ML051450533

Event Notification Report for April 26, 2005

ML051450533
Person / Time
Site:	Millstone
Issue date:	04/26/2005
From:	NRC Region 1
To:
References
FOIA/PA-2005-0208
Download: ML051450533 (2)

Text

.',veni Notification Report for April 26, 2005 Page1 of 2 U.S. Nuclear Regulatory Commission Operation Center Power Reactor Event Number: 41607 Facility: MILLSTONE Notification Date: 04/17/2005 Region: 1 State: CT Notification Time: 09:23 [EST]

Unit: [3] Event Date: 04/17/2005 RX Type: [1] GE-3,[2] CE,[3] W-4-LP Event Time: 08:42 [EDT]

NRC Notified By: MICHAEL GOBELI Last Update Date: 04/17/2005 HO OPS Officer: JOHN KNOKE Emergency Class:ALERT Person (Organization):

10 CFR Section: SAM COLLINS (RA) 50.72(a) (1) (i) - EMERGENCY DECLARED TIM MCGINTY (IRD) 50.72(b)(2)(iv)(A) - ECCS INJECTION JIM DYER (ET) 50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL R1 BLAST DIAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION E. BRENNER (PAO)

THOMAS (NRC) l SCAM l l Initial l l Current Unit Code IRXCRIT PWR initial RX Mode I PWR Current RX Mode 3 AIAR -1~ 100 Power Operation 0 Hot Standby Event Text 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) actuations 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.

03Z

Evens Notification Report for April 26, 2005 Page 2 of 2 U.S. Nuclear Regulatory Commission Operation Center Notified R1 DO (J.White) and IRD Manager (T. McGinty)

• • • UPDATE FROM D. DODSON TOW. GOTT AT 1915 ON 04/17/05 *

'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.