Pub Date : 2024-07-31DOI: 10.1016/j.net.2024.07.058
Kyungha Ryu, Seonggyu Cho, Taeho Roh, Sangkyo Kim, Taekook Park, Taehyun Lee, Jongwon Park, Jaehyun Cho
The present study focuses on the development of an equipment qualification (EQ) testing facility for Class 1E equipment in nuclear power plants (NPPs), emphasizing the need to ensure safety functions under design basis events (DBEs). The Republic of Korea (ROK) has implemented international safety standards to support large NPP projects, necessitating the development of domestic EQ testing facilities to reduce the dependence on foreign facilities. To address this need, herein, a specialized facility capable of simulating harsh DBE conditions that may occur in NPPs in ROK was constructed. Through exhaustive research, target temperature and pressure profiles were developed for pressurized water reactors, and a superheated steam injection technique was devised for rapid temperature and pressure changes. The present study contributes to the advancement of domestic EQ testing capabilities, achieving up to 230 °C and 700 kPa within 30 s.
本研究的重点是开发核电站 1E 级设备的设备鉴定（EQ）测试设施，强调在设计基础事件（DBE）下确保安全功能的必要性。大韩民国（ROK）已实施国际安全标准来支持大型 NPP 项目，因此有必要开发国内 EQ 测试设施，以减少对国外设施的依赖。为了满足这一需求，我们在此建造了一个能够模拟韩国核电站中可能出现的恶劣 DBE 条件的专门设施。通过详尽的研究，为压水反应堆开发了目标温度和压力曲线，并设计了过热蒸汽喷射技术，以实现快速的温度和压力变化。本研究有助于提高国内 EQ 测试能力，在 30 秒内达到 230 °C 和 700 kPa。
{"title":"Enhancing equipment qualification testing facility for nuclear power plants: Achieving rapid temperature and pressure increase during design basis events","authors":"Kyungha Ryu, Seonggyu Cho, Taeho Roh, Sangkyo Kim, Taekook Park, Taehyun Lee, Jongwon Park, Jaehyun Cho","doi":"10.1016/j.net.2024.07.058","DOIUrl":"https://doi.org/10.1016/j.net.2024.07.058","url":null,"abstract":"The present study focuses on the development of an equipment qualification (EQ) testing facility for Class 1E equipment in nuclear power plants (NPPs), emphasizing the need to ensure safety functions under design basis events (DBEs). The Republic of Korea (ROK) has implemented international safety standards to support large NPP projects, necessitating the development of domestic EQ testing facilities to reduce the dependence on foreign facilities. To address this need, herein, a specialized facility capable of simulating harsh DBE conditions that may occur in NPPs in ROK was constructed. Through exhaustive research, target temperature and pressure profiles were developed for pressurized water reactors, and a superheated steam injection technique was devised for rapid temperature and pressure changes. The present study contributes to the advancement of domestic EQ testing capabilities, achieving up to 230 °C and 700 kPa within 30 s.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During the in-situ leaching process of sandstone uranium ore deposits, the dynamic evolution of reactive transport parameters, including permeability, tortuosity, and specific surface area (SSA), plays a crucial role in solution flow and solute transport. Characterizing the evolution of these parameters is essential for understanding the leaching process. However, the heterogeneous pore structure of sandstone renders porosity alone insufficient to capture changes in these parameters. This study combines porosity and lacunarity to comprehensively characterize these parameters. For this purpose, leaching experiments were conducted on sandstone uranium ore samples, and CT imaging was performed at different leaching time points. The evolution of reactive transport parameters was analyzed by studying cubic subsamples from the images. The results indicate that both porosity and lacunarity are significant factors influencing the reactive transport parameters. However, neither parameter alone adequately characterizes their evolution. In contrast, combining them accurately characterizes the evolution of reactive transport parameters. Porosity reflects pore quantity, while lacunarity represents pore heterogeneity. Combining these measures facilitates a comprehensive understanding of the evolution of reactive transport parameters and the influence of pore microstructure on macroscopic reactive transport parameters. This research provides valuable insights for optimizing the leaching process in sandstone uranium ore deposits.
