ML051460302

U.S. Nuclear Regulatory Commission Operations Center Event Report

ML051460302
Person / Time
Site:	Millstone
Issue date:	04/27/2005
From:	- No Known Affiliation
To:	Office of Nuclear Reactor Regulation
References
FOIA/PA-2005-0207
Download: ML051460302 (4)

Text

4.

, 1 04/27/2005 U.S. NuclearRegulatory Commission OperationsCenter Event Report Paire I Power Reactor Event# 41607 Site

MILLSTONE Notification Date/ Time: 04/17/2005 09:23 (EDT)

Unit: 3 Region: 1 State: CT Event Date/ Time: 04/17/2005 08:42 (EDT)

Reactor Type: [1] GE-3,[2] CE,[3] W-4-LP Last Modification: 04/17/2005 Containment Type: MARK I DRYAMB DRYSUB NRC Notified by: MICHAEL GOBELI Notifications: SAM COLLINS RA HQ Ops Officer: JOHN KNOKE TIM MCGINTY IRD Emergency Class: ALERT JIM DYER ET 10 CFR Section: R1 BLAST DIAL 50.72(a) (1) (i) EMERGENCY DECLARED E.BRENNER PAO 50.72(b)(2)(iv)(A) ECCS INJECTION THOMAS NRC 50.72(b)(2)(iv)(B) RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) VALID SPECIF SYS ACTUATION Unit Scram Code RX Crit linitPower Initial RX Mode Curr Power I Current RX Mode 3 AR Yes 100 Power Operation 0 Hot Standby ALERT DECLARED DUE TO UNIT 3 MAIN STEAM RELIEF VALVES NOT RESEATING AFTER ACTUATION At 09:23 the licensee indicated that several Main Steam Relief Valves lifted and stayed open. A high pressure flow signal from the secondary Steam Generator caused initiation of Unit 3 Safety Injection, which in turn caused the Reactor to trip. All rods fully inserted as required. Activation of the Safety Injection subsequently caused the Pressurizer level to go solid. About 30 minutes into the event the primary Reactor Coolant and Main Steam Systems stabilized, including the Pressurizer level and pressure. During the initial briefing, about 09:35, the licensee reported that all secondary Safety Relief Valves have reseated. Decay heat is being directed to the Atmospheric Dumps due to the Main Condenser not being available. The licensee is attempting to establish ERDS.

Initial assessment of this incident is believed not to be security related, however, follow-up is being conducted to verify same. At 09:48, NRC management made a decision to enter into Monitoring Mode. At about 11:15 the licensee indicated that a valve in the Charging System indicated some leakage, therefore it was isolated. Licensee stated that no radiological releases and no S/G tube leakage was indicated.

Licensee notified State and local emergency response agencies. They will notify the NRC Resident Inspector.

Notified DHS (Doyle), FEMA (Biscue), DOE (Smith), USDA (Magners), and HHS (Hogan).

• • • UPDATE FROM D. DODSON TO W. GOTT 1328 EDT 04/17/05 *

"At approximately 0830 on April 17, 2005 Millstone Unit 3 experienced an automatic reactor trip from full power.

The Reactor is in a stable shutdown condition and is proceeding to Mode 5 cold shutdown. No release of radioactivity other than those minor releases associated with normal plant operation has occurred. There were no personnel injuries associated with the event.

"In addition to the Reactor Trip, half-train Safety Injection (SI) and half-train Main Steam Isolation (MSI) tons

0412712005 U.S. NuclearRegulatory Commission Operations Center Event Report Pie2 Power Reactor Event # 41607 occurred. Control room personnel were successful at manually initiating full SI and MSI. SI has since been terminated and RCS pressure control has been restored. Multiple steam line safety valves (MSSV) lifted with at least one MSSV indicating a failure to reclose. As a result, an ALERT was declared at approximately 0853 due to the failure of at least one MSSV failing to reclose. All MSSVs are currently closed. Auxiliary Feedwater (AFW) actuated automatically as expected, however, the turbine driven auxiliary feedwater pump (TDAFWP) tripped on start-up and was subsequently reset locally. Both motor driven auxiliary feedwater pumps (MDAFWPs) operated as expected to maintain steam generator water levels. Due to the additional inventory injected to the Reactor Coolant System (RCS) as a result of the SI actuation, the pressurizer filled and a primary system safety valve (PSSV) actuated at a lower than expected pressure. All PSSVs are currently closed, however, there is indication of leakage past either a PSSV or Pilot Operated Relief Valve (PORV). Upon alignment of the Charging system to Refueling Water Storage Tank recirculation flow path, 2 valves had indication of packing leakage. Those packing leaks have been terminated.

