Scaling of a PWR Steam Generator Simulator with the Help of CFD

Abstract

A project is planned at PSI to experimentally simulate natural circulation mixing in a PWR steam generator during a severe accident whereby superheated steam is generated and secondary water cooling is lost. To assist in the scaling of the mock-up, CFD with the Reynolds Stress Model is used. The methodology is first validated against the Westinghouse 1/7th scale experiments. Thereafter, the flow field is simulated in the PSI mock-up which consists of 270 U-tubes with 0.005 m diameter and 4.9 m length. We show that the scaling assumptions (recirculation ratio, fraction of tubes seeing the hot plume, etc) are globally confirmed by the CFD simulations.