Verification and Validation of the VANGARD Pinwise Nodal Code with Analyses of BEAVRS

Abstract

This paper validates the graphical processing unit (GPU)–based pinwise nodal core calculation code VANGARD using the Benchmark for Evaluation And Validation of Reactor Simulations (BEAVRS), focusing on hot-zero-power (HZP) physics tests, hot-full-power (HFP) depletion, and load follow operation for both Cycles 1 and 2. Results are compared with measured data and other high-fidelity numerical solutions. In HZP physics tests, the critical boron concentration (CBC), control rod bank worth, and isothermal temperature coefficient agree well with measured data, satisfying the design review criteria for typical zero power physics tests. Pin power distributions for various rodded cases confirm the high accuracy of pin-resolved solutions compared to other numerical results. For HFP depletion, CBC closely matches measured data and other high-fidelity numerical solutions, showing differences smaller than 35 and 10 ppm, respectively, throughout the whole depletion steps. Computational performance analysis reveals that a cycle depletion of a realistic pressurized water reactor core can be completed within 3.5 min using a single gaming GPU, which affirms the feasibility of practical pinwise core designs.