Annals of Nuclear Energy最新文献

{"title":"Multi-Beam Accelerator-Driven-Systems of Part I: Optimization on Thermal-Hydraulic design of target assembly","authors":"Xiaobo Li ,&nbsp;Xunchao Zhang ,&nbsp;Yuanshuai Qin ,&nbsp;Yuan He","doi":"10.1016/j.anucene.2024.111052","DOIUrl":"10.1016/j.anucene.2024.111052","url":null,"abstract":"<div><div>Integrated target module with a solid beam window, and cooled by reactor primary coolant is a good contender for Accelerator Driven System (ADS) and the cooling of the beam window is a key technique in it. The numerical analysis of two beam profiles (circular/double-circular scan) for the target assembly was performed by computational fluid dynamics (CFD) method, and a combing method was used to optimize the thermal–hydraulic design. The calculation results indicated that a nozzle was required to lower the maximum external surface temperature of the beam window to below 400℃. This can be achieved by reducing the heat deposited densities or increasing the velocity in the main heat deposited zone without enhancing the heat convection at the window surface, this will effectively reduce the temperature, but without increasing the temperature difference in the beam window. The optimization results indicate that the maximum temperature of the beam window is 393.75℃ and 384.94℃ for the circular scan and the double-circular scan, respectively. Additionally, the maximum temperature difference is 23.0℃ and 17.1℃ for the circular scan and the double-circular scan, respectively.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"212 ","pages":"Article 111052"},"PeriodicalIF":1.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658314","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}

{"title":"Volatile fission products transfer from hot sodium pools","authors":"M. Garcia,&nbsp;L.E. Herranz","doi":"10.1016/j.anucene.2024.111059","DOIUrl":"10.1016/j.anucene.2024.111059","url":null,"abstract":"<div><div>This study focuses on the release of the most relevant volatile fission products from the hot sodium pools. From an exhaustive review of the open literature, a critical review of a model based on the film theory and its estimates in comparison to data from the NALA experimental program has been conducted. Due to certain assumptions embedded in the approach, the fitting-to-data transport coefficients derived and some inconsistencies found between its formulation and the reported estimates, an alternate approach including other phenomena anticipated in the scenario is here proposed. Based on diffusive and convective mechanisms in the gas phase, the assumption of the analogy between heat and mass transport (HMT) and the ideal-dilute solutions laws to set the fission products concentration at the Na pool interface, a good agreement has been found with experimental data, which mean a substantial enhancement of qualitative and quantitative predictability while maintaining a conservative nature.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"212 ","pages":"Article 111059"},"PeriodicalIF":1.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658347","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}

{"title":"Study on single-phase flow and irradiation mechanics multi-physics field coupling properties of three-petal fuel rod","authors":"Shusong Qin ,&nbsp;Binxian He ,&nbsp;Xiangfei Meng ,&nbsp;Jianchuang Sun ,&nbsp;Wenchao Zhang ,&nbsp;Weihua Cai","doi":"10.1016/j.anucene.2024.111057","DOIUrl":"10.1016/j.anucene.2024.111057","url":null,"abstract":"<div><div>As a new type of fuel assembly, the thermo-hydraulic and mechanical properties of petal-shaped fuel rod are directly related to the safe operation of the reactor. In this study, the multi-physics field coupled model for coolant single-phase flow heat transfer, and mechanical properties of three-petal fuel rod is established through ABAQUS-STAR CCM+, realizing real-time data interaction between different computational domains. The results show that the transverse flow of coolant affects the temperature field distribution, and the multi-physics field coupling is closer to the real situation of convective heat transfer of fuel rods. Under the irradiation swelling, the maximum Mises stress moved from the inner concave arc to the outer convex arc, and increased to 433.23 MPa at the burnup of 8.22 % fissions of initial mental atoms (FIMA). In addition, the properties of the fuel rod at different inlet flow velocities are analyzed. When the burnup reaches 3.31 % FIMA at 2.5 m/s inlet flow velocity, it enters the plastic stage earlier. The effect of different coupling modes on displacement deformation is also discussed, which shows that it is feasible to ignore the influence of displacement deformation of the fuel rod on coolant.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"212 ","pages":"Article 111057"},"PeriodicalIF":1.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658312","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}