{"title":"Characterization of evolution of reactive transport parameters during leaching process of sandstone uranium ore by combining porosity and lacunarity","authors":"Haiying Fu, Shuai Wang, Deming Tan, Guicheng He, Meng Lian, Zhonghua Zhu, Dexin Ding","doi":"10.1016/j.net.2024.07.057","DOIUrl":"https://doi.org/10.1016/j.net.2024.07.057","url":null,"abstract":"During the in-situ leaching process of sandstone uranium ore deposits, the dynamic evolution of reactive transport parameters, including permeability, tortuosity, and specific surface area (SSA), plays a crucial role in solution flow and solute transport. Characterizing the evolution of these parameters is essential for understanding the leaching process. However, the heterogeneous pore structure of sandstone renders porosity alone insufficient to capture changes in these parameters. This study combines porosity and lacunarity to comprehensively characterize these parameters. For this purpose, leaching experiments were conducted on sandstone uranium ore samples, and CT imaging was performed at different leaching time points. The evolution of reactive transport parameters was analyzed by studying cubic subsamples from the images. The results indicate that both porosity and lacunarity are significant factors influencing the reactive transport parameters. However, neither parameter alone adequately characterizes their evolution. In contrast, combining them accurately characterizes the evolution of reactive transport parameters. Porosity reflects pore quantity, while lacunarity represents pore heterogeneity. Combining these measures facilitates a comprehensive understanding of the evolution of reactive transport parameters and the influence of pore microstructure on macroscopic reactive transport parameters. This research provides valuable insights for optimizing the leaching process in sandstone uranium ore deposits.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141940111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.1016/j.net.2024.07.059
Eunjung Cho, Juyong Lee
This study provides a comprehensive analysis of the social acceptance of the Small Modular Reactor (SMR) in South Korea. The growing interest in SMRs as a potential solution to the challenges of climate change and energy security highlights the need for continued research and development in this area. The research was conducted using a contingent valuation method, which involved surveying a representative sample of the South Korean population. Out of a total of 1032 respondents, 78 % were willing to pay for SMR development. The mean WTP was estimated to be USD 4.28 per year per household and scaled up to the national level in South Korea, it was analysed to have a total economic and social benefit of USD 0.49 billion. The more serious the respondents perceived the current and future problem of climate change to be, the more likely they were to be willing to pay an offered bid amount. This study suggests that the need to address climate change and the need to raise awareness of SMR as one of the low-carbon technologies at the government level is required to generate the appropriate level of social acceptance to promote SMR development.
{"title":"Social acceptance of small modular reactor (SMR): Evidence from a contingent valuation study in South Korea","authors":"Eunjung Cho, Juyong Lee","doi":"10.1016/j.net.2024.07.059","DOIUrl":"https://doi.org/10.1016/j.net.2024.07.059","url":null,"abstract":"This study provides a comprehensive analysis of the social acceptance of the Small Modular Reactor (SMR) in South Korea. The growing interest in SMRs as a potential solution to the challenges of climate change and energy security highlights the need for continued research and development in this area. The research was conducted using a contingent valuation method, which involved surveying a representative sample of the South Korean population. Out of a total of 1032 respondents, 78 % were willing to pay for SMR development. The mean WTP was estimated to be USD 4.28 per year per household and scaled up to the national level in South Korea, it was analysed to have a total economic and social benefit of USD 0.49 billion. The more serious the respondents perceived the current and future problem of climate change to be, the more likely they were to be willing to pay an offered bid amount. This study suggests that the need to address climate change and the need to raise awareness of SMR as one of the low-carbon technologies at the government level is required to generate the appropriate level of social acceptance to promote SMR development.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141940107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-25DOI: 10.1016/j.net.2024.07.039
This study investigates the effects of Zinc (Zn), Manganese (Mn), and Iron (Fe) additions on the microstructure, corrosion behaviour, biocompatibility, mechanical, and gamma-ray shielding properties of Magnesium (Mg) alloys prepared in various compositions using powder metallurgy (PM). The microstructure and mechanical properties of these alloys were analyzed using electron microscopes (SEM and FE-SEM) and X-ray diffraction (XRD) methods. The results showed positive changes in the material's structure when the percentage of zinc added to pure magnesium increased. It was observed that the material became ductile, and the ductile fracture increased when the zinc ratio increased. The gamma-ray shielding properties of newly produced Mg-based alloys have also been discussed since they have a high potential for use in space technologies. Radiation shielding measurements have been performed using a 3′′ × 3″ NaI(Tl) scintillation detector NaI (Tl) gamma-ray spectrometer. The gamma-ray shielding parameters such as the linear attenuation coefficients (μl), mass attenuation coefficient (μm), effective atomic number (Zeff), half-value layer (HVL), and tenth-value layer (TVL) have been determined experimentally at photon energies of 0.511 MeV (emitted from a22Na radioactive point source) and 1.173 MeV and 1.332 MeV (emitting from a60Co radioactive point source). The obtained parameters have been compared to the theoretical results of the XCOM software, and a satisfactory agreement has been found. It can be said from the results that the Mg30Zn alloy has the best shielding properties among the produced materials.
