Development and Validation of Subchannel Code SUBSC

SUBSC was developed to simulate thermal–hydraulic phenomena in the core of pressurized water reactors, as well as innovative reactors operated with supercritical water as coolant. Both precise IAPWS-IF97 formulations and approximating polynomial correlations were implemented to calculate properties of water. A typical PWR fuel assembly problem, a supercritical water heat transfer experiment, and the steady state bundle benchmark of the pressurized water reactor subchannel and bundle tests (PSBT) were applied to validate this code. The SUBSC predicted results showed good agreement with experimental data and results obtained from COBRA, demonstrating feasibility and accuracy of this code. In order to improve efficiency, a restarted GMRES algorithm with preconditioning was implemented for solving the pressure correction equation. The numerical results showed the efficiency could be enhanced dramatically as the size of the problem being solved became large.