ML20217H572
| ML20217H572 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 10/09/1997 |
| From: | Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-NUREG-CR-0098, RTR-NUREG-CR-98 97-547, TAC-L22113, NUDOCS 9710160146 | |
| Download: ML20217H572 (3) | |
Text
{{#Wiki_filter:. _ - _ _ _ - - _ _ _ _ Visu;isir EI. irs stic ANI IN m i:st Ct hil'A N Y l(irinuisis. VisuaNir 2326: October 9, 1997 United States Nuclear Regulatory Commission Serial No. 97 547 Attention: Document Control Desk NL&OS/MAE R1 Washington, D. C. 20555 Docket No. 72 16 Gentlemen: YlfLGJMIAILECTRIC AND POERfLCOMPANY l NO. RTH ANNAJRD_EEEMDEUISSPENT FQEL_SIOBAGE INSTALLATION (LSES1) l LLQUEEARTION ANALY_SISEAC NO.J.2;L113) l Virginia Electric and Power Company (Virginia Power) submitted an application for the revlow and approval of a site specific license for an independent spent fuel stora00 installation (ISFSI) at North Anna Power Station on May 9,1995 (Serial No. 95-195). During a rnoeting on May 5,1997, with the NRC, a question was raised concoming the use of NUREG/CR 0098, Development of Criteria for Seismic Review of Selected Nuclear Power Plants, dated May 1978, as part of the liquefaction analysis. Our basis for the use of NUREG/CR 0098 is attached. Please contact us if you have any questions or require additional information. Very truly yours, w James P. O'Hanlon Senior Vice President - Nuclear ) Attachment Commitments made by this letter: None cc: Mr. J. W. Shea I Office of Nuclear Material Safety and Safeguards 70{' U. S. Nuclear Regulatory Commission, Mail Stop 0 6 G-22 [gd Washington, D. C. 20555 Mr. M. J. Morgan NRC Senior Resident inspector North Anna Power Station ~{ppoi ?u 't8b 3 8 %88 % llllTll%Ilyl!I[EllIllIII e eon
ATTACHMENT 1 Llquefaction Analysis NRC Ouestion: What is the basis for using NUREG/CR 0098 as pt t of the liquefaction analysis? Virginia Power Response: NRC Generic Letter 88-20, Supplement 4,* requested all U.S. nuclear plants to examinq the effects of several specific extemal events. This request was termed Individual Plant Examination of Extemal Events (IPEEE). An attachment to the generic letter, NUREG 1407,* provided guidance for the implementation of IPEEE. NUREG-1407 recommended that one of the two following methods be used to accomplish the IPEEE evaluation for the seismic event: 1) Seismic Probabilistic Risk Assessment, or
- 2) the Electric Power Research Institute (EPRI) or NRC Seismic Margins Method.
l Virginia Power chose to perform IPEEE-Seismic for North Anna Power Station utilizing the EPRI Seismic Margin Methodology. Since North Anna was characterized in NUREG 1407 as a focused scope plant, this required a review of the seismic performance of plant and components under a review level earthquake anchored at 0.3g peak ground acceleration (pga). The EPRI Seismic Margin Method requires parforming the IPEEE review using a realistic, median centered ground cpectral shape c accordance with NUREG/CR-0098.* This ground spectrum, with 0.39 pga, was used for North Anna Power Station and plants with similar earthquake intensities for performing IPEEE seismic. Therefore, the shape of the soll spectrum used in the liquefaction analysis was based on NUREG/CR-0098, as stated in the report"' submitted by Virginia Power. As verified by results of soil test borings and rock cores performed in July 1994 at thu North Anna ISFSI site, the soils encountered are similar in composition, consistency, and stratigraphy to the soils present at the main plant, service water reservoir, and main dam sites. The soils at each location evolved from the in place weathering of the parent rock. Figure 2.5-1, Site Geologic Map, contained in the SAR, shows that the same parent rock underlies this entire area. In addition, tests peiformed on soil samples obtained at the ISFSI site confirm that the soils exhibit similar properties to those soils previously analyzed at other locations throughout the station. The 0.3g soil response spectrum curve for IPEEE seismic completely envelopes all points on the 0.18g curve for the ISFSI design basis earthquak 'OBE). As stated in section 2.5.4 of the SAR, liquefaction will not occur at North Anna i wer Station under a 0.30g earthquake as determined for IPEEE seismic, it is therefore concluded that liquefaction will not occur for the DBE of 0.18g for the ISFSI. Page 1 of 2 J
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References:
l l
- 1. Generic Letter 88 20, Individual Plant Examination of Extemal Events (IPEEE) for Severe Accident Vulnerabilities 10 CFR 50.54 (!), Supplement 4, dated June 28,
- 1991,
- 2. NUREG 1407, Procedural _ and Submittal Guidance for the Individual Plant Examination of Extemal Events (IPEEE) for Severe Accident Vulnerabilities, dated June 1991.
- 3. NUREG/CR 0098, Development of Criteria for Seismic Review of Selected Nuclear Power Plants, dated May 1978.
- 4. Martin, J. R., December 1994; Soil Failure / Liquefaction Susceptibility Analysis For North Anna Power Station Selsmic Margin Assessment.
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