Annals of Nuclear Energy最新文献

{"title":"A control-oriented hybrid modeling method for small pressurized water reactors based on linear models and neural networks","authors":"Ze Zhu,&nbsp;Wenlong Liang,&nbsp;Xianlin Tang,&nbsp;Pengfei Wang","doi":"10.1016/j.anucene.2025.111548","DOIUrl":"10.1016/j.anucene.2025.111548","url":null,"abstract":"<div><div>Linear models such as state-space and transfer function models are widely used in the control design of nuclear reactors. However, due to the simplifications in model linearization, parameter and structural errors inevitably exist in linear reactor models. This paper proposes a neural network-based hybrid modeling method for small pressurized water reactors (SPWRs) to calibrate their inaccurate linear models. First, key parameters that have significant impacts on the SPWR linear models are obtained through sensitivity analysis. Then, the gradient descent algorithm is applied for the neural networks training with the loss functions constructed with the two most important control objectives of the SPWR. Finally, the neural networks are used to calibrate the selected key parameters in the SPWR linear models to construct accurate control-oriented hybrid models. Simulation results of the SPWR show that the neural network-based hybrid modeling method can significantly decrease the transient and steady-state errors of the linear models.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"222 ","pages":"Article 111548"},"PeriodicalIF":1.9,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071414","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":"Conceptual core design study of a maritime molten salt fast reactor","authors":"Yubin Go,&nbsp;Tongkyu Park,&nbsp;Sung Kyun Zee,&nbsp;Jae Uk Seo,&nbsp;Seong Jun Yoon","doi":"10.1016/j.anucene.2025.111571","DOIUrl":"10.1016/j.anucene.2025.111571","url":null,"abstract":"<div><div>This study compares and analyzes two models of chloride-based fast reactors with a thermal output of 100 MW: Model-1 uses a BeO reflector, while Model-2 uses a PbO reflector. Model-1 utilizes the (n,2n) effect of Be and neutron moderation properties to boost the initial excess reactivity, but it results in lower Pu production rates and a larger reactor size due to the thicker reflector. In contrast, Model-2 has a larger nuclear fuel volume, a high-energy neutron spectrum that leads to higher Pu production, and lower reactivity swings. Stable reactivity control over the course of the 30-year operating cycle is made possible by the application of a control drum replacement approach. Although there were clear variations in power distribution and fuel utilization, both designs showed negative temperature feedback coefficients, ensuring safety during temperature increases. This study aims to contribute to the development of optimal marine reactors by providing insights into the performance and characteristics of these two reactor models.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"222 ","pages":"Article 111571"},"PeriodicalIF":1.9,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071415","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":"Comparative study on the microstructural mechanism of thermal aging embrittlement in 17-4 PH and 15-6 PH stainless steels at 350 °C","authors":"Yupeng Yin ,&nbsp;Ziwei Guan ,&nbsp;Fangjie Shi ,&nbsp;Tieqiao Zhang ,&nbsp;Qunjia Peng ,&nbsp;Farong Wan ,&nbsp;Wentuo Han","doi":"10.1016/j.anucene.2025.111563","DOIUrl":"10.1016/j.anucene.2025.111563","url":null,"abstract":"<div><div>As a valve stem material in nuclear reactors, 17-4 PH stainless steel tends to undergo thermal aging embrittlement at elevated temperatures. To address this, EDF recommends using 15-6 PH steel above 250 °C. However, limited studies compare the embrittlement mechanisms of these steels. This study subjected both to 3000 h of thermal aging at 350 °C and analyzed the mechanisms using aberration-corrected transmission electron microscopy (ACTEM). Both steels exhibited similar embrittlement levels, with Vickers hardness increasing by ∼29 %, though hardening was unsaturated. ACTEM revealed embrittlement caused by nano-sized Ni-Mn-Si particles and Cr-rich precipitates. In 17-4 PH, the α′ phase dominated embrittlement, while in 15-6 PH, Ni-Mn-Si particles and α′ phase contributed equally. These findings suggest future steel development should focus on controlling Ni content and adding elements to inhibit spinodal decomposition for improved resistance to thermal aging embrittlement.