{"title":"The effect of zinc, iron and manganese content on gamma shielding properties of magnesium-based alloys produced using the powder metallurgy","authors":"","doi":"10.1016/j.net.2024.07.039","DOIUrl":"10.1016/j.net.2024.07.039","url":null,"abstract":"<div><p>This study investigates the effects of Zinc (Zn), Manganese (Mn), and Iron (Fe) additions on the microstructure, corrosion behaviour, biocompatibility, mechanical, and gamma-ray shielding properties of Magnesium (Mg) alloys prepared in various compositions using powder metallurgy (PM). The microstructure and mechanical properties of these alloys were analyzed using electron microscopes (SEM and FE-SEM) and X-ray diffraction (XRD) methods. The results showed positive changes in the material's structure when the percentage of zinc added to pure magnesium increased. It was observed that the material became ductile, and the ductile fracture increased when the zinc ratio increased. The gamma-ray shielding properties of newly produced Mg-based alloys have also been discussed since they have a high potential for use in space technologies. Radiation shielding measurements have been performed using a 3′′ × 3″ NaI(Tl) scintillation detector NaI (Tl) gamma-ray spectrometer. The gamma-ray shielding parameters such as the linear attenuation coefficients (<em>μ</em><sub><em>l</em></sub>), mass attenuation coefficient (<em>μ</em><sub><em>m</em></sub>), effective atomic number (<em>Z</em><sub><em>eff</em></sub>), half-value layer (HVL), and tenth-value layer (TVL) have been determined experimentally at photon energies of 0.511 MeV (emitted from a<sup>22</sup>Na radioactive point source) and 1.173 MeV and 1.332 MeV (emitting from a<sup>60</sup>Co radioactive point source). The obtained parameters have been compared to the theoretical results of the XCOM software, and a satisfactory agreement has been found. It can be said from the results that the Mg30Zn alloy has the best shielding properties among the produced materials.</p></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1738573324003553/pdfft?md5=128052f229f67b813b02811a9379a697&pid=1-s2.0-S1738573324003553-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141840766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1016/j.net.2024.07.050
Peter J. Hiller MSc BSc, Caroline K. Pyke MSc BSc, Chris P. Lennon BSc, Olivia C.G. Tuck MMathStat, Caitlin A. Painter BSc
The disposal of radioactive waste within the UK is managed through a comprehensive regulatory framework. This framework requires radioactive waste to be sufficiently well characterized to ensure its disposal is compliant with the regulations and the acceptance criteria for any receiving facility. This is the responsibility of both the waste consignor and the receiving facility.
