PNO-I-98-025, on 980630,unit 3 Established Reactor Criticality,However Reactor Was Shut Down When Control Room Operator Noticed Spiking Intermediate Range Monitor.Licensee Troubleshooting

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PNO-I-98-025:on 980630,unit 3 Established Reactor Criticality,However Reactor Was Shut Down When Control Room Operator Noticed Spiking Intermediate Range Monitor.Licensee Troubleshooting
ML20206R742
Person / Time
Site: Millstone Dominion icon.png
Issue date: 06/30/1998
From: Cerne A, Durr J
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
References
PNO-I-98-025, PNO-I-98-25, NUDOCS 9901200145
Download: ML20206R742 (1)


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June 30, 1998 l 1

PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-I-98-025 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 Region I staff in King of Prussia, Pennsylvania on this date.

Facility Licensee Emergency Classification Northeast Utilities Notification of Unusual Event Millstone 3 Alert Waterford, Connecticut Site Area Emergency Dockets: 50-423 General Emergency X Not Applicable

Subject:

MILLSTONE UNIT 3 CRITICALITY AND SUBSEQUENT SHUTDOWN I

Millstone Unit 3 established reactor criticality at 12:45 p.m. on June 30, 1998. However, at approximately 1:30 p.m., the reactor was shut down

-when control room operators noticed a spiking intermediate range monitor.

The licensee is currently troubleshooting this nuclear instrument. At this time, the licensee is not planning to restart the unit until day shift of. July 1, 1998. This was the first entry into Mode 2 since the unit was shut down on March 30, 1996 for operational and engineering problems. Subsequently, all three Millstone units were constrained from critical operations by NRC Orders, and required a Commission vote for restart. On June 15, 1998, the Commission authorized the restart of Unit 3, once the NRC staff agrees that appropriate pre-operational steps have been taken. At that time, the Commission transferred responsibility to the NRC Executive Director for Operations (EDO) for verifying all remaining restart related actions have been completed, including authorization to restart Unit 3. On June 29, 1998, the NRC Restart Assessment Panel (RAP) verified that the licensee completed all remaining restart related actions, including closure of relevant items of Inspection Manual Chapter 0350. After conferring with the RAP, the EDO j approved the authorization to restart Millstone Unit 3.

I The NRC staff is providing augmented inspection coverage of restart activities, including round-the-clock observations of licensee activities l during key operational evolutions. The licensee's power ascension program includes a planned self-assessment of performance at four intermediate hold points at approximately 30 percent, 50 percent, 75 i

. percent and 90 percent power. The NRC has confirmed that the licensee i

will discuss the results of these assessments with the staff, along with the disposition of any NRC concerns, prior to increasing power to the next hold point. The NRC will also review the company's 100 percent power level assessment before concurring that the restart and power ascension process has been successfully completed.

The NRC issued a press release on June 29, 1998, in conjunction with the I decision by the EDO to authorize Unit 3 restart. Various congressional, state, and local authorities and interested organizations had been 4 notified of the NRC restart decision.

Contact:

ANTONE CERNE JACQUE DURR (860)447-3170* (610)337-5224 9901200145 990630 PDR I4E -

PNO-I-99-025 PDR l u Off