PNO-I-87-114, on 871207,reactor Scrammed from Approx 96% Power Due to Low Reactor Vessel Water Level.Caused by Malfunction of Feedwater Control Valves 13A & 13B.Preventive & Corrective Maint Underway

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PNO-I-87-114:on 871207,reactor Scrammed from Approx 96% Power Due to Low Reactor Vessel Water Level.Caused by Malfunction of Feedwater Control Valves 13A & 13B.Preventive & Corrective Maint Underway
ML20237A023
Person / Time
Site: Nine Mile Point Constellation icon.png
Issue date: 12/10/1987
From: Cook W, Jerrica Johnson
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
References
PNO-I-87-114, NUDOCS 8712140201
Download: ML20237A023 (1)


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DCS'No: 50220871207 Date: December 10, 1987 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-I-87-114 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by the Region I L staff on this date.

l Facility: Licensee Emergency Classification:

1 Niagara Mohawk Power Corporation Notification of Unusual Event Nine Mile Point Unit I Alert '

Scriba, New York Site Area Emergency Docket No. 50-220 General Emergency X Not Applicable

SUBJECT:

FORCED OUTAGE. GREATER THAN 48 HOURS.

At 00:54 a.m. on 12/7, the reactor scrammed from approximately 96 percent power on low reactor vessel water level. The cause of the low reactor water level was an apparent malfunction of both the Number 13A and 138 feedwater flow control valves. The licensee (control-room operator) attempted to manually override the No. 13B valve, which was causing 2-to-5 inch reactor vessel level oscillations, but was unable to prevent a reactor trip. As of 10:00 a.m. December 10, the licensee was still investigating the cause of the valve malfunctions.

In addition to troubleshooting the feedwater control valves, the licensee is conducting preventive and corrective maintenance and a primary containment inspection while the unit is shutdown. A unit startup is not projected until the end of this week.

The resident inspectors are onsite reviewing the licensee's actions. This PN is issued for information only. The State of New York has been notified.

Contact:

William Cook Jon Johnson  !

8-315-342-4041 488-1234 DISTRIBUTION:

H. St. MNBB Phillips E/W W111ste Mail: ADM:DMB c Chairman Zech EDO NRR NMSS DOT:Trans only Comm. Roberts PA OIA RES Comm. Bernthal OGC AE0D NRC Ops Crt i Comm. Carr Comm. Rogers ACRS Air Rights INPD---- l SECY SP NSAC----

CA 1 PDR. Regional Offices TMI Resident Section i RI Resident Office $

Licensee: '

(Reactor Licensees) f Region I Form 83 (Rev. August 1987) i I

0 .33 5712140201 871210 g' PDR ILE DCD O  !

p FNO-I-87-114

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