ML20127A943

Forwards Review of Seismic Hazard & Fragility in Limerick Generating Station Severe Accident Risk Assessment. Specific Recommendations for Improvement & Verification Encl

ML20127A943
Person / Time
Site:	05000000, Limerick
Issue date:	09/23/1983
From:	Knight J Office of Nuclear Reactor Regulation
To:	Rowsome F Office of Nuclear Reactor Regulation
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FOIA-84-624 NUDOCS 8310110473
Download: ML20127A943 (2)

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gaesa MEMORANDUM FOR:

F. Rowsome, Assistant Director for Technology, DST FROM:

James P. Knight, Assistant Director for Components & Structures Engineering DE o

SUBJECT:

REVIEW OF SEISMIC ELEMENTS IN THE LIMERICK GENERATING STATION SEVERE' ACCIDENT RISK ASSESSMENT (LGS-SARA)

We have completed our initial review of the seismic elements in the i

LGS-SARA. Specific recommendations for improvemer.t and verification of the LGS-SARA can de found. in each. chapter of the attached report. We find in general, that the LGS-SARA is a state-of-the-art probabilistic risk assessment whose limitations are primarily thJse inherent in the problem itself and it is currently beyond our means to. adequately address them.

We find, along with our consultant (Brookhaven National Laboratories).

that the resultart numerical estimates relating to seismically induced events may be most appropriately used in a relative rather than absolute manner. We also find that reliance upon simple point estimates to reflect actual risk is premature. However the wide bands of qcertianty can be used to gain insight as to the range of actual risk associated

-with seismic initiating events at Limerick. In addition the LGS-SARA.

affords evidence that the Limerick Generating Station Units 1 and 2 are capable of withstanding ground motion. oeyond the SSE and that there is no obvious weak link in their sei:.;nic design.

The branches and individual responsible for specific sections in the attached report are:

- Geosciences Branch ~(A. K. Ibrahim) - Seismic Hazard Q

- Structural and Geotechnical Engineering Branch (J. R. Pearring)-

Geotechnical Aspects

- Structural and Geotechnical Engineering Branch (N. C. Chokshi)-

Structural Fragility

- Mechanical Engineering Branch (Y. Li) - Component Fragility

- Equipment Qualification Branch (A. Lee) - Equipment Fragility This review was coordinated by L. Reiter,of the Geosciences Branch,

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James P.

ight, As istant Direct 5r for Component Structures Engineering Division of Eiigineering

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Enclosure:

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L. Reiter R. Jackson G. Lear R. Sosnak V. Noonan L Vollmer E. Sullivan A. K. Ibrahim J. P..Pearring N. C. Chokshi Y. Li A. Lee A. Thadani I

E.-Chelliah R. Martin L. Hulman F. Coffman A. Schwencer l'

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