Influence of the distribution of noncondensibles on passive containment condenser performance in PANDA

Recently, passive cooling systems have been designed for the long-term decay heat removal from the containment of Advanced Light Water Reactors. In particular, the long-term LOCA response of the Passive Containment Cooling System (PCCS) for the General Electric European Simplified Boiling Water Reactor (ESBWR) has been tested in the large scale PANDA facility. The PANDA tests achieved the dual objective of improving confidence in the performance of the passive heat removal mechanisms underlying the design of the tested systems and extending the data base available for containment analysis code qualification. The tests conducted subject the PCCS to a variety of conditions representing design-basis and beyond-design-basis accident conditions. These include operation in the presence of both heavier and lighter than steam noncondensible gases as well as a variety of asymmetric conditions and challenging start-up conditions. The present paper addresses the transient distribution of noncondensibles and their effect on the passive condenser performance in PANDA