Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1. Volume 5: Analysis of core damage frequency from seismic events during mid-loop operations
- Future Resources Associates, Inc., Berkeley, CA (United States)
- PRD Consulting (United States)
- EQE International, Inc., Irvine, CA (United States)
In 1989 the US Nuclear Regulatory Commission (NRC) initiated an extensive program to examine carefully the potential risks during low-power and shutdown operations. The program included two parallel projects, one at Brookhaven National Laboratory studying a pressurized water reactor (Surry Unit 1) and the other at Sandia National Laboratories studying a boiling water reactor (Grand Gulf). Both the Brookhaven and Sandia projects have examined only accidents initiated by internal plant faults--so-called ``internal initiators.`` This project, which has explored the likelihood of seismic-initiated core damage accidents during refueling shutdown conditions, is complementary to the internal-initiator analyses at Brookhaven and Sandia. This report covers the seismic analysis at Surry Unit 1. All of the many systems modeling assumptions, component non-seismic failure rates, and human error rates that were used in the internal-initiator study at Surry have been adopted here, so that the results of the two studies can be as comparable as possible. Both the Brookhaven study and this study examine only two shutdown plant operating states (POSs) during refueling outages at Surry, called POS 6 and POS 10, which represent mid-loop operation before and after refueling, respectively. This analysis has been limited to work analogous to a level-1 seismic PRA, in which estimates have been developed for the core-damage frequency from seismic events during POSs 6 and 10. The results of the analysis are that the core-damage frequency of earthquake-initiated accidents during refueling outages in POS 6 and POS 10 is found to be low in absolute terms, less than 10{sup {minus}6}/year.
- Research Organization:
- Nuclear Regulatory Commission, Washington, DC (United States). Div. of Safety Issue Resolution; Future Resources Associates, Inc., Berkeley, CA (United States); PRD Consulting, Idaho Falls, ID (United States); EQE International, Inc., Irvine, CA (United States)
- Sponsoring Organization:
- Nuclear Regulatory Commission, Washington, DC (United States)
- OSTI ID:
- 10183205
- Report Number(s):
- NUREG/CR-6144-Vol.5; ON: TI94018642; TRN: 94:018958
- Resource Relation:
- Other Information: PBD: Aug 1994
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
SURRY-1 REACTOR
REACTOR SHUTDOWN
SEISMIC EFFECTS
RISK ASSESSMENT
REACTOR FUELING
REACTOR ACCIDENTS
EARTHQUAKES
220900
210200
REACTOR SAFETY
POWER REACTORS
NONBREEDING
LIGHT-WATER MODERATED
NONBOILING WATER COOLED