BWR STANDBY COOLING HEAT TRANSFER PERFORMANCE UNDER SIMULATED LOSS-OF-COOLANT CONDITIONS BETWEEN 15 AND 300 PSIA

摘要

Tests were conducted to determine the heat transfer effectiveness of the General Electric emergency cooling systems at pressures up to 300psiA. A full-scale, electrically heated, stainless steel-clad heater bundle was used to simulates fuel bundle. Bottom flooding and top spray transient tests were performed under loss-of-coolant conditions.nThe thermal response of the cladding is reported. Individual local heat transfer coefficients were calculated as a function of location, time and the various test parameters. The variation of the coefficients provides insight into the heat transfer mechanisms significant during the emergency cooling phase of the postulated loss-of-coolant accident. Increasing the system pressure above atmospheric pressure improved the performance of both the bottom flooding and the top spray modes of emergency cooling. The time required for the cladding to cool to saturation temperature in the flooding mode and the maximum cladding temperatures in the spray mode were both significantly reduced as pressure was increased to 200 psia.