ML20249B191

PNO-76-045:on 760317,reactor Was Shutdown Due to Abnormal Increase in Coolant Leakage Which Had Risen to 11.8 Gph.Insp of Piping Inside Drywell Disclosed Crack.Soft Patch Was Applied to Secure Leakage

ML20249B191
Person / Time
Site:	Humboldt Bay
Issue date:	03/18/1976
From:	Roy G, Thompson D, Warnick R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-76-045, PNO-76-45, NUDOCS 9806220153
Download: ML20249B191 (1)

Text

_-

~veme

(

o

,pMMVE)

. March 18, 1976 PRELIMINARY NOTIFICATION OF EVE!

R

U UAL CUR E

--PNO-76-45 W

This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance.

The information presented in as initially received without verification or evaluation

~

and is basically all that is knoun by OIE staff as of 4:00 p.m. on date of this notification.

IT S!!OULD BE SPECIFICALLY HOTED THAT THIS NOTIFICATION MAY CONTAIN INFOPJIAT]ON THAT LATER MAY BE DATERMINED TO BE INACCURATE OR' INCO: SISTENT. AN OFFICE OF INSPECTION AND ENFORCEMENT NOTIFICATION OF AN IUCIDENT OR OCCURRENCE (BLUE SHEET) SUBSEQUENTLY WILL BE ISSUED IF WARRAUTED.

Facility:

Pacific Gas & Electric Company Humboldt Bay Unit No. 3

Subject:

Crack in 2-Inch Diameter Suction Piping of Reactor Cleanup System A circumferential crack, approximately one inch in length, was found in the heat affected zone of a socket veld in the 2 inch diameter stainless steel suction piping of the reactor cicanup system. The reactor was shutdown at 0150 3/17/76 due to an abnormal increase in coolant leakage which had risen to 11.8 GPH. An inspection of piping inside the drywell during a subsequent hydrostatic test of the reactor coolant system disclosed the crack at approximately 7:00 pm on 3/17/76. A " soft patch" was applied to secure the leakage, which is unisolable from the reactor j

coolant system. An investigation of the problem and possible means of repair is underway by licensee personnel.

The technical specification limit for primary coolant Icakage is 1 gpm (60 gallons per hour).

A Region V inspector has been dispatched to the site.

It is expected that the Humboldt Plant will remain shutdown at least a week. The licensee and Region V are planning to issue press releases.

Hedia interest is expected in California because of awareness generated

/

j by the nuclear moratorium referendum.

Region V (Walnut Creek,.CA) received notification of this occurrence by telephon'e from the Plant Superintendent at 9:00 a.m. on March 18, f

1976.

Contact:

RFWarnick, IE x27261

GWRoy, IE x27261 DThompson, IE x27541

?

Distribution:

Chairman Anders Commissioner Mason S. J. Chilk, SECY Commissioner Gilinsky Commissioner Rowden G. F. Murphy, JCAE l

Commissioner Kennedy C. C. Kammerer, CA i

L. V. Gossick, J. C. Davis, OIE J. A. Harris, PA 1

B. C. Rusche, NRR J. La Fleur, ISP T. J. McTiernc7, AIA K. R. Chapman, NMSS H. K. Shapar, ELD l

Transmitted:

P Bldg 4 /f/[d H St M//f,,; MNBBh[r

/

Luge /h.((

I i

j2 PRELIMINARY NOTIFICATION - NOT FOR PUBLIC DISCLOSURE l

17 990&t20153 760318 PDR ISE PNO-76-045 PDR

-