ML19263E707
| ML19263E707 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 05/25/1979 |
| From: | Eisenhut D Office of Nuclear Reactor Regulation |
| To: | Dunn C DUQUESNE LIGHT CO. |
| References | |
| NUDOCS 7906250070 | |
| Download: ML19263E707 (2) | |
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EN May 25,1979 Docket No. 50-334
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f1r. C. N. Dunn, Vice President Operaticns Division Ducuesne Light Company 435 Sixth Avenue Pittsburgh, Pennsylvania 15219
Dear Mr. Dunn:
The pu ;ose of this letter is to so our positicn regarding the use of soil structure interaction for the seismic Dipestress analyses being performed 'for Beaver Valley Power Station, Unit 1.
Based on the results of the information you provided by your letter dated May 23,1979 in response to our May 18, 1979 letter and in other meetings, we confirm that soil structure interaction methodology may be used for Seaver Valley proviced that seismic stresses calculated are increased by a factor of 1.2.
This factor applies to the seismic stresses derived from amplified response spectra for fundamental periods of 0.4 to 0.55 sec.
The earthquake of primary safety concern is the SSE.
However, due to the nonlinearities of the soil which are considered in the soil structure interaction analyses, the stiffness of the subgrade is a function of the earthcuake level.
Since the floor response spectra are sensitive to the stiffness of the subgrade, they too are dependent on the earthquake level. Therefore, it is requested that the following two points be addressed:
1.
Discuss in detail why it can be concluded that the piping analyzed for the SSE condition will safely withstand all earthquakes up to and including the SSE.
2.
For any piping systems which meet SSE requirements but do not meet the FSAR OBE design requirements, provide the level of earthquake for which the FSAR OBE design requirements are met.
Sincerely,
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See nex: page 2218 184 7906250 d 76
Mr. C. t1. Dunn Duquesne Lignt Company
. s-a cc: Geraic Charnoff, Esquire Mr. James A. Werling Jay E. Siloerg, Esquire Plant Superintencent Shaw, Pittman, Potts and Trowericge Beaver Valley Power Station 1300 M Street, N.W.
P. O. Box 4 Washington, D. C.
20036 Shippingport, Pennsylvania 15077 Karin Car er, Esquire Special Assistant Attorney General Bureau of Acministrative Enforcement 5th Floor, Executive House HarrisDur;, Pennsylvania 17120 Mr. J. 5. Cumiskey Stone anc Webster Engineering Corporation P. O. Box 2325 Soston, Massachusetts 02107 Mr. J. D. Woodwarc R & D Center Westingnouse Electric Corporation Building 7-303 Pittsburgn, Pennsylvania 15230 S. F. Jones '4emorial Library 653 Franklin Avenue Aliquippa, Pennsylvania 15001 Mr. Jack Carey Technical Assistant Ducuesne tight Company
?. O. Box 4 Shippingport, Pennsylvania 15077 Mr. R. E. Martin
~ Duquesne Light Company 435 Sixth Avenue Pitts urgn, Pennsylvania 15219 Marvin Fein Utility Counsel City of Pi ttscurgh 313 Ci ty-County Sui 1 1ing 1t sourgr. Dennsylvania 15219 3
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