PNO-V-88-014, on 880219,inadvertent Safety Injection Actuation Occurred While Testing of Actuation Logic Matrix Was in Progress & W/Unit at 100% Power.Unit Stabilized W/O Complication & Safety Injection Components Restored

PNO-V-88-014:on 880219,inadvertent Safety Injection Actuation Occurred While Testing of Actuation Logic Matrix Was in Progress & W/Unit at 100% Power.Unit Stabilized W/O Complication & Safety Injection Components Restored

ML20196E332
Person / Time
Site:	San Onofre
Issue date:	02/22/1988
From:	Johnson P, Tatum J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
References
PNO-V-88-014, PNO-V-88-14, NUDOCS 8803010038
Download: ML20196E332 (1)

d9.

PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-V-88-14 Da 2/22/88 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or

-public interest significance. The information presented is as initially received without vr.rification or evaluation and is basically all that is known by Region V staff on.this

'date.

FACILITY: SOUTHERN D LIFORNIA EDIS0N Emergency Classificatiun SONGS UNIT 3 Notification of Unusual Event DOCKET N0. 50-362 Alert SAN CLEMENTE, CA Site Area Emergency _

General. Emergency T Not Applicable

SUBJECT:

SAFETY INJECTION ACTUATION AND OUTAGE GREATER titan 48 HOURS At 1:04 p.m. on February 19, 1988, an inadvertant safety injection actuation occurred while t'; sting of the actuation logic matrix was in progress. The unit was at 100% power at the time of the event. All safety injection components ectuated properly, but no water was injected except for the amount contributed for a short period by additional charging flow.

Th; operations staff manually tripped the unit as prescribed by plant procedures for inadvertent safety injection actuation. The unit was stabilized without complication following the reactor trip, and safety injection components were restored to standby.

During extensive troubleshooting on February 19 through 21, the licensee was not able to rcpeat the event or conclusively identify the cause. Principal suspicion centered on the

~

matrix test pushbt.tton and the test power supply, since these are components which affect more than one logic train. A slightly loose terminal was found on each (screw tightened 1/2 turn on the test pushbutton and 3/4 turn on the test pcwer supply on/off switch), but no other clear indication could be found. The licensee also replaced the matrix test pushbutton for further bench testing, which was not conclusive. The test pushbutton will be sent to a consultant's test laboratory for further examination. Inspection and continuity

-ch;cks of related circuitry also produced no findings.

The licensee repeated the safety injection matrix testing on February 21, completing it without further complication. The reactor was taken critical again at 11:41 p.m. on February 21, and synchronized with the grid at 5:14 a.m. on February 22. As of 8:00 a.m. on February 22, the unit was at 20% power.

This information .

[rentasof8:00a.m.PSTonFebruary 22, 1988.

Contact:

P. >n J. Tatum (FTS) 63-3745 (714) 492-2641 DISTRIBUTION BY 5520: FAX T0:

Date A /M Time /o'.Jo Date Time Chairman Zech EDO RI INP0 /'v/

Com. Roberts AE00 RI! NSAC /3 9 Comm. Bernthal PA0 RIII LICENSEE V,'22.

Com. Carr SLITP RIV RESIDENT INSPECTOR FW Comm. Rcgers NRR HQS. OPERATIONS OFFICER / W

'SECY NMSS-CA ARM MAIL T0:

PDR 01 DCS (Original)

OGC. 01A D0T:(Trans. Only, Applicable State)

ACRS RES GPA 8803010038 880222 RV FORM 211  :

gyg g Revised: 8/19/87 16-JV