ML19275A349

Responds to IE Bulletin 79-07.Response Spectrum Model Analysis Methods (a) and (B) & Time History Analysis Method (a) Not Used

ML19275A349
Person / Time
Site:	Satsop
Issue date:	08/02/1979
From:	Renberger D WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
NUDOCS 7910040154
Download: ML19275A349 (2)

Text

e EP y Worhington Public Power Supply System A JOINT OPERAllNG AGENCY

] P.O. Hon 968 3000 G r o. Wa sonNorom Way Hec ML a Mo. WasMiNGrom 9 9 3 5 2 PMohs (509) 375 5000 Docket No. C0-508 August 2, 1979 g7 50-509 G03-79-1455

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fluclear Regulatory Commission '

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c; Suite 202, Walnut Creek Plaza 1990 *i. California Boulevard Walnut Creek, CA 94F96 Attention: ffr. R.11. Engelken

Subject:

ilPPSS NUCLEAR PROJECTS fiOS. 3 & 5 IE BULLETIfl NO. 79-07

Dear !!r. En0elken:

In response to the subject bulletin, WPPSS submits the attached information for its projects llNP-3 and 5. Should you have any questions with regard to this response, please contact me.

Very trul y yours .

.Od OsMtp D. L. RENBERGER Assistant Director - Technology DLR:FJ:ds Attac hmen*,

1100 087 7910040 \ 6 h 79- 57

ATTACH!tEtlT

1) tione of the methods specified in IE-Bulletin 79-07, that is, Response Spectrum 11odel Analysis flethods (a) and (b) and Time History Analysis liethod (a) were used or will be used for WPPSS 3 and 5. C-E has never used al gebraic summation for combining the effects of horizontal and vertical seismic excitations.

2) This item is not applicable to llPPSS 3 and 5, in light of the answer to #1 above.

3) C-E computed separately for each of two horizontal and the vertical directions of seismic excitation, time histories of the six com[onents of force or moment (Fx, Fy, Fz, fix, fly, ft:') at various sections of the reactor coolant system main loop piping. The maximum codirectional components of force or moment over all time from each of the three directions of excitation were conbined by the square-root-of-the-sum-of-the-squares method to define the seismic loading condition at the particular piping location. The load sets thus defined were compared to, and shown to be less governing than, the seismic loading specified for design of the piping.

Since the combination of loads was performed af ter the completion of the dynamic analysis portion of the computation, appropriateness of the results of the combination was verified by direct observation of the uncombined inputs and the combined outputs.

The six components of force or moment (Fx, Fy, Fz, Mx, fly, f1z) at the supports and various sections of the Pressurizer Surge Line piping were computed separately for each of two horizontal and the vertical directions of seismic excitation by response spectrum dynamic analysis. The codirectional components of force or moment from each of the three directions of excitation were combined by the square-roo t-o f-the-sum-of-the-squares method to defi ne the seismic loading condition at the particular piping location. The load sets thus defined were compared to, and shown to be less governing than, the seismic loadings specified for design of the supports and piping.

The load combinations were calculated and verified by hand. The current version PIPESTRESS 2010 computer code, which is being used for analysis of the llPPSS 3 and 5 safety-related piping system in Ebasco scope, has been compared with selutions to sample programs generated by similar, independently written programs in the. public domain, i.e., AflSYS and PIPESD. This comparison which is documented in the liflP-3/5 PSAR Appendix 3.9.c, shows the PIPESTRESS 2010 results to be essentially the same as results generated by the above programs and by hand calculations.

4) Item (4) is not applicable to llPPSS 3 and 5 1100 088