Journal of Nuclear Engineering最新文献

Validation of the SCALE/Polaris−PARCS Code Procedure with the ENDF/B-VII.1 AMPX 56-Group Library: Pressurized Water Reactor 利用ENDF/B-VII.1 AMPX 56组库验证SCALE/Polaris-PARCS代码程序：压水堆

Journal of Nuclear Engineering Pub Date : 2024-07-23 DOI: 10.3390/jne5030017

Kang Kim, Byoung-kyu Jeon, Andrew Ward, U. Mertyurek, Matthew Jessee, W. Wieselquist

引用次数: 0

Phenomenological Nondimensional Parameter Decomposition to Enhance the Use of Simulation Modeling in Fire Probabilistic Risk Assessment of Nuclear Power Plants 在核电站火灾概率风险评估中加强使用仿真建模的现象学二维参数分解法

Journal of Nuclear Engineering Pub Date : 2024-07-02 DOI: 10.3390/jne5030016

Sari F. Alkhatib, T. Sakurahara, S. Reihani, Ernest Kee, Brian Ratte, Kristin Kaspar, Sean Hunt, Z. Mohaghegh

{"title":"Phenomenological Nondimensional Parameter Decomposition to Enhance the Use of Simulation Modeling in Fire Probabilistic Risk Assessment of Nuclear Power Plants","authors":"Sari F. Alkhatib, T. Sakurahara, S. Reihani, Ernest Kee, Brian Ratte, Kristin Kaspar, Sean Hunt, Z. Mohaghegh","doi":"10.3390/jne5030016","DOIUrl":"https://doi.org/10.3390/jne5030016","url":null,"abstract":"Simulation modeling is crucial in support of probabilistic risk assessment (PRA) for nuclear power plants (NPPs). There is a challenge, however, associated with simulation modeling that relates to the time and resources required for collecting data to determine the values of the input parameters. To alleviate this challenge, this article develops a formalized methodology to generate surrogate values of input parameters grounded on the decomposition of phenomenological nondimensional parameters (PNPs) while avoiding detailed data collection. While the fundamental principles of the proposed methodology can be applicable to various hazards, the developments in this article focus on fire PRA as an example application area for which resource intensiveness is recognized as a practical challenge. This article also develops a computational platform to automate the PNP decomposition and seamlessly integrates it with state-of-practice fire scenario analysis. The applicability of the computational platform is demonstrated through a multi-compartment fire case study at an NPP. The computational platform, with its embedded PNP decomposition methodology, can substantially reduce the effort required for input data collection and extraction, thereby facilitating the efficient use of simulation modeling in PRA and enhancing the fire scenario screening analysis.","PeriodicalId":512967,"journal":{"name":"Journal of Nuclear Engineering","volume":"54 s57","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141688335","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}

引用次数: 0

Reinforcement Learning-Based Control Sequence Optimization for Advanced Reactors 基于强化学习的先进反应堆控制顺序优化

Journal of Nuclear Engineering Pub Date : 2024-07-01 DOI: 10.3390/jne5030015

Khang H. N. Nguyen, Andy Rivas, G. Delipei, Jason Hou

{"title":"Reinforcement Learning-Based Control Sequence Optimization for Advanced Reactors","authors":"Khang H. N. Nguyen, Andy Rivas, G. Delipei, Jason Hou","doi":"10.3390/jne5030015","DOIUrl":"https://doi.org/10.3390/jne5030015","url":null,"abstract":"The last decade has seen the development and application of data-driven methods taking off in nuclear engineering research, aiming to improve the safety and reliability of nuclear power. This work focuses on developing a reinforcement learning-based control sequence optimization framework for advanced nuclear systems, which not only aims to enhance flexible operations, promoting the economics of advanced nuclear technology, but also prioritizing safety during normal operation. At its core, the framework allows the sequence of operational actions to be learned and optimized by an agent to facilitate smooth transitions between the modes of operations (i.e., load-following), while ensuring that all safety significant system parameters remain within their respective limits. To generate dynamic system responses, facilitate control strategy development, and demonstrate the effectiveness of the framework, a simulation environment of a pebble-bed high-temperature gas-cooled reactor was utilized. The soft actor-critic algorithm was adopted to train a reinforcement learning agent, which can generate control sequences to maneuver plant power output in the range between 100% and 50% of the nameplate power through sufficient training. It was shown in the performance validation that the agent successfully generated control actions that maintained electrical output within a tight tolerance of 0.5% from the demand while satisfying all safety constraints. During the mode transition, the agent can maintain the reactor outlet temperature within ±1.5 °C and steam pressure within 0.1 MPa of their setpoints, respectively, by dynamically adjusting control rod positions, control valve openings, and pump speeds. The results demonstrate the effectiveness of the optimization framework and the feasibility of reinforcement learning in designing control strategies for advanced reactor systems.","PeriodicalId":512967,"journal":{"name":"Journal of Nuclear Engineering","volume":"40 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141716458","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}