"The cause of the event is under investigation."

The licensee has issued a press release. The licensee will notify the NRC Resident Inspector.

Notified R1 DO (J. White) and IRD Manager (T. McGinty)

• *

• UPDATE FROM D. DODSON TO W. GOTT AT 1915 ON 04117/05 * *

"The previously reported time of the Alert declaration should be corrected to read 08:42. Millstone Unit 3 entered Mode 4 [Hot Shutdown] at approximately 19:03 on April 17, 2005. The event at Millstone Unit 3 was terminated at 19:05. The cause of the event is under investigation. A recovery plan is being formulated."

Internal NRC notifications, DHS (Frost), NRC/EPA (Threatt), FEMA (Erwin), DOE (Morone), USDA (Smeltzer),

HHS (Desi)

The licensee will notify the NRC Resident Inspector.

At 23:45 the Agency exited Monitoring Mode and entered into Normal Mode.

04/27/2005 Pace 1 Event Response Mode and Emergency Class Log Event: 41607 Type: POW Notify Date / Time: 4117/05 09:23 EDT Site: MILLSTONE Retract: m EventDate/Timne: 4/17/05 08:42 EDT Data Type Viassification Entry Date/Tinte Exit Date/Time EMERGENCYCLASS ALE 4/17/05 08:42 4/17/05 19:05 RESPONSE II MONITORING 4/17/05 09:48 4/17/05 23:45

0412712005 Paye I Event Timeline

!!! This is a draft document; do not release to the public III Event: 41607 Type POW Notify Date/ Time: 4/17/05 09:23 EDT Site: MILLSTONE Retract: El Event Date / Tize: 4/17105 08:42 EDT Entry Date Entry Thne Timeline Text 17-Apr-05 08:29 Reactor Trip and Safety Injection (SI). MSIVs closed. Several main steam safety valves (MSSV) lifted.

Primary safety lifted and then reseated.

17-Apr-05 08:42 Millstone 3 declared an Alert.

17-Apr-05 09:53 NRC entered Monitoring Mode.

17-Apr-05 09:53 NRC requests licensee to Initiate ERDS.

17-Apr-05 10:10 Dominion having difficulty In establishing ERDS.

17-Apr-05 10:54 AFW turbine started then tripped and then restarted manually. Feeding with three aux feed pumps.

17-Apr-05 11:05 No evidence of tampering. Established normal charging (pressurizer level 64%). Dominion staffing EOF.

Pressure control using Atmospheric Steam dump bypass valves.

17-Apr-05 11:32 PRT level slowly rising indicating primary system leakage from either Pressurizer or PORV.

17-Apr-05 12:25 A. B, and C Steam Generator sampled - no primary to secondary leakage. Tail pipe temps on PORV 220 and steady. Dominion believes leakage from the PZR safety not PORV.

17-Apr-05 12:53 State of CT and NY EOCs staffed.

17-Apr-05 15:30 Cooling down to hot shutdown. Millstone Issues second press release.

17-Apr-05 16:40 Still no sample for D S/G.

17-Apr-05 22:00 Containment cooling restored.

17-Apr-05 08:30 As part of SI, chilled water to containment was Isolated. Due to the loss of containment cooling, containment pressure slowly Increased.

17-Apr-05 11:17 Dominion issues press release.

17-Apr-05 15:15 Millstone has stopped cooldown using D S/G because they have not been able to sample.

17-Apr-05 15:20 Secured C and D RCPs.

17-Apr-05 16:00 3 gpm leak from PORV into PRT.

17-Apr-05 17:07 CBS media inquiry. Transferred to Region 1.

17-Apr-05 17:24 Millstone feels it will be In Hot standby (Mode 4) by the LCO time limit The Initating event has been cleared for some time. They are considering securuing from the Alert.

17-Apr-05 17:26 Source of water going to PRT is still not known.

17-Apr-05 14:00 Commissioner Assistant brief 17-Apr-05 19:03 Reactor in Mode 4.

17-Apr-05 19:05 Licensee terminated the Alert.

17-Apr-05 20:37 Region I briefed Dyer, Collins, Merschoff, McGinty.

17-Apr-05 18:42 B PORV Isolated and down stream temperature decreased. B PORV was leaking 17-Apr-05 22:30 Sample D SIG no Indication of primary to secondary leak.

17-Apr-05 23:08 RHR running.

17-Apr-05 09:23 Millstone 3 notified NRC HOC of Alert.

17-Apr-05 23:45 NRC exited Monitoring Mode.