PNO-II-89-040, on 890530,rapid RCS Pressure Decreased to Less than 2,000 Psi.Licensee Investigating Incident to Determine Root Cause & Corrective Action.Anticipated That Unit Will Be Down for Approx 2 Wks

PNO-II-89-040:on 890530,rapid RCS Pressure Decreased to Less than 2,000 Psi.Licensee Investigating Incident to Determine Root Cause & Corrective Action.Anticipated That Unit Will Be Down for Approx 2 Wks

ML20247N635
Person / Time
Site:	Summer
Issue date:	05/30/1989
From:	Modenos L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-II-89-040, PNO-II-89-40, NUDOCS 8906050409
Download: ML20247N635 (1)

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May 30, 1989 b PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-89-40 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or

_public interest significance. The information is as initially received without verifi-cation or evaluation, and is basically all that is known by the Region II staff on this date.

FACILITY: South Carolina Electric & Gas Co. Licensee Emergency Classification:

'V. C. Summer Notification of Unusual Event Docket No. 50-395 Alert Jenkinsv111e, SC Site Area Emergency General Emergency X Not Applicable

SUBJECT:

INADVERTENT OPENING OF PRESSURIZE SAFETY VALVE At 02:54 a.m., C pressurizer safety valve opened resulting in a r&pid RCS pressure decrease.

When RCS pressure decreased to less than 2000 PSI the reactor operator manually tripped the ~

reactor and prepared to manually initiate safety injection. The safety valve reseated at approximately- 1900 PSI and RCS pressure was stabilized at approximately 2000 PSI. One

. steam dump valve failed to automatically close. Control air to the dump valve was promptly secured causing the steam dump valve to shut. The auxiliary feedwater flow was automatically initiated following the trip. Indicated flow to one of the three generators was approximately 10% less than expected. The unit was placed in cold shutdown to permit pressurizer safety valve replacement. The licensee is currently investigating this incident to determine root cause and corrective action. It is anticipated that the unit will- be down for approximately 2 weeks. The Senior Resident responded to the site and monitored licensee recovery activities. Resident and Regional Specialists are following this event. The Vendor Inspection Branch was contacted regarding followup on the safety valve issue. Information is current as of 1:00 P.m.

CONTACT: L. Modenos - 242-5619 DISTRIBUTION:

One White M' land Nat'l Flint North Bank Blds Regions MAIL TO: DCS (Original IE 34)

Chairman Zech ARM Region I DOT (Transportation Only)

Comm. Roberts OIA Region II Comm. Carr AE0D Region III FAX TO: INPO Comm. Rogers Region IV LICENSEE (Corporate)

Comm. Curtiss Region V RII Resident SECY OGC Nicholson Lane OCA' RES GPA/SLITP/PA EDO OI H Street NRR ACRS NMSS PDR 5520: //89 (a TO REGIONS AND HQ 0 09 g90530 "

}0 LIAY 69 L: 03 PND-II-89-040 PNU M