引用次数: 0

Core Optimization for Extending the Graphite Irradiation Lifespan in a Small Modular Thorium-Based Molten Salt Reactor 优化堆芯以延长小型模块化钍基熔盐反应堆的石墨辐照寿命

Journal of Nuclear Engineering Pub Date : 2024-05-10 DOI: 10.3390/jne5020012

Xuzhong Kang, Guifeng Zhu, Jianhui Wu, Rui Yan, Yang Zou, Yafen Liu

{"title":"Core Optimization for Extending the Graphite Irradiation Lifespan in a Small Modular Thorium-Based Molten Salt Reactor","authors":"Xuzhong Kang, Guifeng Zhu, Jianhui Wu, Rui Yan, Yang Zou, Yafen Liu","doi":"10.3390/jne5020012","DOIUrl":"https://doi.org/10.3390/jne5020012","url":null,"abstract":"The lifespan of core graphite under neutron irradiation in a commercial molten salt reactor (MSR) has an important influence on its economy. Flattening the fast neutron flux (≥0.05 MeV) distribution in the core is the main method to extend the graphite irradiation lifespan. In this paper, the effects of the key parameters of MSRs on fast neutron flux distribution, including volume fraction (VF) of fuel salt, pitch of hexagonal fuel assembly, core zoning, and layout of control rod assemblies, were studied. The fast neutron flux distribution in a regular hexagon fuel assembly was first analyzed by varying VF and pitch. It was demonstrated that changing VF is more effective in reducing the fast neutron flux in both global and local graphite blocks. Flattening the fast neutron flux distribution of a commercial MSR core was then carried out by zoning the core into two regions under different VFs. Considering both the fast neutron flux distribution and burnup depth, an optimized core was obtained. The fast neutron flux distribution of the optimized core was further flattened by the rational arrangement of control rod channels. The calculation results show that the final optimized core could reduce the maximum fast neutron flux of the graphite blocks by about 30% and result in a more negative temperature reactivity coefficient, while slightly decreasing the burnup and maintaining a fully acceptable core temperature distribution.","PeriodicalId":512967,"journal":{"name":"Journal of Nuclear Engineering","volume":" 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140991737","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}

引用次数: 0

The Effects of Irradiation on Structure and Leaching of Pure and Doped Thin-Film Ceria SIMFUEL Models Prepared via Polymer-Templated Deposition 辐照对通过聚合物沉积制备的纯铈和掺杂铈薄膜 SIMFUEL 模型的结构和浸出的影响

Journal of Nuclear Engineering Pub Date : 2024-05-08 DOI: 10.3390/jne5020011

Alistair F. Holdsworth, Zizhen Feng, Ruth Edge, John P. Waters, Alice M. Halman, David Collison, Kathryn George, L. Natrajan, Melissa A. Denecke

{"title":"The Effects of Irradiation on Structure and Leaching of Pure and Doped Thin-Film Ceria SIMFUEL Models Prepared via Polymer-Templated Deposition","authors":"Alistair F. Holdsworth, Zizhen Feng, Ruth Edge, John P. Waters, Alice M. Halman, David Collison, Kathryn George, L. Natrajan, Melissa A. Denecke","doi":"10.3390/jne5020011","DOIUrl":"https://doi.org/10.3390/jne5020011","url":null,"abstract":"When studying hazardous materials such as spent nuclear fuel (SNF), the minimisation of sample volumes is essential, together with the use of chemically-similar surrogates where possible. For example, the bulk behaviour of urania (UO2) can be mimicked by appropriately-engineered thin films of sufficient thickness, and inactive materials such as ceria (CeO2) can be used to study the effects within radioactive systems used to fuel nuclear fission. However, thin film properties are sensitive to the preparative method, many of which require the use of highly toxic precursors and specialised apparatus (e.g., chemical vapour deposition). To address this, we present the development of a flexible, tuneable, scalable method for the preparation of thin-film CeO2 SIMFUEL models with a thickness of ≈5 μm. The effects of γ irradiation (up to 100 kGy) and dopants including trivalent lanthanides (Ln3+) and simulant ε-particles on the structure and long-term leaching of these systems under SNF storage conditions were explored, alongside the context of this within further work. It was found that the sensitivity of CeO2 films to reduction upon irradiation, particularly in the presence of simulant ε-particles, resulted in increased leaching of Ce (as CeIII), while trivalent lanthanides (Nd3+ and Eu3+) had a minimal effect on Ce leaching.","PeriodicalId":512967,"journal":{"name":"Journal of Nuclear Engineering","volume":" 48","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140998139","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}

引用次数: 0

Numerical Investigation of Butterfly Valve Performance in Variable Valve Sizes, Positions and Flow Regimes 不同阀门尺寸、位置和流态下蝶阀性能的数值研究

