ML072990326

NRC Event Notification Report for September 13, 2007 Fitzpatrick Reactor Scram Following Intake Structure Traveling Screen Fouling

ML072990326
Person / Time
Site:	FitzPatrick
Issue date:	09/12/2007
From:	Entergy Nuclear Operations
To:	James Trapp NRC Region 1
References
43635
Download: ML072990326 (1)

Text

NRC: Event Notification Report for September 13, 2007 Page 4 of 5 Power Reactor Event Number: 43635 Facility: FITZPATRICK Notification Date: 09/12/2007 Region: 1 State: NY Notification Time: 09:58 [ET]

Unit: [1] [ ] [ ] Event Date: 09/12/2007 RX Type: [1] GE-4 Event Time: 06:35 [EDT]

NRC Notified By: GENE DORMAN Last Update Date: 09/12/2007 HQ OPS Officer: PETE SNYDER Emergency Class: NON EMERGENCY Person (Organization):

10 CFR Section: JAMES TRAPP (R1) 50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION SCRAM Current Unit Code RX CRIT Initial PWR Initial RX Mode PWR Current RX 1 M/R Y 100 Power Operation 0 Hot Shutd Event Text REACTOR SCRAM FOLLOWING INTAKE STRUCTURE TRAVELING SCREEN FOULING "As a result of high winds and a severe storm front moving through the area a Nuclear Plant Operator (NPO) intake canal water murky, wind speed was noted to be 40 MPH. The Traveling Screens were placed in the con mode of operation and increased monitoring was put in effect. At 0520 the NPO noted that 'a lot of weeds an coming in through the intake' and that a full trash basket had been changed out. At approximately 0630 the reported that the traveling screens were not moving and intake level was lowering due to the influx of debris Nuclear Operator (SNO) entered the appropriate Abnormal Operating Procedure (AOP) for lowering intake lev commenced rapid power reduction. At 0635 with intake level at 240 feet the SNO inserted a manual scram a the appropriate AOP and Emergency Operating Procedure (EOP).

"Reactor Vessel level decreased to less than 177 inches above the top of active fuel resulting in a Primary Co Isolation System (PCIS) Group 2 isolation signal. The PCIS Group 2 isolation resulted in a valid signal to close valves in the Drywell Floor Drain System, the Drywell Equipment Drain System, the Residual Heat Removal (

System, the Traversing In-Core Probe (TIP) System, the Containment Atmosphere Dilution (CAD) System, an Reactor Water Clean-Up (RWCU) System. However, as a result of the power reduction the operators were ab maintain reactor vessel level above the actuation setpoint for the High Pressure Coolant Injection (HPCI) Sys the Reactor Core Isolation Cooling (RCIC) Systems and these systems were not required to operate.

"At 0640 the Scram was reset, at 0710 the Group 2 PCIS Isolation was verified, and at 0729 the Group 2 PCI was reset.

"The cause of the traveling screens stopping has been determined to be due to shear pins on the traveling w shearing due to excessive debris loading.

"All equipment responded as expected during the downpower and subsequent manual Scram. All rods are in plant is stable in MODE 3, Hot Shutdown." Decay heat is being removed by dumping steam to the condenser turbine bypass valves. The safety buses are being powered by offsite power. The 'B' train Residual Heat Rem was out of service at the time of the event for planned maintenance.

The licensee notified the NRC Resident Inspector.

• *

• UPDATE FROM G. DORMAN TO J. KNOKE AT 1205 EDT ON 09/12/07 * * *

"At 1034 with the plant shutdown and a cooldown in progress reactor vessel (RV) level lowered to less than 1 above TAF [Top of Active Fuel]. This resulted in a valid Reactor Protection System (RPS) Scram signal and a 2 Isolation Signal. AP systems responded as expected. Reactor vessel level remained above the actuation set HPCI and RCIC and they were not required to operate. RV level was restored and the Scram was reset.

"At the time of the initial event and at this update the plant is in LCO action statement 3.5.1.A for the 'B' RHR being out of service. The system is being restored at this time.

The licensee notified the NRC Resident Inspector. The licensee also notified the state and is providing a press the media. Notified R1DO (Trapp).

http://www.nrc.gov/reading-rm/doc-collections/event-status/event/2007/20070913en.html 10/25/2007