PNO-II-96-075, on 961031,shutdowns Required by TS After C Battery Failed to Meet Required Capacity Criteria During Modified Performance Test.C Vital DC Bus cross-connected to a Battery.Decrease in Capacity Unexpected
| ML20138G317 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 10/31/1996 |
| From: | Wert L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| References | |
| PNO-II-96-075, PNO-II-96-75, NUDOCS 9610310205 | |
| Download: ML20138G317 (1) | |
October 31, 1996 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-96-075
.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 Region II staff in Atlanta, Georgia on this date.
Facility Licensee Emergency Classification Duke Power Co.
Notification of Unusual Event Mc Guire 1 Alert Cornelius, North Carolina Site Area Emergency Dockets: 50-369 General Emergency X Not Applicable Duke Power Co.
Mc Guire 2 Cornelius, North Carolina Dockets: 50-370
?
?
i
(
Subject:
SHUTDOWN DUE TO FAILURE TO MEET BATTERY CAPACITY CRITERIA l
Shutdown of McGuire Unit 1 was initiated at.9:00 p.m. on October 30.
Shutdown of Unit 2 began at 3:00 a.m. on October 31. The shutdowns were
-required by Technical Specifications (TS) after the "C" battery failed to meet the required capacity criteria during a modified performance test.
4 on October 28, 1996, McGuire conducted a modified performance discharge test of the "C" battery as required by TS. This battery is one of the four vital batteries at McGuire. The batteries are AT&T lead acid round l
cell batteries. TS 4.8.2.1.2.e requires the battery operability to be l
dsmonstrated by a capacity discharge test resulting in at least 80 percent capacity. The testing resulted in a demonstration'of 78.5 percent capacity. The licensee declared the "C" battery inoperable and entered into TS action statement 3.8.2.1.b.2 at 9:56 a.m. on October 28. This action statement allowed continued operation for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after the affected DC bus is connected to an operable battery. The "C" vital DC bus was cross-connected to the "A" battery.
The decrease in capacity was unexpected and indicated that the battery has degraded since installation in 1991. The licensee is currently developing plans to return the "C" battery to operability. Additionally, due to corcerns regarding the performance of the round cell batteries, the licensee is evaluating actions to demonstrate the operability of the other batteries.
The resident inspectors observed portions of the reactor shutdowns and will continue to monitor the licensee's actions.
This information is current as of 10:00 a.m. on October 31, 1996.
Contact:
L. WERT (404)331-5506 i
9610310205 961031 a
PDR I&E i
1