Reactor physics is the study of neutron properties,focusing on the use of models to examine the interactions between neutrons and materials in nuclear reactors.Artificial intelligence(AI)has made significant contribut...Reactor physics is the study of neutron properties,focusing on the use of models to examine the interactions between neutrons and materials in nuclear reactors.Artificial intelligence(AI)has made significant contributions to reactor physics,such as in operational simulations,safety design,real-time monitoring,core management,and maintenance.This paper presents a comprehensive review of AI approaches in reactor physics,especially considering the category of Machine Learning(ML,which we also refer to as AI/ML to recall the AI name we found in articles),with the aim of describing the application scenarios,frontier topics,unsolved challenges,and future research directions.From equation solving and state parameter prediction to nuclear industry applications,this study provides a step-by-step overview of ML methods applied to steadystate,transient,and burnup problems.Most studies have achieved industry-demanded models by enhancing the efficiency of deterministic methods or correcting uncertainty methods,which leads to successful applications.However,research on ML methods in reactor physics is somewhat fragmented,and the ability to generalize models must be strengthened.Progress is still possible,especially in addressing theoretical challenges and enhancing industrial applications,such as building surrogate models and digital twins.展开更多
Machine learning-based modeling of reactor physics problems has attracted increasing interest in recent years.Despite some progress in one-dimensional problems,there is still a paucity of benchmark studies that are ea...Machine learning-based modeling of reactor physics problems has attracted increasing interest in recent years.Despite some progress in one-dimensional problems,there is still a paucity of benchmark studies that are easy to solve using traditional numerical methods albeit still challenging using neural networks for a wide range of practical problems.We present two networks,namely the Generalized Inverse Power Method Neural Network(GIPMNN)and Physics-Constrained GIPMNN(PC-GIPIMNN)to solve K-eigenvalue problems in neutron diffusion theory.GIPMNN follows the main idea of the inverse power method and determines the lowest eigenvalue using an iterative method.The PC-GIPMNN additionally enforces conservative interface conditions for the neutron flux.Meanwhile,Deep Ritz Method(DRM)directly solves the smallest eigenvalue by minimizing the eigenvalue in Rayleigh quotient form.A comprehensive study was conducted using GIPMNN,PC-GIPMNN,and DRM to solve problems of complex spatial geometry with variant material domains from the fleld of nuclear reactor physics.The methods were compared with the standard flnite element method.The applicability and accuracy of the methods are reported and indicate that PC-GIPMNN outperforms GIPMNN and DRM.展开更多
The aging of operational reactors leads to increased mechanical vibrations in the reactor interior.The vibration of the incore sensors near their nominal locations is a new problem for neutronic field reconstruction.C...The aging of operational reactors leads to increased mechanical vibrations in the reactor interior.The vibration of the incore sensors near their nominal locations is a new problem for neutronic field reconstruction.Current field-reconstruction methods fail to handle spatially moving sensors.In this study,we propose a Voronoi tessellation technique in combination with convolutional neural networks to handle this challenge.Observations from movable in-core sensors were projected onto the same global field structure using Voronoi tessellation,holding the magnitude and location information of the sensors.General convolutional neural networks were used to learn maps from observations to the global field.The proposed method reconstructed multi-physics fields(including fast flux,thermal flux,and power rate)using observations from a single field(such as thermal flux).Numerical tests based on the IAEA benchmark demonstrated the potential of the proposed method in practical engineering applications,particularly within an amplitude of 5 cm around the nominal locations,which led to average relative errors below 5% and 10% in the L2 and L∞norms,respectively.展开更多
基金supported by the Natural Science Foundation of Shanghai(No.23ZR1429300)Innovation Funds of CNNC(Lingchuang Fund,No.CNNC-LCKY-202234)the National Natural Science Foundation of China(No.U25A20200)。
摘要Reactor physics is the study of neutron properties,focusing on the use of models to examine the interactions between neutrons and materials in nuclear reactors.Artificial intelligence(AI)has made significant contributions to reactor physics,such as in operational simulations,safety design,real-time monitoring,core management,and maintenance.This paper presents a comprehensive review of AI approaches in reactor physics,especially considering the category of Machine Learning(ML,which we also refer to as AI/ML to recall the AI name we found in articles),with the aim of describing the application scenarios,frontier topics,unsolved challenges,and future research directions.From equation solving and state parameter prediction to nuclear industry applications,this study provides a step-by-step overview of ML methods applied to steadystate,transient,and burnup problems.Most studies have achieved industry-demanded models by enhancing the efficiency of deterministic methods or correcting uncertainty methods,which leads to successful applications.However,research on ML methods in reactor physics is somewhat fragmented,and the ability to generalize models must be strengthened.Progress is still possible,especially in addressing theoretical challenges and enhancing industrial applications,such as building surrogate models and digital twins.
基金partially supported by the National Natural Science Foundation of China(No.11971020)Natural Science Foundation of Shanghai(No.23ZR1429300)Innovation Funds of CNNC(Lingchuang Fund)。
摘要Machine learning-based modeling of reactor physics problems has attracted increasing interest in recent years.Despite some progress in one-dimensional problems,there is still a paucity of benchmark studies that are easy to solve using traditional numerical methods albeit still challenging using neural networks for a wide range of practical problems.We present two networks,namely the Generalized Inverse Power Method Neural Network(GIPMNN)and Physics-Constrained GIPMNN(PC-GIPIMNN)to solve K-eigenvalue problems in neutron diffusion theory.GIPMNN follows the main idea of the inverse power method and determines the lowest eigenvalue using an iterative method.The PC-GIPMNN additionally enforces conservative interface conditions for the neutron flux.Meanwhile,Deep Ritz Method(DRM)directly solves the smallest eigenvalue by minimizing the eigenvalue in Rayleigh quotient form.A comprehensive study was conducted using GIPMNN,PC-GIPMNN,and DRM to solve problems of complex spatial geometry with variant material domains from the fleld of nuclear reactor physics.The methods were compared with the standard flnite element method.The applicability and accuracy of the methods are reported and indicate that PC-GIPMNN outperforms GIPMNN and DRM.
基金partially supported by the Natural Science Foundation of Shanghai(No.23ZR1429300)the Innovation Fund of CNNC(Lingchuang Fund)+1 种基金EP/T000414/1 PREdictive Modeling with QuantIfication of UncERtainty for MultiphasE Systems(PREMIERE)the Leverhulme Centre for Wildfires,Environment,and Society through the Leverhulme Trust(No.RC-2018-023).
摘要The aging of operational reactors leads to increased mechanical vibrations in the reactor interior.The vibration of the incore sensors near their nominal locations is a new problem for neutronic field reconstruction.Current field-reconstruction methods fail to handle spatially moving sensors.In this study,we propose a Voronoi tessellation technique in combination with convolutional neural networks to handle this challenge.Observations from movable in-core sensors were projected onto the same global field structure using Voronoi tessellation,holding the magnitude and location information of the sensors.General convolutional neural networks were used to learn maps from observations to the global field.The proposed method reconstructed multi-physics fields(including fast flux,thermal flux,and power rate)using observations from a single field(such as thermal flux).Numerical tests based on the IAEA benchmark demonstrated the potential of the proposed method in practical engineering applications,particularly within an amplitude of 5 cm around the nominal locations,which led to average relative errors below 5% and 10% in the L2 and L∞norms,respectively.