ML17296A387
| ML17296A387 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 05/25/1979 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| ANPP-13204-JMA, NUDOCS 7907090239 | |
| Download: ML17296A387 (4) | |
Text
P. O. BOX 2I666 PMOENIXp ARIZONA 85036 Docket Nos. 50-528,
- 529, 530 May 25, 1979 ANPP-13204-NfA/WFQ Mr. R. H. Engelken, Director U.
S. Nuclear Regulatory Commission Region V
202 Walnut Creek Plaza 1990 N. California Boulevard Walnut Creek, CA 94596
Subject:
NRC XE Bulletin 79-07, dated April 14, 1979 File:
D.4. 01. 1/79-005-026 P
Pr~r'wEll JUIX 3.
t919
/AC,'I 8
Dear Mr. Engelken:
We have reviewed the design of PVNGS in accordance with the concerns of NRC XE Bulletin No. 79-07 titled, "Seismic Stress Analysis of Safety-Related Piping".
Our responses are numbered the same as the bulletin item numbers and are as follows:
1.
None of the methods specified were used for the seismic analysis of safety related piping on PVNGS.
2.
Not applicable based on response //l.
3.
Piping computer programs for BOP and NSSS seismic stress analysis of safety related piping were verified as follows:
NSSS Time histories of the six components of force or moment (Fx, Fy, Fz; Mx, My, Mz) at various sections of the reactor coolant system main loop piping were computed separately for each of two horizontal and the vertical directions of seismic excitation.
The maximum codirectional components of force or moment over all time from each of the three directions of excitation were combined by the square-root-of-the-sum-of-the-square methods to define the seismic loading con-dition 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 piping.
Since the combination of loads was performed after 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.
g 907 090%5/@
0
Mr. R. H. Engelken U. S. Nuclear Regul ory Commission May 25, 1979 Page Two BOP The computer program has been verified using the following:
a.
ME-632, Computer Program, Seismic Analysis of Piping
- Systems, VERB MOD 8, 1976 Bechtel International Corpor-
- ation, San Francisco, California b.
Pressure Vessel and Piping 1972 Computer Programs Veri-fication, The American Society of Mechanical Engineers.
c.
Hand Calculations.
The computer program performs response spectrum analysis using standard normal mode analyses techniques.
Model combinations are done per Equation (4) of Regulatory Guide 1.92..
4.
Not applicable based on response //l.
This completes our response on the subject bulletin. If you have any further questions, please do not hes'itate to contact us.
Very truly yours, E.
E. Van Brunt, Jr.
APS Vice President, Nuclear Projects ANPP Project Director EEVBJr/WFQ/sb cc:
R. L. Robb J. A. Roedel W. M. Petro F.
W. Hartley W. H. Wilson C. Ferguson NRC Office of Inspection
& Enforcements Div. of Reactor Inspection Programs
'ashington, D.C.
20555