Event Notification Report for April 10, 2005
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
04/09/2005 - 04/10/2005
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 41584
Facility: NINE MILE POINT
Region: 1 State: NY
Unit: [1] [] []
RX Type: [1] GE-2,[2] GE-5
NRC Notified By: QUENTIN HICKS
HQ OPS Officer: BILL HUFFMAN
Region: 1 State: NY
Unit: [1] [] []
RX Type: [1] GE-2,[2] GE-5
NRC Notified By: QUENTIN HICKS
HQ OPS Officer: BILL HUFFMAN
Notification Date: 04/10/2005
Notification Time: 11:46 [ET]
Event Date: 04/10/2005
Event Time: 05:00 [EST]
Last Update Date: 05/19/2005
Notification Time: 11:46 [ET]
Event Date: 04/10/2005
Event Time: 05:00 [EST]
Last Update Date: 05/19/2005
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):
JAMES NOGGLE (R1)
JAMES NOGGLE (R1)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | A | N | 0 | Refueling | 0 | Refueling |
SCRAM SIGNAL RESULTING FROM FAILURE OF A SUPPLY VALVE TO THE SCRAM AIR HEADER
"Nine Mile Point Unit 1 received a valid RPS SCRAM signal from high water level in the SCRAM Dump Volume (SDV). While restoring the Hydraulic Control Rod Unit (HCU) for control rod 02-35 to service, the internals to the plug valve for the Instrument Air Supply (116 Valve) to the SCRAM Inlet and Outlet valves failed. This failure caused an approximate 1/2" hole in the SCRAM Air Header, which resulted in the SCRAM Air Header pressure lowering rapidly due to the leak.
"Operators at the HCU recommended isolating the SCRAM Air Header. The Shift Manager was contacted by the job supervisor and received permission to isolate the SCRAM Air Header. SCRAM inlet and outlet valves opened, SDV vents and drains closed due to the loss of SCRAM Air Header pressure. Approximately 3 minutes after SCRAM Air Header depressurization, a full SCRAM signal occurred as expected due to the water level in the SDV. There was no fuel in the Reactor Vessel (RPV). No Control Rod motion occurred due to all Control Rods being inserted or isolated for maintenance.
"Immediate (8 Hour Non-Emergency) notification of this event being made as a result of the requirements of 10CRF50.72(b)3(iv)(A)."
The licensee stated that more information on the event can be found in Nine Mile Point Internal document DER - NM-2005-1565.
The license will be notifying the NRC Resident Inspector.
* * * RETRACTION PROVIDED BY LICENSEE (SHEEHAN) TO NRC (HELD) AT 1739 EDT ON 5/19/05 * * *
"The scram event that occurred on April 10, 2005 was not initiated from a 'valid' scram initiation signal (i.e., none of the instrumentation signals identified in Technical Specification Table 3.6.2a triggered the scram). To the contrary, a valve on a CRD hydraulic control unit (HCU) failed and Operations took action to isolate instrument air from the scram air header. This operator action had the identical effect that a scram signal would have had - the scram air header completely vented through the broken valve and caused the scram inlet and outlet valves on the HCUs to open and the scram discharge volume vents and drains to close. At the time, the reactor was defueled and all control rods were either already inserted or properly removed from service for maintenance, thus, the event did not result in any control rod movement (i.e., the system had been properly removed from service and the safety function had already been performed). Subsequent to the initiating event, as per the design of the CRD and RPS systems, the scram discharge volume filled and a full RPS scram signal was generated.
"Conclusion:
The scram event that occurred on April 10, 2005, resulted from an invalid scram initiation signal. At the time, the reactor was defueled, the CRD system had been properly removed from service and the safety function had been properly performed (no control rods moved). Thus, pursuant to the guidance in NUREG-1022, it is appropriate to conclude that the event is not reportable under 10CFR50.72(b)(2)(iv) or 10CFR50.73(a)(2)(iv). As such, the 8-hour ENS notification that was made at 11:46 on 4/10/05 (reference Event Number #41584) is being retracted."
The licensee notified the NRC Resident Inspector.
R1DO (Bellamy) was contacted.
