Practical insights from implementing seismic probabilistic risk assessment and seismic margins assessment approaches
- Science Applications International Corp., Raleigh, NC (United States)
The Nuclear Regulatory Commission`s (NRC`s) guidance on performing the Individual Plant Examination For External Events (IPEEE) allows the implementation of a Seismic Probabilistic Risk Assessment (SPRA) or a Seismic Margins Assessment (SMA) to address the seismic portion of the IPEEE. The SPRA is a comprehensive approach which provides both quantitative and qualitative risk insights using an event tree/fault tree methodology. The SPRA results may include seismic core damage frequency, seismic plant damage state frequency, High Confidence of a Low-Probability-of-Failure (HCLPF) capacity, etc. The NRC guidance allows the use of the NRC SMA approach or the Electric Power Research Institute (EPRI) SMA to address the seismic IPEEE. Both SMA approaches apply limited scope reviews which focus on systems and equipment that have been found to be seismically risk significant based on results of earlier SPRA studies. The SMA results are expressed in terms of a plant HCLPF capacity. The EPRI SMA approach derives a plant HCLPF capacity based on a review of equipment in a success path model of safety systems and functions. The NRC SMA approach derives a plant HCLPF capacity based on a review of cutsets or minimal equipment/structural failure combinations that lead to core damage. The cutsets are generated from an event tree/fault tree solution of dominant core damage accident scenarios. The NRC`s A-46 issue can be efficiently addressed in parallel with the EPRI SMA evaluation. SAIC has implemented the systems analysis task for all three approaches on eight different nuclear power plants. This paper is intended to summarize the practical insights gained from actual application of all three NRC recommended approaches.
- OSTI ID:
- 170371
- Report Number(s):
- CONF-950740-; ISBN 0-7918-1343-6; TRN: 96:006323
- Resource Relation:
- Conference: Joint American Society of Mechanical Engineers (ASME)/Japan Society of Mechanical Engineers (JSME) pressure vessels and piping conference, Honolulu, HI (United States), 23-27 Jul 1995; Other Information: PBD: 1995; Related Information: Is Part Of Seismic engineering 1995. PVP-Volume 312; Ma, D.C. [ed.] [Argonne National Lab., IL (United States)]; Suzuki, K. [ed.] [Tokyo Metropolitan Univ., Hachioji, Tokyo (Japan)]; Aggrawal, M.L. [ed.] [and others]; PB: 470 p.
- Country of Publication:
- United States
- Language:
- English
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