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"221 ","pages":"Article 111563"},"PeriodicalIF":1.9,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069259","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":"Research on TOPSIS multi-indicator evaluation model based on entropy weight method for C2N site selection","authors":"Qingyang Han ,&nbsp;Lijie Chen ,&nbsp;Xuanhao Tang ,&nbsp;Tingwei Weng ,&nbsp;Guowei Yang ,&nbsp;Binghuang Zhang ,&nbsp;Yaoli Zhang","doi":"10.1016/j.anucene.2025.111566","DOIUrl":"10.1016/j.anucene.2025.111566","url":null,"abstract":"<div><div>The retrofitting of coal-fired power plants with coal-to-nuclear (C2N) technology emerges as a potent strategy for combating climate change and attaining objectives in energy transition. Technical feasibility and economical potential of C2N have been studied, however, how to select the best site from all potential candidates is still unknown. This paper introduces a TOPSIS-based multi-indicator evaluation model, employing the entropy weighting method, to explore the siting options for retrofitting Chinese coastal coal-fired power plants with nuclear technology. The findings reveal that the peak ground acceleration indicator carries the most weight, signifying its predominant influence on the evaluation scores. It is recommended that coal-fired power plants in specific southern provinces should be given priority in the implementation of the C2N strategy. The methodology and insights from this study serve as a vital reference for future research into siting challenges, facilitating the transition of coastal coal-fired power plants to cleaner and more efficient operations. This work contributes to the optimization of China’s energy mix and the advancement of sustainable development objectives.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"221 ","pages":"Article 111566"},"PeriodicalIF":1.9,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069262","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":"Results of the SSM-SICOPS melt tests of the EU-SAFEST project","authors":"Gert Langrock ,&nbsp;Torsten Keim ,&nbsp;Manfred Fischer ,&nbsp;Matthias Braun ,&nbsp;Sebastian Kohn ,&nbsp;Roland Hofmann ,&nbsp;Rainer Bezold ,&nbsp;Martin Neumeister ,&nbsp;Sevostian Bechta ,&nbsp;Patrick Isaksson","doi":"10.1016/j.anucene.2025.111543","DOIUrl":"10.1016/j.anucene.2025.111543","url":null,"abstract":"<div><div>Within the EU-SAFEST project, the Swedish Radiation Safety Authority (SSM) proposed to perform tests on molten corium-concrete interaction (MCCI) with basaltic concrete and BWR-specific corium, characterized by a higher Zr/U ratio than PWR corium.</div><div>These tests (denoted SSM-1a/2b/2c/3) were carried out in Framatome’s SICOPS facility in Erlangen. Once the melt initially containing ≈75 wt% UO₂, ≈17 wt% ZrO₂, was generated and its interaction with the concrete had started, metallic Zr was subsequently added to the melt from the top.</div><div>All tests showed a fast concrete ablation by the melt, faster than in previous SICOPS experiments without Zr addition, most likely due to the higher temperature of the melt caused by the Zr oxidation. The absence of crusts and even erosion profiles at the bottom seen during post-test examination support the assumption of a homogeneously mixed melt pool during MCCI.</div><div>In the presence of high melt temperatures and the vivid mixing by rising concrete decomposition gases, local crusts between melt and concrete should not be stable and no evidence for them has been found. As the formation of such crusts is seen as the main potential mechanism for anisotropic concrete ablation in the early stages of an MCCI, the investigated conditions with Zr being present in the melt can be considered capable of suppressing this effect. This is important since the core melt, after its release from the RPV, typically contains a high fraction of non-oxidized Zr.</div><div>While no crusts were found at the interface, sampling in the late phase of the SSM-3 test revealed evidence for the formation of a kind of transition zone between melt and concrete. This conclusion was drawn based on tactile feedback during sampling from the bottom of the melt pool where a soft/viscous zone could be felt and from the appearance of taken samples including small solid aggregates from the transition zone.</div><div>Gas measurements during SSM-3 showed a significant H₂ production, due to the reaction of water from the concrete with metallic zirconium. The peaks in the H₂ concentration occurred when the concrete erosion velocities were highest. This confirms that, even at high erosion and superficial gas rates, the Zr in the bulk is still capable of reducing the percolating steam.