The plume patterns were also analyzed to help understand the transport behaviour of the radionuclides. The validation demonstrates that, with the 1km-resolved ECMWF meteorological data, SWIFT fairly reproduces the wind field. The speed is slightly overestimated, with a Normalized Mean Squared Error (NMSE) below 6. The wind direction is well simulated at some specific moments, which is critical for reproducing some peaks of the dose rates. However, RIMPUFF underestimates the dose rates around the FDNPP, partly because of the overestimated wind speed. The concentration simulations better agree with observations in the Naraha station than Futaba station, with the Fractional Bias (FB) under 0.3 and NMSE under 6 at the Naraha station.","PeriodicalId":302303,"journal":{"name":"Volume 15: Student Paper Competition","volume":"22 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":"127439024","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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