PNO-V-88-008, on 880203,unplanned Start of Bruce Gm Diesel Generator a Occurred.Caused by Failure to Position Generator Control Switch While Performing Loss of Offsite Power Test. Further Startup Testing Suspended

PNO-V-88-008:on 880203,unplanned Start of Bruce Gm Diesel Generator a Occurred.Caused by Failure to Position Generator Control Switch While Performing Loss of Offsite Power Test. Further Startup Testing Suspended

ML20196C110
Person / Time
Site:	Rancho Seco
Issue date:	02/04/1988
From:	Dangelo T, Miller L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
References
PNO-V-88-008, NUDOCS 8802120246
Download: ML20196C110 (1)

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PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-V-88-08 Date 02/04/88

-.This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The infonnation presented is as initially received without verification or evaluation and is basically all that is known by Region V staff

'on this date.

FACILIT(: SACRAMENTO MUNICIPAL _ UTILITY DISTRICT Emergency Classification RANCHO SECO UNIT 1 Notification of Unusual Event DOCKET NO. 50-312- Alert HERALD, CA Site Area Emergency General Emergency X Not Applicable

SUBJECT:

SUSPENSION OF TESTING AT RANCHO SECO On February 3,1988, at 11:10 pm PST, with the unit in cold shutdown, while performing the "A-2" bus (TDI) Loss Of Offsite Power test (LOOP), the licensee failed to position a control power switch for the "A" Bruce GM diesel generator. The mispositioned switch caused an unplanned start of the "A" Bruce GM diesel generator upon performance of subsequent LOOP test steps. Rancho Seco has four safety related diesel generators. No loss of offsite power to the station or loss of decey heat removal resulted from the unplanned start of the one diesel generator. At this time the licensee does not believe any damage to the "A" Bruce GM diesel generator has occurred due to the short duration of operation. In addition, the licensee has discovered three additional problems during the LOOP test involving another mispositioned switch, a failure to start and a failure of n:rmal shutdown of the "A" TDI. The licensee has suspended further startup testing with the exception of required surveillance testing and HVAC testing until their investigation is complete. The resident inspectors are monitoring the licensee's investigation and corrective action.

The licensee is preparing a press release.

CONTACT: T. D'Angelo L. F H ' **"

209-748-2791 m ut.1 - 3 m

. DISTRIBUTION MADE BY 5520 T0: FAX T0:

Date Time Date Time Chairman Zech EDO RI INP0 p/y Com. Roberts AE0D RII NSAC c 1M Comm. Bernthal PA0 RIII LICENSEE 618 7 Comm. Carr SLITP RIV RESIDENT INSPECTOR 62'J 1

Comm. Rogers NRR HQS. OPERATIONS OFFICER (,J/g; SECY NMSS CA ARM MAIL TO:

POR 01 DCS(Original)

OGC OIA 00T:(Trans. Only Applicable State)

ACRS RES GPA RV FORM 211 Revised: 8/19/87 8802120246 880204 PDR '

-V 400 O \

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