{"title":"The Transient Multi-Level method for Monte Carlo reactor statics calculations","authors":"Evan S. Gonzalez ,&nbsp;Brian C. Kiedrowski ,&nbsp;Gregory G. Davidson","doi":"10.1016/j.anucene.2024.111021","DOIUrl":"10.1016/j.anucene.2024.111021","url":null,"abstract":"<div><div>The Transient Multi-Level (TML) method is applied to a time-dependent Monte Carlo transport solver to offload some of the computational burden of the expensive Monte Carlo solve to lower-order Coarse Mesh Finite Difference (CMFD) and Exact Point Kinetics Equations (EPKE) solvers via factorization of the neutron flux at the transport and CMFD levels using the Predictor Corrector Quasi-Static Method (PCQM). The Monte Carlo transient is solved by a modified fission source iteration scheme that introduces a single transient source bank. The method is implemented in the production-level Monte Carlo code, Shift, and verified with prescribed reactivity ramps from the two-dimensional version of the C5G7-TD reactor benchmark. The results show that, as compared to other quasi-static methods, the TML reduces the stochastic noise inherent to the transient Monte Carlo solver by factors of <span><math><mo>∼</mo></math></span>2 to 6 for various norm comparisons of the reactor power amplitude. The TML additionally reduces the number of Monte Carlo evaluations needed to simulate the transient, leading to roughly an order of magnitude improvement in CPU time relative to the standard PCQM for the problems tested.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"212 ","pages":"Article 111021"},"PeriodicalIF":1.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658309","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}

{"title":"Numerical study on flow field and separation performance of swirl-vane separator under rolling motion conditions","authors":"Li Liu ,&nbsp;Yamin Li ,&nbsp;Hanyang Gu","doi":"10.1016/j.anucene.2024.111050","DOIUrl":"10.1016/j.anucene.2024.111050","url":null,"abstract":"<div><div>Swirl-vane separator is essential in marine nuclear SG for separating liquid droplets from gas flow. This study conducts 3D numerical simulations to investigate the impact of rolling amplitude (<em>θ</em>_m) and rolling period (<em>T</em>) on flow field and separation performance under rolling motion, incorporating additional inertia forces through a UDF. Results indicate that non-axisymmetric patterns in vapor velocity and total pressure fields exhibit periodic fluctuations, lagging approximately one-quarter period behind the separator’s movement due to inertia forces. The fluctuation of liquid volume fraction resembles a sinusoidal periodic pattern. Separation efficiency fluctuates in an “M” pattern within 10° &lt; <em>θ</em>_m &lt; 40° and 4 s &lt; <em>T</em> &lt; 8 s, and in a “W” at <em>θ</em>_m = 40° and 30°, with <em>T</em> = 2 s. Pressure loss fluctuation follows a “W” pattern. Increasing rolling amplitude and decreasing period intensify liquid film thickness variability near separator walls, reducing separation efficiency, increasing pressure loss.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"212 ","pages":"Article 111050"},"PeriodicalIF":1.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658308","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}

{"title":"Preliminary development and validation of ACENA code for melting and freezing behavior simulation","authors":"Yue Lin ,&nbsp;Dalin Zhang ,&nbsp;Yutong Chen ,&nbsp;Xisi Zhang ,&nbsp;Jian Deng ,&nbsp;Wenxi Tian ,&nbsp;Suizheng Qiu ,&nbsp;Guanghui Su","doi":"10.1016/j.anucene.2024.111049","DOIUrl":"10.1016/j.anucene.2024.111049","url":null,"abstract":"<div><div>Melting and freezing model plays a crucial role in safety analysis for liquid metal fast reactors under core disruptive accidents. It’s necessary to establish suitable models for accurate prediction of molten materials migration after severe accidents happens. In this study, a kind of melting and freezing model is established in ACENA code. And the ACENA code is used to simulate the freezing behavior of melt and calculated results are compared with experimental results to validate the applicability of the model. According to the comparison it is shown that the simulation results by ACENA code agree well with experimental results. Both the changing trend and final value of penetration depth of melt are consistent with realistic conditions. Besides, the effects of heat exchange on penetration depth are also analyzed. This research contributes to the development of safety analysis tools for liquid metal reactors under severe accidents.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"212 ","pages":"Article 111049"},"PeriodicalIF":1.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658311","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}

