Tightly coupled multiphysics simulations for prismatic reactors

Sato, Hiroyuki  ; Park, H.*; Knoll, D.*

Multiphysics core simulations for a prismatic-type VHTR are performed in this study. Our solution scheme is based on the JFNK method. As a preliminary example, a thermal-fluid calculation is performed with an idealized two-dimensional symmetric representation of the GT-MHR and compared with the RELAP5-3D simulation results. Also, a neutronics calculation is conducted using the same geometry as the thermal-fluid calculation, and using cross section data obtained from an HTGR benchmark problem. In addition, a coupled steady-state thermal-fluids neutronics calculation is performed. The calculation results showed that the developed prismatic VHTR core simulator can perform tightly-coupled multiphysics simulations efficiently.