{"title":"The ability to manage uncertainty for solid radioactive waste characterization in the UK nuclear industry","authors":"Peter J. Hiller MSc BSc, Caroline K. Pyke MSc BSc, Chris P. Lennon BSc, Olivia C.G. Tuck MMathStat, Caitlin A. Painter BSc","doi":"10.1016/j.net.2024.07.050","DOIUrl":"https://doi.org/10.1016/j.net.2024.07.050","url":null,"abstract":"The disposal of radioactive waste within the UK is managed through a comprehensive regulatory framework. This framework requires radioactive waste to be sufficiently well characterized to ensure its disposal is compliant with the regulations and the acceptance criteria for any receiving facility. This is the responsibility of both the waste consignor and the receiving facility.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1016/j.net.2024.07.051
Longxian Li, Min Zhu, Yan Li, Yanru Ren, Longfei Pu, Chengxuan Peng
A first-principles approach based on density-functional theory has been used to investigate the corrosion resistance of alpha-U in the CO environment. Calculations show that O molecules spontaneously dissociate on the uranium surface, and the two O atoms formed by dissociation tend to adsorb on the hole sites and bind to the surface in the form of a U-O bond to emit a large amount of heat. The CO molecules occur on the surface of uranium as a non-dissociative chemical. The mechanism of CO inhibiting the adsorption of O molecules stems from the fact that CO molecules occupy the optimal adsorption sites. Another inhibition mechanism, the combination of C atoms and O atoms to form bonds and consume oxygen atoms, has little effect on uranium corrosion.
我们采用基于密度泛函理论的第一原理方法研究了α-U 在 CO 环境中的耐腐蚀性。计算表明，O 分子在铀表面自发解离，解离形成的两个 O 原子倾向于吸附在空穴位点上，并以 U-O 键的形式与表面结合，从而释放出大量热量。CO 分子作为一种非解离化学物质出现在铀表面。CO 抑制 O 分子吸附的机制源于 CO 分子占据了最佳吸附位点。另一种抑制机制，即 C 原子和 O 原子结合成键并消耗氧原子，对铀腐蚀的影响很小。
{"title":"The role of CO on initial oxidation behavior of α-U(001) surface: a first principles study","authors":"Longxian Li, Min Zhu, Yan Li, Yanru Ren, Longfei Pu, Chengxuan Peng","doi":"10.1016/j.net.2024.07.051","DOIUrl":"https://doi.org/10.1016/j.net.2024.07.051","url":null,"abstract":"A first-principles approach based on density-functional theory has been used to investigate the corrosion resistance of alpha-U in the CO environment. Calculations show that O molecules spontaneously dissociate on the uranium surface, and the two O atoms formed by dissociation tend to adsorb on the hole sites and bind to the surface in the form of a U-O bond to emit a large amount of heat. The CO molecules occur on the surface of uranium as a non-dissociative chemical. The mechanism of CO inhibiting the adsorption of O molecules stems from the fact that CO molecules occupy the optimal adsorption sites. Another inhibition mechanism, the combination of C atoms and O atoms to form bonds and consume oxygen atoms, has little effect on uranium corrosion.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-23DOI: 10.1016/j.net.2024.07.047
Sung-Wook Kim, Hee-Man Yang, Hyung-Ju Kim
Surface decontamination agents must effectively capture particle contaminants that have been deposited on surfaces. This ability is particularly important in scenarios involving nuclear fallout particles. In this technical note, the particle-capturing ability of a hydrogel, specifically, the polyvinyl alcohol-borax complex, was investigated as a potential decontamination agent for treating radioactively contaminated surface. For the assessment, simulated nuclear fallout particles, prepared by melting consolidation at 1200 °C followed by mechanical milling, were fixed on a stainless-steel substrate. The results demonstrated that the hydrogel effectively removed the simulated fallout particles from the surface. Even after only 1 min of contact time, the surface was left thoroughly clean, demonstrating the effectiveness of the polyvinyl alcohol-borax complex as a surface decontamination agent.
