ML19256C764
| ML19256C764 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 03/27/1979 |
| From: | Bryan S, Klinger G, Nolan F NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| PNO-79-064, PNO-79-64, NUDOCS 7910120440 | |
| Download: ML19256C764 (1) | |
Text
PRELIMINARY NOTIFICATION March 27, 1979 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-79-64 This preliminary 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 as of this date.
FACILITY: Virginia Electric and Power Company North Anna Unit 1 Dockee No. 50-338 Mineral, Virginia
SUBJECT:
POTENTIAL OVERSTRESS OF SAFETY RELATED PIPING CAUSED BY ACTUAL WEIGHT OF 6-INCH VELAN VALVES (ACTUAL WEIGHT DOUBLE DESIGN WEIGHT)
A reanalysis performed by Stone and Webster (S&W) of safety related piping on March 26, using correct weights for the 6-inch Velan check valves showed that low head safety injection piping to the hot leg of one of the three primary reactor coolant loops could be overstressed during a design basis earthquake.
S&W is rechecking their analysis with completion scheduled by noon today.
If the analysis is correct, the licensee stated that the plant will be shut down within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> to modify one pipe support and test the two related hangers. The licensee estimates 12 to 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> will be required to complete the modifications.
Media interest is expected.
The licensee plans to make a news release if he confirms that the overstress condition exists.
The NRC does not plan a news release.
The Commonwealth of Virginia has been informed.
Region II (Atlanta) received notification of this occurrence by telephone from the resident inspector at 6:15 p.m. on March 26. This information is current as of 9:00 a.m. on March 27.
Contact:
G. Klingler, IE x28019; F. Nolan, IE x28019; S. Bryan, IE x28019 Distribution:
Transmitted H St C. %
Chairman Hendrie Commissioner Bradford S. J. Chilk, SECY Commissioner Kennedy Commissioner Ahearne C, C. Kammerer, CA Commissioner Gilinsky (For Distribution)
Transmitted:
MNBB Ca $
P. Bldg \\1ir J. G. Davis, IE L. V. Gossick, ED0 H. R. Denton, NRR Region %
l'.3 3 H. L. Ornstei.1, ED]
R. C. DeYoung, NRR J. J. Fouchard, PA R. J. Mattson, NRR N. M. Haller, MPA V. Stello, NRR (fiAIL)
R. G. Ryan, OSP R. S. Boyd, NRR J. J. Cummings, 0IA H. K. Shapar, ELD SS Bldg l', Af R. fiinogue, SD g
W. J. Dircks, NMSS PRELIMINARY NOTIFICATION 1452 536 7910120gg f).
.