Dr. Sang Lung Chan
Swiss Federal Institute of Technology Zurich, Switzerland.

Speech title: Gap Cooling Mechanism Associated with Three Mile Island Unit 2 (TMI-2) –LIKE Accident

Abstract: In this presentation various models of debris-to-vessel gap cooling will be explored. The gap cooling mechanism is explained by the water ingression through the gap between the debris and reactor vessel. This gap cooling mechanism is essential to demonstrate the integrity of the lower head (LWH) of the Three Mile Island Unit 2 (TMI-2) during the accident. The assessment of SCDAP/RELAP5/MOD3.3 (S/R5/M3.3) to model the TMI-2 like accident has been studied in [1,6,7]. It was shown that without considering the gap cooling mechanism, S/R5/M3.3 model of the TMI-2 accident failed to explain the conservation of the TMI-2 LWH.