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A time-dependent human reliability analysis for a PWR (Pressurized Water Reactor) at shutdown

Conference ·
OSTI ID:6370790
Pressurized Water Reactors (PWRs) in the USA have experience numerous loss of residual heat removal (RHR) events during reactor shutdown and cooled down conditions. Of particular significance is the loss of the RHR system due to the inadvertent closure of the RHR suction valves on the lowering of the water level in the reactor vessel during required partially drained reactor coolant system (RCS) operations. Brookhaven National Laboratory (BNL) performed an assessment of the core damage frequency (CDF) due to loss of RHR events in an outage. The loss of RHR followed by failure of the operators to respond was found to be the dominant contributor to core damage. The objective of this paper is to present the human reliability model used to assess the associated human error probabilities (HEPs). The model includes determination of the time available for operator action as a function of the time after shutdown, partitioning of the time into a diagnosis phase and a recovery action phase, and assessment of the HEPs. The HEPs were then integrated into the loss of cooling event trees for CDF quantification. 7 refs.
Research Organization:
Brookhaven National Lab., Upton, NY (USA)
DOE Contract Number:
AC02-76CH00016
OSTI ID:
6370790
Report Number(s):
BNL-NUREG-41399; CONF-890405-3; ON: DE88013679
Country of Publication:
United States
Language:
English