PNO-II-96-083, on 961214,Unit 2 Shutdown Due to Small Amount of Backleakage Through Injection Sys Discharge Check Valve, Causing Gas Entrainment in B Train of RHR Sys.Nrc Resident Inspectors Observed Unit Shutdown & RHR Testing

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PNO-II-96-083:on 961214,Unit 2 Shutdown Due to Small Amount of Backleakage Through Injection Sys Discharge Check Valve, Causing Gas Entrainment in B Train of RHR Sys.Nrc Resident Inspectors Observed Unit Shutdown & RHR Testing
ML20132B222
Person / Time
Site: Catawba Duke Energy icon.png
Issue date: 12/16/1996
From: Carroll R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-II-96-083, PNO-II-96-83, NUDOCS 9612170104
Download: ML20132B222 (1)


I December 16, 1996 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-96-083 This preliminary notification constitutes EARLY notice of events of POSSIBLE cafety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by Region II staff in Atlanta, Georgia on this date.

Facility Licensee Emercency Classification Duke Power Co. Notification of Unusual Event Catawba 2 Alert York, South Carolina Site Area Emergency Dockets: 50-414 General Emergency X Not Applicable

Subject:

EXTENDED SHUTDOWN - CATAWBA UNIT 2 On December 14, 1996, Catawba Unit 2 was shutdown due to a small amount of backleakage through a safety injection system discharge check valve, which caused gas entrainment in the B train of the residual heat removal (RHR) system. The problem was identified during a routine test of the B RHR pump, which included operation in recirculation at low pressures.

Although the system was restored to an operable status, the licensee decided to shutdown the unit to more fully address the leaking check valve issue. Once in hot shutdown, the licensee was able to reseat the leaking check valve through the use of the safety injection check valve

  • test header. Restart was delayed, hcwever, due to the identification of a small weld leak on the component cooling water non-essential return header inside containment. Ultrasonic testing has indicated that there is a defect in the leaking weld.

Unit 2 is currently in hot shutdown, with preparations being made to put RHR in service and secure reactor coolant pumps in order to isolate and repair the component cooling water leak. Restart of the unit is not i

expected until later this week.

The NRC resident inspectors observed the unit shutdown and RHR testing, l and will continue to closely monitor the licensee's recovery activities.

The States of North and South Carolina have been notified. The licensee l is prepared to respond to any media inquiries, but no press release is planned.

This information is current as of 10:00 a.m., on December 16, 1996.

Contact:

R. E. CARROLL (404)331-5543 J

9612170104 961216 i PDR I&E PNO-II-96-083 PDR 17000 tE34 l

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