PNO-V-88-023, on 880323,undervoltage Attachment of CRD Breaker Failed to Operate.Interference of Undervoltage Attachment Trip Lever W/Exterior Label Plate,Noted. Investigation Continuing

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PNO-V-88-023:on 880323,undervoltage Attachment of CRD Breaker Failed to Operate.Interference of Undervoltage Attachment Trip Lever W/Exterior Label Plate,Noted. Investigation Continuing
ML20148H204
Person / Time
Site: Rancho Seco
Issue date: 03/24/1988
From: Dangelo T, Miller L
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
References
PNO-V-88-023, PNO-V-88-23, NUDOCS 8803290351
Download: ML20148H204 (1)


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PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-V-88-23 Date 03/24/88 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information presented is as initially received without verification or evaluation and is basically all that is known by Region V staff on this date.

FAClLlTY: SACRAMENTO MUNICIPAL UTILITY DISTRICT Emergency Classification RANCHO SECO UNIT 1 Notification of Unusual Event DOCKET N0. 50-312 Alert i HERALD, CA Site. Area Emergency 1 General Emergency i X Not Applicable  !

SUBJECT:

BINDING 0F CONTROL R00 DRIVE BREAKER UNDERVOLTAGE ATTACHMENT The licensee informed Region V personnel on March 23, 1988 that the undervoltage attachment of the No. 3 Control Rod Drive Breaker (reactor trip breaker), a DC General Electric AK-2-25 breaker, had failed to operate properly while performing a routine  !

monthly surveillance of the breaker. The shunt. trip test of the same breaker did function properly, however.

The licensee performed preliminary toubleshooting of the breaker, without disassembly, and noted an interfer ance of the undervoltage attachment trip lever with an exterior label plate. In a briefing at 10:00 am PST, SMUD stated that the breaker would be sent to the vendor for a more complete inspection.

The licensee and Region V are continuing to investigate this occurrence. The licensee's actions in response to Generic Letter 83-28, "Required Actions Based on Generic Implications of Salem ATWS Events," and associated Bulletins and Temporary Instructions, had been previously reviewed and were considered acceptable.

CONTACT: L. Miller T. D'Angelo i FTS 463-3869 (209)748-2791 l DISTRIBUTION MADE BY 5520 T0: FAX T0- i Date Time Date Time Chairman Zech ED0 RI INP0 y;.r t i Comm. Roberts AE0D RII NSAC J:3 7 Comm. Bernthal PA0 RIII LICENSEE 9/% 2 Comm. Carr SLITP RIV RESIDENT INSPECTOR 9 #

Comm. Rogers NRR HQS. OPERATIONS OFFICER F.'f'.Z SECY NMSS CA ARM MAIL T0:

POR 01 DCS (Original) i OGC OIA D0T:(Trans. Only, Applicable State)

ACRS RES GPA RV FORM 211 8803290351 880324 Revised: 8/19/87 1 PDi< I&E PNO-V-88-023 DCD D({

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