表面去污剂必须能有效捕捉沉积在表面上的颗粒污染物。在涉及核尘埃粒子的情况下，这种能力尤为重要。在本技术说明中，研究了水凝胶（特别是聚乙烯醇-硼砂复合物）作为潜在去污剂处理放射性污染表面的粒子捕获能力。为了进行评估，在不锈钢基底上固定了通过 1200 °C 熔化固结和机械研磨制备的模拟核尘埃粒子。结果表明，水凝胶能有效去除表面的模拟核沉降物颗粒。即使只接触了 1 分钟，表面也被彻底清洁，这证明了聚乙烯醇-硼砂复合物作为表面去污剂的有效性。
{"title":"Evaluation of particle-capturing ability of a hydrogel-based surface decontamination agent using simulated nuclear fallout particles","authors":"Sung-Wook Kim, Hee-Man Yang, Hyung-Ju Kim","doi":"10.1016/j.net.2024.07.047","DOIUrl":"https://doi.org/10.1016/j.net.2024.07.047","url":null,"abstract":"Surface decontamination agents must effectively capture particle contaminants that have been deposited on surfaces. This ability is particularly important in scenarios involving nuclear fallout particles. In this technical note, the particle-capturing ability of a hydrogel, specifically, the polyvinyl alcohol-borax complex, was investigated as a potential decontamination agent for treating radioactively contaminated surface. For the assessment, simulated nuclear fallout particles, prepared by melting consolidation at 1200 °C followed by mechanical milling, were fixed on a stainless-steel substrate. The results demonstrated that the hydrogel effectively removed the simulated fallout particles from the surface. Even after only 1 min of contact time, the surface was left thoroughly clean, demonstrating the effectiveness of the polyvinyl alcohol-borax complex as a surface decontamination agent.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-23DOI: 10.1016/j.net.2024.07.049
Hyungi Byun, Han Gil Lee, Beom Kyu Kim, Geun Dong Song, Bongsoo Lee
This study developed a defect-monitoring system with an artificial intelligence model, YOLOv7, which is tailored for processing image data from an ultrasonic visualization system within sodium fast reactor (SFR) internal structures. For the safety of SFR internal structures, although it is a crucial inspection for defect monitoring, it is difficult to identify structural defects because of the invisible environment. Therefore, we applied the YOLOv7 model in this study; however, we encountered challenges including decreased accuracy with complex defect shapes and complications from data augmentation during pre-training. To solve these problems, we additionally applied the enhanced super-resolution generative adversarial network for higher resolution and a Sobel noise-filtering algorithm to enhance the defect detection accuracy. And we evaluated our system by comparing it with a confidence score. This underscores the effectiveness of the approach in enhancing the defect detection capabilities. Therefore, this defect-monitoring system should be designed to preemptively identify internal structure deformations and enhance SFR safety and maintenance practices.
{"title":"Defect Monitoring System of the Internal Structures of a Sodium Fast Reactor using an Artificial Intelligence Model","authors":"Hyungi Byun, Han Gil Lee, Beom Kyu Kim, Geun Dong Song, Bongsoo Lee","doi":"10.1016/j.net.2024.07.049","DOIUrl":"https://doi.org/10.1016/j.net.2024.07.049","url":null,"abstract":"This study developed a defect-monitoring system with an artificial intelligence model, YOLOv7, which is tailored for processing image data from an ultrasonic visualization system within sodium fast reactor (SFR) internal structures. For the safety of SFR internal structures, although it is a crucial inspection for defect monitoring, it is difficult to identify structural defects because of the invisible environment. Therefore, we applied the YOLOv7 model in this study; however, we encountered challenges including decreased accuracy with complex defect shapes and complications from data augmentation during pre-training. To solve these problems, we additionally applied the enhanced super-resolution generative adversarial network for higher resolution and a Sobel noise-filtering algorithm to enhance the defect detection accuracy. And we evaluated our system by comparing it with a confidence score. This underscores the effectiveness of the approach in enhancing the defect detection capabilities. Therefore, this defect-monitoring system should be designed to preemptively identify internal structure deformations and enhance SFR safety and maintenance practices.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-23DOI: 10.1016/j.net.2024.07.045
Xicheng Wang, Govatsa Acharya, Dmitry Grishchenko, Pavel Kudinov
