Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1. Volume 5: Analysis of core damage frequency from seismic events for plant operational state 5 during a refueling outage

Technical Report · Mon Aug 01 04:00:00 EDT 1994

DOI:https://doi.org/10.2172/10183202· OSTI ID:10183202

Budnitz, R J ^[1]; Davis, P R ^[2]; Ravindra, M K; Tong, W H ^[3]

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1. Future Resources Associates, Inc., Berkeley, CA (United States)
2. PRD Consulting (United States)
3. 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 Sandia National Laboratories studying a boiling water reactor (Grand Gulf), and the other at Brookhaven National Laboratory studying a pressurized water reactor (Surry Unit 1). Both the Sandia and Brookhaven 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 outage conditions, is complementary to the internal-initiator analyses at Brookhaven and Sandia. This report covers the seismic analysis at Grand Gulf. All of the many systems modeling assumptions, component non-seismic failure rates, and human effort rates that were used in the internal-initiator study at Grand Gulf have been adopted here, so that the results of the study can be as comparable as possible. Both the Sandia study and this study examine only one shutdown plant operating state (POS) at Grand Gulf, namely POS 5 representing cold shutdown during a refueling outage. 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 POS 5. The results of the analysis are that the core-damage frequency for earthquake-initiated accidents during refueling outages in POS 5 is found to be quite low in absolute terms, less than 10{sup {minus}7}/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: 10183202
• Report Number(s): NUREG/CR--6143-Vol.5; ON: TI94018641
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210100
22 GENERAL STUDIES OF NUCLEAR REACTORS
220900
FAILURE MODE ANALYSIS
GRAND GULF-1 REACTOR
GRAND GULF-2 REACTOR
POWER REACTORS
NONBREEDING
LIGHT-WATER MODERATED
BOILING WATER COOLED
REACTOR ACCIDENTS
REACTOR FUELING
REACTOR SAFETY
REACTOR SHUTDOWN
RISK ASSESSMENT
SEISMIC EFFECTS