ML19256C887
| ML19256C887 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 07/23/1979 |
| From: | Bryan S, Klinger G, Nolan F NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| PNO-79-270A, NUDOCS 7910150652 | |
| Download: ML19256C887 (1) | |
Text
-
d4
~ - ' -
PRELIMINARY NOTIFICATION July 23, 1979 PPILIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-79-270A This oreliminary notification constitutes EARLY notice of an event of
(
POSSIBLE safety or public interest significance.
The information presented is as initially received without verification or evaluation and is basically all that is known by IE staff on this date.
l a cility:
Sacramento Municipal Utility District Rancho Seco Nuclear Power Plant Sacramento, California DN 50-312
Subject:
RESULTS OF ANALYSIS AND TESTING ON CLASS I PIPING SUPPORTS Update on PNO-79-170 - The results of the analysis of the 12 unanalyzed supports' identified in PNO-79-270 were reported to Region V on July 20, 1979.
The analyses showed 1 support having a safety factor greater than 5, 3 greater than 2 but less than 5, 5 greater than 1 but less than 2, 2 less than 1, and 1 still unanalyzed.
Both the "A" and "B" trains of the Decay Heat Removal System were affected with supports having safety factors less than 2.
As a result, Rancho Seco started reducing power operation at approximately 4:15 p.m. on July 20, 1979 in accordance with Technical Specifications for modification and repair of the pipe supports.
The plant was taken to hot shutdown and all pipe supports with safety factors less than a nominal 2 upgraded to a safety factor greater than 5.
Power operation was resumed on July 23, 1979.
There has been cinor media interest in this event.
Region V (San Francisco) was informed of this event by the Plant Super-intendent by telephone at approxicately 4:00 p.m. on July 20, 1979.
This information is current as of 8:30 a.m. en July 23, 1979.
Contact:
G. Klingler, IE x28019; F. Nolan, IE x28109; S. Bryan, IE x28019 Distribution:
Transmitted H St Chairman Hendrie Co::=issioner Bradford S. J. Chilk, SECY Coc issioner Kennedy Co=nissioner Ahearne C. C. Kammerer, CA Co==issioner Gilinsky ACRS (For Distribution) if Transmitted: MNBB P. Bldg 5 4 V. Stello, IE L. V. Gossick, EDO H. R. Denton, NRR Region 1 H. L. Ornstein, EDO R. C. DeYoung, NRR J. J. Fouchard, PA R. J. Mattson, NRR
~
N. M. Haller, MPA D. Vassallo, NRR (MAIL)
R. G. Ryan, OSP D. Eisenhut, NRR J. J. Cummings, OIA E. K. Shapar, ELD SS Bldg R. Minogue, SD k'. J. Dirchs, NMSS i4t7 279 S. Levine, PIS 1
PFILIMINAPI NOTIFICATION 1910150l h J
.