High Pressure Core Spray (HPCS) System

The HPCS is used in BWR-5 and BWR-6 boiling water reactor designs. The HPCS system consists of a single motor-driven centrifugal pump located outside primary containment, an independent spray sparger in the reactor vessel located above the core, and associated piping, valves, controls, and instrumentation. The system is designed to operate using normal offsite auxiliary power. Should a loss of offsite power occur, a dedicated backup source of power is available from a diesel generator. The backup source of power (diesel generator) only affects the unreliability of the HPCS system when a loss of offsite power occurs as an initiator or during an HPCS system demand.

The primary function of the HPCS system is to maintain reactor vessel inventory for line breaks up to 1-in. nominal size. The HPCS system also provides spray cooling heat transfer during breaks in which uncovering of the core is assumed. The HPCS system pumps water through a peripheral ring spray sparger mounted above the reactor core and can supply coolant over the entire range of system operation pressures.

The initial system study is documented in "High-Pressure Core Spray System Reliability,1987-1993" (NUREG/CR-5500, Volume 8 ). The links below provide the current information for the study and latest results.

Current Results (SPAR-based):

Historical Results (SPAR-based):

Historical Results (LER-based):

Supporting Information:

Page Last Reviewed/Updated Monday, October 24, 2022