Mark II Pressure Suppression Test Program, Phase II and III tests

Twenty-three blowdown tests were performed in Phases II and III of the Mark II Pressure Suppression Test program to evaluate pool dynamics effects in the Mark II containment geometry. The tests utilized the steam generator and drywell of the Pressure Suppression Test Facility (PSTF) and the Temporary Tall Test Tank (4T) as a combination suppression pool and wetwell air space. The vent geometry was a single 20-inch vertical pipe, which, with the earlier 24-inch data from the Phase I tests, yields a data set which approximates the range of pool to vent area ratios of all Mark II containments. Particular emphasis was placed on pool response to a simulated loss-of-coolant accident, including pool swell, wetwell pressurization, vent flow, pool thermal response, and chugging. Data correlations and phenomenological explanations of the observed data are included.