2CAN079401, Informs That Util Intends to Complete Seismic IPEEE for ANO Unit 2 at Reduced Scope Level of Effort,As Requested by GL 88-20,Suppl 4

Informs That Util Intends to Complete Seismic IPEEE for ANO Unit 2 at Reduced Scope Level of Effort,As Requested by GL 88-20,Suppl 4

ML20070J543
Person / Time
Site:	Arkansas Nuclear
Issue date:	07/20/1994
From:	Mims D ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
2CAN079401, 2CAN79401, GL-88-20, TAC-M83589, NUDOCS 9407250170
Download: ML20070J543 (2)

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OOerations u w :.m v.n July 20,1994 2CAN079401 U. S. Nuclear Regulatory Commission Document Control Desk Mail Station PI-137 Washington, DC 20555

Subject:

Arkansas Nuclear One - Unit 2 Docket No. 50-368 L.icense No. NPF-6 Scope Reduction for Seismic Individual Plant Examination of External Events, Generic Letter 88-20, Supplement 4 (TAC No. M83589)

Gentlemen:

By letters dated December 19, 1991 (OCAN129101) and September 18, 1992 (OCAN099201), Entergy Operations committed to conduct a seismic individual plant examination of external events (IPEEE) as requested by Generic Letter 88-20, Supplement 4 for Arkansas Nuclear One (ANO). Supplement 4 to Generic Letter 88-20 categorized the ANO-2 seismic review as a " focused scope" evaluation. By letter dated June 18,1992 (OCNA069212), the Staff found our selected IPEEE methods acceptable.

Draft NUREG-1488, " Revised Livermore Seismic Hazard Estimates for 69 Nuclear Power Plant Sites East of the Rocky Mountains," was recently issued by the NRC. This NUREG provides signi6 cant new information relative to large reductions in the seismic hazard at eastern United States plants. Specifically, thes, revised Livermore results have confirmed that the mean seismic hazard at ANO-2 is lowc/t han originally estimated. The ANO-2 mean seismic hazard is lower than the 1989 Livermore mean seismic hazard estimates for the group of plants which were originally designated as "reducca scope" for the seismic IPEEE. A detailed evaluation of the impact of the new Livermore results was provided to the Staff by the Nuclear Energy Institute on April 5,1994, in a white paper entitled " Justification for Reduction in IPEEE Program Based on Revised LLNL Seism.c IIazard Results."

Based on this revised information, Entergy Operations believes that the current understanding of seismic hazards no longer justifies a " focused scope" type evaluation for the ANO-2 seismic IPEEE. Also, the walkdown requirements for a reduced scope program are the same rigorous requirements used for the full or focused scope seismic reviews that will effectively capture the seismically weaker elements which require modifications. Therefore, Entergy Operations intends to complete the seismic evaluation I,. o -

for.ANO-2 at the " reduced scope" level of effort. Entergy Operations estimates that this 940725017o 94o720 g I 9

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, July 20,1994 2CAN079401 Page 2 scope reduction commitment change will save approximately $120,000 due to a reduction in soils evaluations and high confidence of low probability of failure calculations and therefore,is considered a cost beneficiallicensing action. Should you have any questions regarding this submittal, please contact me.

Very truly yours, db;[YC.7)L,,;

Dwight C. hiims Director Licensing DChi/nbm  ;

cc: hir. Leonard J. Callan Regional Administrator U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 NRC Senior Resident Inspector Arkansas Nuclear One - ANO-1 & 2 Number 1, Nuclear Plant Road Russellville, AR 72801 hir. George Kalman NRR Project hianager Region IV/ANO-1 & 2 U. S. Nuclear Regulatory Commission NRR hiail Stop 13-H-3 One White Flint North 11555 Rockville Pike Rocksille, hiD 20852 hir. Roy Zimmerman CBLA Task Force U. S. Nuclear Regulatory Commission NRR hiail Stop 12-D-22 One White Flint North 11555 Rockville Pike Rockville, hfD 20852 hir. hiehdi Sarram Nuclear Energy Institute 1776 I Street NW Suite 400 Washington, DC 20006-3708

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