Event Notification Report for December 29, 2007
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
12/28/2007 - 12/29/2007
EVENT NUMBERS
43874
Power Reactor
Event Number: 43874
Facility: SAINT LUCIE
Region: 2 State: FL
Unit: [] [2] []
RX Type: [1] CE,[2] CE
NRC Notified By: CALVIN WARD
HQ OPS Officer: MARK ABRAMOVITZ
Region: 2 State: FL
Unit: [] [2] []
RX Type: [1] CE,[2] CE
NRC Notified By: CALVIN WARD
HQ OPS Officer: MARK ABRAMOVITZ
Notification Date: 12/29/2007
Notification Time: 07:54 [ET]
Event Date: 12/29/2007
Event Time: 01:31 [EST]
Last Update Date: 12/29/2007
Notification Time: 07:54 [ET]
Event Date: 12/29/2007
Event Time: 01:31 [EST]
Last Update Date: 12/29/2007
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
SCOTT SHAEFFER (R2)
SCOTT SHAEFFER (R2)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | N | 0 | Hot Standby | 0 | Hot Standby |
MANUAL REACTOR TRIP WHEN FIVE CONTROL RODS UNEXPECTEDLY DROPPED 20 INCHES
"At 2320, on 12/28/07, a Reactor Startup was commenced. At 0025, on 12/29/07 Subgroup #15, of Regulating Group #3, was placed on the hold bus. Placing the Subgroup on the hold bus was a pre-planned action that was briefed prior to the reactor startup, in accordance with an approved interim engineering disposition. The interim engineering disposition was written and approved on 12/28/07 for concerns over CEA #1, of Subgroup #15, dropping into the core unexpectedly. Subgroup #15, of Regulating Group #3, contains five CEA's [CEA # 60, 62, 64, 66 and 1]. At 0047, all Regulating Group CEA's, with the exception of Regulating Group #5, were placed at the Upper Electrical Limit [136 inches withdrawn]. Regulating Group #5 was at 120 inches withdrawn in preparation for diluting to criticality. At 0107, the dilution to criticality was commenced. At 0131, all 5 CEA's in Subgroup #15 slipped into the core approximately 20 inches. A manual reactor trip was then ordered by the unit supervisor. 2-EOP-1, 'Standard Post Trip Actions' was then performed. The unit was borated to shutdown boron concentration. All Safety Functions were met satisfactorily and 2-EOP-1 was exited. The unit was in Mode 3 approaching Mode 2 at the time of the trip. The unit is currently stable in Mode 3, Hot Standby."
Reactor coolant pump heat is being removed using the atmospheric steam dumps.
The licensee notified the NRC Resident Inspector.
"At 2320, on 12/28/07, a Reactor Startup was commenced. At 0025, on 12/29/07 Subgroup #15, of Regulating Group #3, was placed on the hold bus. Placing the Subgroup on the hold bus was a pre-planned action that was briefed prior to the reactor startup, in accordance with an approved interim engineering disposition. The interim engineering disposition was written and approved on 12/28/07 for concerns over CEA #1, of Subgroup #15, dropping into the core unexpectedly. Subgroup #15, of Regulating Group #3, contains five CEA's [CEA # 60, 62, 64, 66 and 1]. At 0047, all Regulating Group CEA's, with the exception of Regulating Group #5, were placed at the Upper Electrical Limit [136 inches withdrawn]. Regulating Group #5 was at 120 inches withdrawn in preparation for diluting to criticality. At 0107, the dilution to criticality was commenced. At 0131, all 5 CEA's in Subgroup #15 slipped into the core approximately 20 inches. A manual reactor trip was then ordered by the unit supervisor. 2-EOP-1, 'Standard Post Trip Actions' was then performed. The unit was borated to shutdown boron concentration. All Safety Functions were met satisfactorily and 2-EOP-1 was exited. The unit was in Mode 3 approaching Mode 2 at the time of the trip. The unit is currently stable in Mode 3, Hot Standby."
Reactor coolant pump heat is being removed using the atmospheric steam dumps.
The licensee notified the NRC Resident Inspector.