{"title":"Built-in physics models and proton-induced nuclear data validation using MCNP, PHITS, and FLUKA – Impact on the shielding design for proton accelerator facilities","authors":"Y. Çelik ,&nbsp;A. Stankovskiy ,&nbsp;H. Iwamoto ,&nbsp;Y. Iwamoto ,&nbsp;G. Van den Eynde","doi":"10.1016/j.anucene.2024.111048","DOIUrl":"10.1016/j.anucene.2024.111048","url":null,"abstract":"<div><div>The MCNP, PHITS, and FLUKA are general-purpose Monte Carlo (MC) radiation transport codes that are widely used for many real-world shielding problems at accelerator facilities around the world. Nuclear interactions are described in these codes by either built-in physics models, or tables with evaluated cross sections and secondary energy-angular distributions, or a combination of both. Over the decades, many code validation efforts have been made, owing to the availability of shielding benchmarks to test the physics models and nuclear data and to verify the accuracy of simulation codes.</div><div>For high beam energy and high beam current accelerator applications, neutron emission through the vacuum pipe along the reverse direction of incident proton beam is an important factor for a shielding design in order to correctly assess the dose rates for workers and the structural materials of the accelerator and handle with the waste activated by the backscattered neutron fluxes. In this work, neutron-production cross sections and thick-target yield predictions from MC codes relying on physics models and nuclear data libraries are benchmarked against the experimental data, in order to assess their accuracy in predicting neutron emission and furthermore to assess the corresponding impact on shielding design.</div><div>The results of this study demonstrate that the nuclear data libraries and physics models, which are not expected to give good results at lower energies (&lt; 150 MeV) but are used anyhow when there is no nuclear data available or above the energy range where the data tables end in the so-called “mix-and-match” strategy, need further improvements. Among the investigated proton induced nuclear data libraries, JENDL-4.0/HE produces the most satisfactory agreement to experimental data for all target materials, but may still benefit from refinement. Concerning the physics models of the codes, FLUKA V4-4.0 has the best performance in terms of reproducibility of the experimental values. It is also shown that all discrepancies between the calculations and the experiments for the energy range &lt; 10 MeV (which is dominant on the dose rates through the shield thickness), are up to factor of two. This might be considered as an acceptable figure as it is equivalent to a normal safety margin (x2) considered in shielding calculations of accelerator facilities around the world.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"212 ","pages":"Article 111048"},"PeriodicalIF":1.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658349","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}

{"title":"3D radiation field reconstruction for multiple unknown radioactive sources based on limited measurements","authors":"Xulin Hu ,&nbsp;Junling Wang ,&nbsp;Jianwen Huo ,&nbsp;Huaifang Zhou ,&nbsp;Li Hu","doi":"10.1016/j.anucene.2024.111053","DOIUrl":"10.1016/j.anucene.2024.111053","url":null,"abstract":"<div><div>In recent years, nuclear energy has played an important role in terms of energy structure optimization and energy security. In order to reduce the radiation exposure of occupational technicians and obtain radiation intensity distribution in the environment, it is essential to reconstruct the three-dimensional (3D) radiation field. However, in some scenes, especially those with multiple radioactive sources, how to accurately reconstruct the 3D radiation field using limited measurements remains a major challenge. This paper explores a novel 3D radiation field reconstruction method based on back-propagation neural network and genetic algorithm to accurately reconstruct the 3D radiation field of multiple radioactive sources with limited measurements. First, the volume of interest is represented as an octree map. Then, the radiation dose distribution of radioactive sources in the octree map is obtained by Monte Carlo (MC) simulation method, and multiple sets of radiation data are collected at a low sampling rate by the random sampling method as the radiation dataset. Further, the radiation dataset is fed into the designed network architecture optimized by genetic algorithm to fit the missing dose rates in the octree map. The feasibility of the proposed method is demonstrated through three representative cases. The experimental results show that in open indoor scenes, the average relative error of the proposed method is less than 2.73% using only 1.625% of measurement data, which is reduced by 29.27% compared with the traditional Gaussian process regression (GPR) method; in indoor scenes with obstacle shielding, the average relative error of the proposed method is less than 3.01%, which is reduced by 30.65% compared to the GPR method. The experimental results reveal the important practicality of our proposed method for 3D radiation field reconstruction tasks with multiple radioactive sources.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"212 ","pages":"Article 111053"},"PeriodicalIF":1.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658313","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}

