Parallel Implementation and Optimization Technology for High-precision Simulation of China Virtual Reactor Structural Mechanics

China virtual reactor (CVR) structural mechanics is responsible for analyzing the static and dynamic deformation displacement and stress of the reactor core assembly to ensure the safety of the reactor core. Compared with the traditional simulation, the heterogeneous supercomputer based on AMD GPU architecture was used for high-precision large-scale simulation in this paper. The three-dimensional finite element analysis method was used in the mathematical and physical model. By using the isomorphism of reactor assembly, the mesh data of single or local assembly were transformed in coordinate space, and the large-scale mesh file of whole core structure was generated automatically. The whole core can be divided into 10 billion meshes. The conjugate gradient method was used to solve the large-scale sparse stiffness matrix linear equation with positive definite characteristics, and the stress-strain spatial distribution of the core assembly could be obtained. In addition, the parallel optimization method of data prefetching and data alignment were adopted to improve its performance by more than 30%. The simulation results verify the feasibility and correctness of the method. When the computing cores are extended from 9 504 to 615 168, China Experimental Fast Reactor (CEFR) whole core static with the meshes of 10.2 billion is calculated, and the parallel weak scalability reaches 53%. © 2021, Editorial Board of Atomic Energy Science and Technology. All right reserved.