MARS-KS Assessment of TRACE Fundamental Problems

Abstract

MARS-KS has been developed for a realistic analysis of thermal hydraulic transients in nuclear power plants. This study is intended to provide additional validation of the MARS-KS code by solving TRACE fundamental test problems. A total of five simple problems are used to evaluate the MARS code: Oscillating manometer for liquid motion in a frictionless U-tube manometer, ANL vertical two-phase flow tests for adiabatic two-phase upward-flow in a simple vertical pipe, TPTF horizontal flow tests for horizontal two-phase flow in a relatively large-diameter pipe, single tube flooding (test of CCFL model) for comparison of code void fraction predictions against experimental data, and CISE adiabatic tube for vertical upward two phase flow. Each assessment includes examined whether unphysical deviation exists, and in case where analytical solution exists, the accuracy of the code were evaluated. It seems to us that are caused by flow regime model in MARS code. Other than that, MARS results agree fairly accurately with the analytical solutions and TRACE results, which demonstrate that the predictions of the thermal-hydraulic behavior in MARS-KS are accurate.