PNO-V-91-016, on 910808,transmitter on Volume Control Tank Failed.Level Transmitter Repaired.Licensee Conducting Confirmatory Testing of Transmitter

From kanterella
Jump to navigation Jump to search
PNO-V-91-016:on 910808,transmitter on Volume Control Tank Failed.Level Transmitter Repaired.Licensee Conducting Confirmatory Testing of Transmitter
ML20203C622
Person / Time
Site: San Onofre Southern California Edison icon.png
Issue date: 08/09/1991
From: Johnson P, Johnston K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
References
PNO-V-91-016, PNO-V-91-16, NUDOCS 9712150369
Download: ML20203C622 (1)


.

n r,-is '91 1m mist in:mna 33a6 Fat 4927142 TFL to:ral-a9;-?la? t:m3 Pos pp if;lv.< .m (e " pv J. IL /b[c.

MINARY NOTir! CATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-V-91-16 Date: 8/9/91 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information presented is as initially received cithout verification or evaluation and is basically all that is known by Region V staff on this date.

FACILITY: SOUTHERN CAllf0RNIA ED N Emergency Classification San Onofre Unit 1 1 X Notification of Unusual Event Docket No.60-206 6 ~~ ~ Alert San Clemente, California 451te Area Emergency General Emerganqy

$OO Not Applicable

SUBJECT:

INITIATION OF REACTOR SHU100WN DCCAUSE OF TAILED LEVCL TRANSHITTER The licensee determined at F:00 p.m. (all times pDT) on August 8,1991 that one of two level transmitters on the volume control tank (VC1) was inoperable. On low VCT 1: vel, the transmitters act to initiate transfer of the charging pump suction path from the VCT to the refueling water storage tank. Both transmitters are required by the Technical Specifications (TS) to be operable. Since the T5 did not specifically permit one of the transmitters to be out of service for maintenance for even a limited period of time, inoperability of one transmitter required the licensee to enter TS 3.0.3. This TS requires a shutdown to be initiated if the problem cannot be corrected within one hour.

he licensoo contacted the NRC to request a waiver to the TS, to permit repair of m level transmitter. A unit shutdown was initiated at 6:00 p.m., pending the tcome of the waiver request, and an Unusual Event (UE) was declared at that time.

ho licenseo terminated the UE at 7:?2 p.m., af ter the power reduction was initiated. After discussion of the waiver request with the li",ansoe, and with the concurrence of Region V. NRR approved a waiver of compliance at 8:17 1.m., allowing the licensce 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to repair the level transmitter before a unit slutdown would be required. The licensee terminated the power reduction at 8:18 p.m. at a power level o 78%, and resumed operation at nominal full (91%) power. The level trans-mitter was repaired later on the evening of August 8; although confirmatory testing is still being conducted, the transmitter presently appears to be operating properly.

The resident inspectors are following the licensee's activities.

The licensec notified state and local officials regarding declaration of the UE.

The licensee also issued a press release, and limited media interest has resulted.

This information is current as of 10:00 a.m. on August 9, 1991.

CONTACT: K. Johnetnn P. Johnson TTS 408-0354 FTS 400-0300

} {? V v

q) "

l.li i II,;  :. 1:l.l .

9712t50369 910009 PDR 1&iE PNO-V-91-016 PDR .