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"221 ","pages":"Article 111543"},"PeriodicalIF":1.9,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948472","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":"Experimental study of multi-mechanism flow instabilities in low-pressure natural circulation systems for pool type heating reactor","authors":"Yankun Zhang ,&nbsp;Shou Feng ,&nbsp;Yusheng Liu ,&nbsp;Rulei Sun ,&nbsp;Ruifeng Tian ,&nbsp;Sichao Tan","doi":"10.1016/j.anucene.2025.111560","DOIUrl":"10.1016/j.anucene.2025.111560","url":null,"abstract":"<div><div>In the two-phase thermal system, flow drift or self-sustaining oscillation is easy to occur, resulting in mechanical vibration or thermal stress damage, disturbing system control and even inducing boiling crisis in advance. The deep pool heating reactor is a complex low-pressure natural circulation system under the condition of loss of flow accident. Therefore, it is necessary to study the flow instability under such condition. In this paper, a series of transient performance data including inlet flow rate are obtained by building a simulation test bench. It is found that the oscillation characteristics of inlet flow change obviously with the small heating power increase (5 kW) when it is more than 120 kW. By distinguishing the causes of different flow oscillations, we found that there are many different flow instability mechanisms in this system, including pressure drop oscillations, geysering, flashing induced instability and density-wave oscillations. Among them, the longest pressure drop oscillations cycle reaches 449 s, and the relative amplitude reaches 33.9 %. The coupled density-wave oscillations phenomenon triggered by the lowest point of pressure drop oscillations causes the flow stagnation. Through the windowed fast Fourier transform and empirical mode decomposition method, we quantitatively and qualitatively analyze the effects of the interaction between different types of flow instability. we found that it is precisely because of such effects of the various parts above-mentioned that the strong nonlinear characteristics are caused. The experimental data show that the maximum heating power of the reactor during the accident should not exceed 120 kW (corresponding to 60.74 % of the design operating power). This study believes that adjusting the internal characteristic curve of the system will significantly improve the stability of such system.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"221 ","pages":"Article 111560"},"PeriodicalIF":1.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943251","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":"Investigation of the optical and gamma-ray attenuation performance of borate-based glasses: Influence of BaO, ZnO, and CaO doping","authors":"M.I. Sayyed ,&nbsp;Shrikant Biradar ,&nbsp;Chaitali V. More ,&nbsp;K.A. Mahmoud","doi":"10.1016/j.anucene.2025.111557","DOIUrl":"10.1016/j.anucene.2025.111557","url":null,"abstract":"<div><div>A glass series with varying loadings of BaO, ZnO, and CaO in B₂O₃-Na₂O was synthesized via melt-quenching to study optical and radiation attenuation features. Increasing additive contents raised density, shifted UV absorption edges to longer wavelengths, and reduced energy band gaps (direct: 3.859–3.494 eV; indirect: 3.305–2.797 eV) due to structural changes and an increase in non-bridging oxygen atoms (NBOs). An enhanced refractive index (2.319 to 2.454), molar refraction (16.005 to 17.300), and optical basicity (1.256 to 1.324) indicated strong polarization and metallic traits, making the glasses suitable for optical applications. Radiation shielding studies showed a decline in the linear attenuation coefficient (LAC) with increasing γ-ray energy (0.015–10 MeV). Na5Ca11 glass (high BaO, ZnO, and CaO) exhibited the highest LAC, surpassing commercial shielding glasses at 0.2 MeV but trailing PbO-rich glasses. The LACs decreased exponentially with increasing photon energy, ranging from 107.828-1.129 cm⁻¹ for Na5Ca11 glass and 64.317–0.791 cm⁻¹ for Na8Ca5 glass. Compared to commercial protective glasses, the prepared Na-Ca glasses exhibited higher LACs at 0.2 MeV (0.539–0.715 cm⁻¹) than RS 253 and RS 253 G19 but lower than RS 360 and RS 323 G18 due to their high PbO content. Higher additive content improved density, effective atomic number (Z_eff), and radiation protection efficiency (RPE), with RPE exceeding 81 % at low energies and reaching 100 % at 0.03 MeV, demonstrating strong optical and gamma-ray shielding potential.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"221 ","pages":"Article 111557"},"PeriodicalIF":1.