Journal of Nuclear Engineering Pub Date : 2024-04-24 DOI: 10.3390/jne5020010

Anutam Bairagi, Mingfu He, Minghui Chen

{"title":"Numerical Investigation of Butterfly Valve Performance in Variable Valve Sizes, Positions and Flow Regimes","authors":"Anutam Bairagi, Mingfu He, Minghui Chen","doi":"10.3390/jne5020010","DOIUrl":"https://doi.org/10.3390/jne5020010","url":null,"abstract":"Reliability and efficiency of valves are necessary for precise control and sufficient heat-flow to heat application plants for the integrated energy systems of nuclear power plants (NPPs). Strategic Management Analysis Requirement and Technology (SMART) valves’ ability to control flow and assess environmental parameters stands out for these requirements. Their ability to sustain the downstream flow rate, prevent reverse flow, and maintain pressure in the heat transport loop is much more efficient with the integration of sensors and intelligent algorithms. For assessing valve performance and monitoring, mechanical design and operating conditions are two important parameters. In this study, the butterfly valves of three different sizes are simulated with water and steam using STAR-CCM+ in various flow regimes and positions to analyze performance parameters to strategize an automated control system for efficiently balancing the heat–transport network. Also, flow behavior is studied using velocity and pressure fields for valve–body geometry optimization. It can be observed, through performance parameters, that the valves are suitable for operation between 30° and 90° positions with significantly low loss coefficients and high flow coefficients, and the performance parameters follow a certain pattern in both water and steam flow in each scenario.","PeriodicalId":512967,"journal":{"name":"Journal of Nuclear Engineering","volume":"79 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140665507","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}

引用次数: 0

Correction: Chakin et al. Tritium Desorption Behavior and Microstructure Evolution of Beryllium Irradiated at Low Temperature Up to High Neutron Dose in BR2 Reactor. J. Nucl. Eng. 2023, 4, 552–564 更正：Chakin 等人. BR2 反应堆中低温至高中子剂量辐照铍的氚解吸行为和微结构演变.J. Nucl.2023, 4, 552-564

Journal of Nuclear Engineering Pub Date : 2024-03-08 DOI: 10.3390/jne5010008

V. Chakin, Rolf Rolli, Ramil Gaisin, Wouter van Renterghem

引用次数: 0

Design and Application of DG-FEM Basis Functions for Neutron Transport on Two-Dimensional and Three-Dimensional Hexagonal Meshes 二维和三维六边形网格上中子输运 DG-FEM 基本函数的设计与应用

Journal of Nuclear Engineering Pub Date : 2024-02-26 DOI: 10.3390/jne5010006

A. Calloo, D. Labeurthre, R. Le Tellier

{"title":"Design and Application of DG-FEM Basis Functions for Neutron Transport on Two-Dimensional and Three-Dimensional Hexagonal Meshes","authors":"A. Calloo, D. Labeurthre, R. Le Tellier","doi":"10.3390/jne5010006","DOIUrl":"https://doi.org/10.3390/jne5010006","url":null,"abstract":"Reactor design requires safety studies to ensure that the reactors will behave appropriately under incidental or accidental situations. Safety studies often involve multiphysics simulations where several branches of reactor physics are necessary to model a given phenomenon. In those situations, it has been observed that the neutron transport part is still a bottleneck in terms of computational times, with more than 80% of the total time. In the case of hexagonal lattice reactors, transport solvers usually invert the discretised Boltzmann equation by discretising the regular hexagon into lozenges or triangles. In this work, we seek to reduce the computational burden of the neutron transport solver by designing a numerical spatial discretisation scheme that would be more appropriate for honeycomb meshes. In our past research efforts, we have set up interesting discretisation schemes in the finite element setting in 2D, and we wish to extend them to 3D geometries that are prisms with a hexagonal base. In 3D, a rigorous method was derived to shrink the tensor product between 2D and 1D bases to minimum terms. We have applied these functions successfully on a reactor benchmark—Takeda Model 4—to compare and contrast the numerical results in a physical setting.","PeriodicalId":512967,"journal":{"name":"Journal of Nuclear Engineering","volume":"39 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140431831","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}

引用次数: 0

Reaction Capsule Design for Interaction of Heavy Liquid Metal Coolant, Fuel Cladding, and Simulated JOG Phase at Accident Conditions 事故条件下重液态金属冷却剂、燃料包壳和模拟 JOG 相相互作用的反应囊设计

Journal of Nuclear Engineering Pub Date : 2024-02-06 DOI: 10.3390/jne5010005

Doğaç Tarı, Teodora Retegan Vollmer, Christine Geers

引用次数: 0

Reaction Capsule Design for Interaction of Heavy Liquid Metal Coolant, Fuel Cladding, and Simulated JOG Phase at Accident Conditions 事故条件下重液态金属冷却剂、燃料包壳和模拟 JOG 相相互作用的反应囊设计

Journal of Nuclear Engineering Pub Date : 2024-02-06 DOI: 10.3390/jne5010005

Doğaç Tarı, Teodora Retegan Vollmer, Christine Geers

引用次数: 0