ML20215J488

PNO-OSP-87-004:on 870429,approx 11,000 Gallons of Primary Coolant Water Spilled Into Containment Sump.Caused by Pressurizer Spray Line Vent Valve Which Had Been Left Open. Water Pumped from Sump to Radwaste Sys

ML20215J488
Person / Time
Site:	Sequoyah
Issue date:	05/04/1987
From:	Brady J, Mccoy F NRC OFFICE OF SPECIAL PROJECTS
To:
References
PNO-OSP-87-004, PNO-OSP-87-4, NUDOCS 8705080045
Download: ML20215J488 (1)

Text

_ _ _ _ _ _ _ _ _ _ _

l PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-0SP-87-04 5/4/87 l This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is

~

known by the Region II staff on this date. .

FACILITY: Licensee Emergency Classification:

Tennessee Valley Authority Notification of Unusual Event Sequoyah Units 1 Alert Docket Nos. 50-327 Site Area Emergency Soddy-Daisy, Tennessee General Emergency X Not Applicable

SUBJECT:

SPILL OF REACTOR COOLANT INTO CONTAINMENT Approximately 11,000 gallons of primary coolant water spilled into the contain-ment sump on April 29 while refilling the reactor vessel following completion of steam generator U-tube work.

The licensee began filling Unit I at 12:56 a.m. (EDT) and completed the operation at 4:40 a.m. (EDT). Operators began pressurizing the system to 350 pounds per square inch (psi) by continuing to charge water and reached 325 psi at 6:30 a.m.

Problems were encountered in getting pressure to increase further, and the licensee noted a 20 gallon per minute mismatch between charging and letdown flows. Personnel dispatched to containment found water spraying from a hose attached to the pressurizer spray line vent valve which had been used for venting during drain down and should have been closed for the fill operation.

The licensee began depressurization and sent auxiliary operators into contain-ment in wet suits to close the valve. This was accomplished by 9:00 a.m. (EDT).

The licensee indicated that the valve position had been checked prior to the fill operation. However, the NRC resident inspectors are looking into circum-stances associated with the event, particularly the adequacy of the licensee's checking of the valve.

The water was pumped from the sump to the radwaste system. No personnel contami-nrtion was reported, and no radioactivity was released to the environment as a result of this event.

The resident inspectors became aware of the leakage as a result of a routine review of the health physics log. The inspectors will look into why this incident was not formally reported. Media interest has occurred. The licensee made the information available to reporters by way of its media call-in tele-phone service.

The State of Tennessee has been informed.

This information is current as of 10:00 a.m. (EDT) on May 4, 1987, 0004 cCo , 492-5525 Nk00$004 J. Brady, 492-5554 PNO-OSP-87-OO4 PDR DISTRIBUTION:

H Street MNBB Phillips E/W Willste Mail Chairman Zech ED0 NRR 6S7 NMSS ADM:DMB Comm. Roberts PA Air Rights 0IA RES D0T: Trans Only Comm. Asselstine MPA NRR AE0D Applicable State 1$

Comm. Bernthal ES NRR Comm. Carr OGC INP0 SECY Regions: f h )g ACRS Licensee:  ;)p CA (Reactor Licenses)

POR Applicable Resident Site