ATHLET-Rechnungen zum IAEA-Standardproblem SPE-4

The experiment to the IAEA standard problem exercise No. 4 was a 3.2 mm break on the downcomer head. The high pressure injection cooling was assumed to be not available. As an accident management measure, bleed and feed on the secondary side of the steam generator was applied. Research Center Rossendorf contributed to the experiment of SPE-4 by supplying needle shaped conductivity probes for the measurement of local void fractions in the primary circuit of the PMK-II test facility. In the course of the standard problem exercise No. 4 RCR contributed with post-test calculations using the thermalhydraulic code ATHLET.

The calculations showed, that the code was suitable to reproduce the main events of the test. Reasons for some deviations and modelling problems were discussed.