PKL tests on energy transfer mechanisms during small-break LOCAs

The Primarkreislaufe (PKL) test facility, originally designed to examine the refill and reflood phases of a loss-of-coolant accident, was modified and used for a series of transient and steady-state small-break tests. Results from these tests are presented with the intention of showing the influence of such parameters as power, reduce water inventories on the primary or secondary sides, and noncondensible gas on the ability of the system to remove decay heat. It is shown that in the case of a small break, the transport of decay heat from the system is ensured when a two-phase coolant mixture covers the core and energy can be removed from the secondary sides of the steam generators