"Nine Mile Point Unit 1 received a valid RPS SCRAM signal from high water level in the SCRAM Dump Volume (SDV). While restoring the Hydraulic Control Rod Unit (HCU) for control rod 02-35 to service, the internals to the plug valve for the Instrument Air Supply (116 Valve) to the SCRAM Inlet and Outlet valves failed. This failure caused an approximate 1/2" hole in the SCRAM Air Header, which resulted in the SCRAM Air Header pressure lowering rapidly due to the leak.
"Operators at the HCU recommended isolating the SCRAM Air Header. The Shift Manager was contacted by the job supervisor and received permission to isolate the SCRAM Air Header. SCRAM inlet and outlet valves opened, SDV vents and drains closed due to the loss of SCRAM Air Header pressure. Approximately 3 minutes after SCRAM Air Header depressurization, a full SCRAM signal occurred as expected due to the water level in the SDV. There was no fuel in the Reactor Vessel (RPV). No Control Rod motion occurred due to all Control Rods being inserted or isolated for maintenance.
"Immediate (8 Hour Non-Emergency) notification of this event being made as a result of the requirements of 10CRF50.72(b)3(iv)(A)."
The licensee stated that more information on the event can be found in Nine Mile Point Internal document DER - NM-2005-1565.
The license will be notifying the NRC Resident Inspector.
* * * RETRACTION PROVIDED BY LICENSEE (SHEEHAN) TO NRC (HELD) AT 1739 EDT ON 5/19/05 * * *
"The scram event that occurred on April 10, 2005 was not initiated from a 'valid' scram initiation signal (i.e., none of the instrumentation signals identified in Technical Specification Table 3.6.2a triggered the scram). To the contrary, a valve on a CRD hydraulic control unit (HCU) failed and Operations took action to isolate instrument air from the scram air header. This operator action had the identical effect that a scram signal would have had - the scram air header completely vented through the broken valve and caused the scram inlet and outlet valves on the HCUs to open and the scram discharge volume vents and drains to close. At the time, the reactor was defueled and all control rods were either already inserted or properly removed from service for maintenance, thus, the event did not result in any control rod movement (i.e., the system had been properly removed from service and the safety function had already been performed). Subsequent to the initiating event, as per the design of the CRD and RPS systems, the scram discharge volume filled and a full RPS scram signal was generated.
"Conclusion:
The scram event that occurred on April 10, 2005, resulted from an invalid scram initiation signal. At the time, the reactor was defueled, the CRD system had been properly removed from service and the safety function had been properly performed (no control rods moved). Thus, pursuant to the guidance in NUREG-1022, it is appropriate to conclude that the event is not reportable under 10CFR50.72(b)(2)(iv) or 10CFR50.73(a)(2)(iv). As such, the 8-hour ENS notification that was made at 11:46 on 4/10/05 (reference Event Number #41584) is being retracted."
The licensee notified the NRC Resident Inspector.
R1DO (Bellamy) was contacted.
Power Reactor
Event Number: 41585
Facility: SUSQUEHANNA
Region: 1 State: PA
Unit: [] [2] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: GORDON ROBINSON
HQ OPS Officer: WESLEY HELD
Region: 1 State: PA
Unit: [] [2] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: GORDON ROBINSON
HQ OPS Officer: WESLEY HELD
Notification Date: 04/10/2005
Notification Time: 12:08 [ET]
Event Date: 04/10/2005
Event Time: 11:50 [EDT]
Last Update Date: 04/12/2005
Notification Time: 12:08 [ET]
Event Date: 04/10/2005
Event Time: 11:50 [EDT]
Last Update Date: 04/12/2005
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(i) - PLANT S/D REQD BY TS
10 CFR Section:
50.72(b)(2)(i) - PLANT S/D REQD BY TS
Person (Organization):
JAMES NOGGLE (R1)
JAMES NOGGLE (R1)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | Y | 100 | Power Operation | 99 | Power Operation |
TECHNICAL SPECIFICATION REQUIRED SHUTDOWN DUE TO FAILED 125V DC BATTERY CHARGER
"At 0352 the 2C 125VDC battery charger failed. Fuses internal to the charger were found blown. Technical Specifications require restoration of the charger within 2 hrs or enter Mode 3 within the next 12 hrs and Mode 4 within the next 36 hrs. Investigation has not been able to restore the charger, and therefore the shutdown of the unit has commenced. Loads are currently being carried by the batteries, and personnel are monitoring battery voltage. Initial investigation has not identified any generic issues or any indication of tampering.
