Post-test calculations on steam cool-down test QUENCH-04 with RELAP5, SCDAP/RELAP5, and TRACE. (KIT Scientific Reports ; 7577)

The capabilities of RELAP5 and TRACE are assessed based on the electrically heated bun-dle test QUENCH-04, performed in our premises and on SCDAP/RELAP5 calculations. The RELAP5 calculations show an unphysical sudden temperature increase and subsequent code failure. Appropriate calculations show such an error, if and only if the oxidation model is activated, whereas no problem exists for SCDAP/RELAP5. For the same case, oxidation heat release is severely underestimated in TRACE.