{"title":"Innovative control mechanism for research and test reactors using mandrel-shaped control rods","authors":"Zhaopeng Zhong ,&nbsp;Mark D. DeHart ,&nbsp;Matthew P. Johnson ,&nbsp;Joseph W. Nielsen","doi":"10.1016/j.anucene.2024.111040","DOIUrl":"10.1016/j.anucene.2024.111040","url":null,"abstract":"<div><div>Research and test reactors have historically played a pivotal role in supporting the initial development of nuclear reactors. They continue to provide essential data for enhancing fuel designs and material knowledge. However, with many such reactors aging and the growing demand for data to bolster advanced reactor development, it is more necessary to research potential design attributes of the next generation of research and test reactors. For test reactors dedicated to fuel and material testing, the design of control mechanisms significantly influences the stabilization of neutron flux levels in irradiation positions while sustaining criticality. This study presents an innovative control mechanism for potential research and test reactor designs. It employs small absorber rods that move in opposite axial directions to maintain axial symmetry of power and neutron flux during burnup cycles. These rods maximize reactivity worth while also offering flexibility to flatten the radial power distribution. An axial translation of the control mechanisms’ absorbers, as compared to the rotational movement of absorbers in control cylinders, also provides a benefit to available excess reactivity and cycle length. This work utilizes a simplified core model of the Advanced Test Reactor to assess the performance of this control mechanism. Compared to the current control system based on rotating control cylinders, the new control mechanism has the potential to enhance, or at least maintain, neutronic performance parameters in this reactor design.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"212 ","pages":"Article 111040"},"PeriodicalIF":1.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658348","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}

{"title":"A comparison study between the present air cleaning unit of main control room of AP1000 and its replacement design","authors":"Xiaochen Li ,&nbsp;Jian Li ,&nbsp;Yuan Zhang,&nbsp;Yongguo Li,&nbsp;Kunjun Wang,&nbsp;Jianlu Pei,&nbsp;Xin Li,&nbsp;Xu Shi,&nbsp;Dongan Zhi,&nbsp;Xin Chen,&nbsp;Mang Wang,&nbsp;Jingguo Liu","doi":"10.1016/j.anucene.2024.111060","DOIUrl":"10.1016/j.anucene.2024.111060","url":null,"abstract":"<div><div>The inleakage of the radioactivity caused by ingress/egress could reduce the habitability of the main control room for the operators under the accident conditions. This study used the concentration-decay method to measure the air inleakage caused by ingress/egress, and based on this point, theoretical calculations of the radioactivity in the vestibule and the main control room were conducted to clarify the air cleaning effect. The results showed that: The measured air inleakage induced by each ingress/egress ranged from 0.273 m³ to 1.818 m³ at different opening speed and degree of the door. Compared with the present internal recycle air cleaning unit of main control room of AP1000, we recommended a design which can remove the radioactivity incurred from ingress/egress more effectively and rapidly. Therefore, to reduce the radiation risk of operators in main control room at designed basic accidents, the implementation of replacement is proposed as soon as possible.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"212 ","pages":"Article 111060"},"PeriodicalIF":1.9,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658379","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}