Boiling Water Reactor (BWR) employs the Pressure Suppression Pool (PSP) as a heat sink to prevent overpressure of the reactor vessel and containment. Steam can be injected into the PSP through spargers in normal and accident conditions and through blowdown pipes in case of a loss of coolant accident (LOCA). There is a safety limit on the maximum PSP temperature at which such steam injection might cause dynamic loads on the containment structures. The performance of the pool can be affected if thermal stratification is developed when temperature of the hot layer grows rapidly while cold layer remains inactive. Simulation of pool behavior during realistic accident scenarios requires validated models that can sufficiently address the interaction between phenomena, safety systems and operational procedures. Direct modeling of steam injection into a water pool in long-term transients is computationally expensive due to the need to resolve simultaneously the smallest space and time scales of individual steam bubbles and the scales of the whole PSP. To enable PSP analysis for practical purposes, Effective Heat source and Effective Momentum source (EHS/EMS) models have been proposed that avoid the need to resolve steam-water interface. This paper aims to implement mechanistic approaches previously developed by authors for the simulation of transient thermal stratification and mixing phenomena induced by steam injection through spargers in a Nordic BWR PSP. The latest version of the EHS/EMS models using the ‘Unit cell’ approach has been validated against integral effect pool tests and applied to plant simulations. Several scenarios with boundary conditions corresponding to postulated accident sequences were simulated to investigate the possibility of stratification development and the effects of activation of different systems (e.g., blowdown pipes, high momentum nozzle) on the pool behavior.
{"title":"CFD Simulation of Thermal Stratification and Mixing in a Nordic BWR Pressure Suppression Pool","authors":"Xicheng Wang, Govatsa Acharya, Dmitry Grishchenko, Pavel Kudinov","doi":"10.1016/j.net.2024.07.045","DOIUrl":"https://doi.org/10.1016/j.net.2024.07.045","url":null,"abstract":"Boiling Water Reactor (BWR) employs the Pressure Suppression Pool (PSP) as a heat sink to prevent overpressure of the reactor vessel and containment. Steam can be injected into the PSP through spargers in normal and accident conditions and through blowdown pipes in case of a loss of coolant accident (LOCA). There is a safety limit on the maximum PSP temperature at which such steam injection might cause dynamic loads on the containment structures. The performance of the pool can be affected if thermal stratification is developed when temperature of the hot layer grows rapidly while cold layer remains inactive. Simulation of pool behavior during realistic accident scenarios requires validated models that can sufficiently address the interaction between phenomena, safety systems and operational procedures. Direct modeling of steam injection into a water pool in long-term transients is computationally expensive due to the need to resolve simultaneously the smallest space and time scales of individual steam bubbles and the scales of the whole PSP. To enable PSP analysis for practical purposes, Effective Heat source and Effective Momentum source (EHS/EMS) models have been proposed that avoid the need to resolve steam-water interface. This paper aims to implement mechanistic approaches previously developed by authors for the simulation of transient thermal stratification and mixing phenomena induced by steam injection through spargers in a Nordic BWR PSP. The latest version of the EHS/EMS models using the ‘Unit cell’ approach has been validated against integral effect pool tests and applied to plant simulations. Several scenarios with boundary conditions corresponding to postulated accident sequences were simulated to investigate the possibility of stratification development and the effects of activation of different systems (e.g., blowdown pipes, high momentum nozzle) on the pool behavior.","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-22DOI: 10.1016/j.net.2024.07.044
Rashed MD. Sardar, Akhmed M. Baisov
The evaluation of available Look-Up Tables for prediction of heat transfer coefficient distribution in rod bundles cooled by supercritical water with the aim of their further use in computational analyses of various Fuel Assembles of Supercritical Water-Cooled Reactors is made. The comparison between the calculations based on Look-Up Tables with the values from empirical correlations and experimental data for smooth and wire-wrapped rod bundles was presented. The obtained results showed that Look-Up Table of the University of Ottawa, which was created to describe improved and deteriorated heat transfer regimes in round tubes, allows describing available data points with 30% of the mean square deviation. It is noted that the presence of wire intensifies heat transfer exchange near pseudocritical temperature region but existing versions of Look-Up Tables cannot take into account this effect. Nevertheless, there is potential for further improvement in predicting the heat transfer coefficient using Look-Up Table by introducing additional correction factors.
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