"This event is a Technical Specification required shutdown, and is reportable as a four hour ENS Notification under 10 CFR 50.72(b)(2)(i). Additionally, this is a voluntary notification due to an anticipated press release associated with the downpower towards unit shutdown."
There is evidence of degraded insulation on wires inside the affected battery charger. Battery loads are very small with an initial estimate of battery life at 80 hours. All safety systems are operable. There is no impact on Unit 1.
Unit 2 is expected to reach Mode 3 at 1720 on 4/10/05.
The NRC Resident Inspector has been notified. State (FEMA) will be notified.
* * * UPDATE PROVIDED BY LICENSEE (HUFFORD) TO NRC (HELD) AT 2030 ON 4/10/05 * * *
"At 17:28 the plant completed a normal reactor shutdown and entered Mode 3 in accordance with plant procedures to fulfill the requirements of Technical Specification 3.8.4. There were no ECCS initiations and lowest water level was approximately -4 inches."
The licensee reported that the 2C battery charger was back in service but remained in the LCO due to battery requirements. They are also completing engineering evaluations for extent of condition.
The NRC Resident Inspector was notified.
R1DO (Noggle) notified.
* * * UPDATE PROVIDED BY LICENSEE (KLINEFELTER) TO NRC (HELD) AT 1710 ON 4/12/05 * * *
"At 16:28 on April 12th, 2005 Susquehanna Unit 2 entered Mode 2 (Start-up) following the completion of repairs to the failed 125VDC battery charger and inspection to the remaining 3 Unit 2 125VDC battery chargers. A courtesy call was made [to] the Pennsylvania Emergency Management Agency. An informational press release will be made."
The NRC Resident Inspector was notified by the licensee.
R1DO (White) was notified.
"At 0352 the 2C 125VDC battery charger failed. Fuses internal to the charger were found blown. Technical Specifications require restoration of the charger within 2 hrs or enter Mode 3 within the next 12 hrs and Mode 4 within the next 36 hrs. Investigation has not been able to restore the charger, and therefore the shutdown of the unit has commenced. Loads are currently being carried by the batteries, and personnel are monitoring battery voltage. Initial investigation has not identified any generic issues or any indication of tampering.
"This event is a Technical Specification required shutdown, and is reportable as a four hour ENS Notification under 10 CFR 50.72(b)(2)(i). Additionally, this is a voluntary notification due to an anticipated press release associated with the downpower towards unit shutdown."
There is evidence of degraded insulation on wires inside the affected battery charger. Battery loads are very small with an initial estimate of battery life at 80 hours. All safety systems are operable. There is no impact on Unit 1.
Unit 2 is expected to reach Mode 3 at 1720 on 4/10/05.
The NRC Resident Inspector has been notified. State (FEMA) will be notified.
* * * UPDATE PROVIDED BY LICENSEE (HUFFORD) TO NRC (HELD) AT 2030 ON 4/10/05 * * *
"At 17:28 the plant completed a normal reactor shutdown and entered Mode 3 in accordance with plant procedures to fulfill the requirements of Technical Specification 3.8.4. There were no ECCS initiations and lowest water level was approximately -4 inches."
The licensee reported that the 2C battery charger was back in service but remained in the LCO due to battery requirements. They are also completing engineering evaluations for extent of condition.
The NRC Resident Inspector was notified.
R1DO (Noggle) notified.
* * * UPDATE PROVIDED BY LICENSEE (KLINEFELTER) TO NRC (HELD) AT 1710 ON 4/12/05 * * *
"At 16:28 on April 12th, 2005 Susquehanna Unit 2 entered Mode 2 (Start-up) following the completion of repairs to the failed 125VDC battery charger and inspection to the remaining 3 Unit 2 125VDC battery chargers. A courtesy call was made [to] the Pennsylvania Emergency Management Agency. An informational press release will be made."
The NRC Resident Inspector was notified by the licensee.
R1DO (White) was notified.