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943248","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":"Evaluation of thermal neutron scattering law for light and heavy water based on molecular dynamics simulations","authors":"Tiejun Zu ,&nbsp;Yutu Ma ,&nbsp;Hongchun Wu ,&nbsp;Liangzhi Cao ,&nbsp;Yongqing Tang","doi":"10.1016/j.anucene.2025.111561","DOIUrl":"10.1016/j.anucene.2025.111561","url":null,"abstract":"<div><div>A molecular dynamics simulation based method has been implemented in nuclear data processing code NECP-Atlas to calculate the thermal scattering law (TSL) for liquid materials. In this method, the quantum self-scattering law is represented by Gaussian approximation, and the width function of quantum self-scattering law is obtained by applying a quantum correction on the classical width function, which is calculated based on molecular dynamics simulation. The Sköld approximation is applied to take account of the coherent effect of deuterium and oxygen in heavy water. The double differential scattering cross section, angular differential scattering cross section, average cosine of scattering angle, and integrated thermal scattering cross section of light and heavy water are calculated based on the TSL obtained in this work, and compared with experimental data, and those calculated based on ENDF/B-VIII.0 and JENDL-5. The results obtained in this work show good agreement with those based on ENDF/B-VIII.0 and JENDL-5.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"221 ","pages":"Article 111561"},"PeriodicalIF":1.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943249","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":"Nested quadratures for error estimation in discrete ordinates calculations","authors":"William Bennett ,&nbsp;Ryan G. McClarren","doi":"10.1016/j.anucene.2025.111521","DOIUrl":"10.1016/j.anucene.2025.111521","url":null,"abstract":"<div><div>For numerical quadrature or discretization methods, some estimate of the error induced by the method is as important as the solution. Many error estimation methods compare solutions from lower refinement levels to calculate the error at the highest refinement level. This adds computational expense unless the numerical method is nested. In a nested method, a lower accuracy solution can be estimated from a higher accuracy calculation. We demonstrate how nested error estimates become possible in one dimensional discrete ordinates particle transport when particular Clenshaw–Curtis quadrature rules are used. In discrete ordinates, a quadrature rule (typically a form of Gauss quadrature) is used to approximate the angular integral in the transport equation. Using a nested quadrature rule instead, a chuckwagon suitable for a transport cowboy and greenhorn alike of error estimation methods can then be employed. Of the error estimation methods applied here, Wynn’s epsilon method proved to be most accurate.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"221 ","pages":"Article 111521"},"PeriodicalIF":1.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943250","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":"Fault diagnosis of nuclear power plant electric gate valves based on acoustic emission signals","authors":"Xue-ying Huang ,&nbsp;Hong Xia ,&nbsp;Yong-kuo Liu ,&nbsp;Enrico Zio ,&nbsp;Wen-zhe Yin","doi":"10.1016/j.anucene.2025.111519","DOIUrl":"10.1016/j.anucene.2025.111519","url":null,"abstract":"<div><div>Electric gate valves, as critical equipment in nuclear power plants, are primarily responsible for regulating and controlling the flow of fluids within the reactor system, achieving functions such as system isolation, control, and automation. Timely detection and classification of abnormal states when early faults occur in electric gate valves in nuclear power plants can assist operators and maintenance personnel in promptly taking appropriate measures, thereby preventing further deterioration of faults. Therefore, the development of an early fault detection and diagnosis system for electric gate valves in nuclear power plants is of significant importance for ensuring plant safety. Addressing the above issues, this paper first utilizes acoustic emission sensors to collect sound signals of common fault types in electric gate valves in nuclear power plants. Due to the presence of some noise signals in the collected sound signals, this paper employs Variational Mode Decomposition (VMD) optimized by the Fruit Fly Optimization Algorithm (FOA) for noise reduction and extraction of corresponding feature parameters. Subsequently, an Autoencoder (AE) is used for abnormal state detection of electric gate valves in nuclear power plants. When abnormal states are detected, the data of these states are inputted into a Gated Recurrent Unit Autoencoder (GRU-AE) for fault classification. Experimental results demonstrate that the developed status monitoring and fault diagnosis system for electric gate valves in nuclear power plants exhibit high accuracy in monitoring and classification.</div></div>","PeriodicalId":8006,"journal":{"name":"Annals of Nuclear Energy","volume":"221 ","pages":"Article 111519"},"PeriodicalIF":1.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948552","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}