Event Notification Report for October 11, 2010
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
10/10/2010 - 10/11/2010
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 46327
Facility: MONTICELLO
Region: 3 State: MN
Unit: [1] [] []
RX Type: [1] GE-3
NRC Notified By: MARK PIKUS
HQ OPS Officer: CHARLES TEAL
Region: 3 State: MN
Unit: [1] [] []
RX Type: [1] GE-3
NRC Notified By: MARK PIKUS
HQ OPS Officer: CHARLES TEAL
Notification Date: 10/11/2010
Notification Time: 22:05 [ET]
Event Date: 10/11/2010
Event Time: 13:05 [CDT]
Last Update Date: 10/29/2010
Notification Time: 22:05 [ET]
Event Date: 10/11/2010
Event Time: 13:05 [CDT]
Last Update Date: 10/29/2010
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
Person (Organization):
DAVE PASSEHL (R3DO)
DAVE PASSEHL (R3DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 95 | Power Operation | 95 | Power Operation |
TECHNICAL SPECIFICATION DOES NOT ACCOUNT FOR POWER UPRATE
"On October 11, 2010 at 1305 CDT it was identified that the analysis of record for the Technical Specification 3.3.5.1, Table 3.3.5.1-1 function 1e and 2e, Reactor Steam Dome Pressure Permissive-Bypass timer (Pump Permissive) did not reflect current plant conditions. Specifically, the analysis was not updated to account for any increase in plant licensed power and a change to the RWCU (Reactor Water Cleanup System) isolation for enhanced ability to isolate RWCU on a line break on critical crack. The allowable value for these function is greater than or equal to 18 minutes and less than or equal to 22 minutes.
"All equipment associated with emergency core cooling function are unaffected. Discussion with General Electric indicates that a margin exists to accommodate the higher power level. Additionally, the changes to the RWCU isolation logic added leak detection instruments that will isolate RWCU earlier for the majority of pipe leaks. This discovery is being reported as an unanalyzed condition solely due to the lack of a formal analysis of current plant conditions."
The NRC Resident Inspector has been notified.
* * * RETRACTION FROM MARTIN RAJKOWSKI TO JOHN KNOKE AT 1451 ON 10/29/10 * * *
"Under NUREG-0737, Item II.K.3.18 is a regulatory requirement to implement a modification to extend the ADS [Automatic Depressurization System] to a unique event sequence that involves multiple failures including HPCI [High Pressure Coolant Injection] plus no operator action after 10 minutes. According to Item II.K.3.18, the bypass timer logic complements, but does not replace, the existing ADS actuation logic. This requirement is not associated with any design basis accident mitigation sequence at MNGP [Monticello Nuclear Generating Plant].
"The plant has performed an evaluation that addresses the changes in plant thermal power and RWCU (Reactor Water Cleanup System) enhanced isolation capabilities to the analysis of record. This evaluation concluded that Peak Clad Temperature (PCT) will remain under the 2200 ?F acceptance limit with the current Technical Specification allowable value, current plant configuration and current licensed thermal power.
GEH [General Electric] did an independent evaluation that concluded that based on use of limiting scenarios analyzed for MNGP, this condition is only a lack of formal analysis of current plant conditions and that no Substantial Safety Hazard exists. It is judged that the maximum Reactor Steam Dome Pressure Permissive-Bypass timer (Pump Permissive) setting of 22 minutes will not result in a predicted PCT higher than 2200?F with consideration of the RWCU pipe break isolation instrumentation modification.
"Since the timers with their current setpoint will protect the fuel cladding, this event does not significantly degrade safety. Therefore, the event notification made on October 11, 2010 is being retracted."
The licensee has notified the NRC Resident Inspector. Notified R3DO (Skokowski)
"On October 11, 2010 at 1305 CDT it was identified that the analysis of record for the Technical Specification 3.3.5.1, Table 3.3.5.1-1 function 1e and 2e, Reactor Steam Dome Pressure Permissive-Bypass timer (Pump Permissive) did not reflect current plant conditions. Specifically, the analysis was not updated to account for any increase in plant licensed power and a change to the RWCU (Reactor Water Cleanup System) isolation for enhanced ability to isolate RWCU on a line break on critical crack. The allowable value for these function is greater than or equal to 18 minutes and less than or equal to 22 minutes.
"All equipment associated with emergency core cooling function are unaffected. Discussion with General Electric indicates that a margin exists to accommodate the higher power level. Additionally, the changes to the RWCU isolation logic added leak detection instruments that will isolate RWCU earlier for the majority of pipe leaks. This discovery is being reported as an unanalyzed condition solely due to the lack of a formal analysis of current plant conditions."
The NRC Resident Inspector has been notified.
* * * RETRACTION FROM MARTIN RAJKOWSKI TO JOHN KNOKE AT 1451 ON 10/29/10 * * *
"Under NUREG-0737, Item II.K.3.18 is a regulatory requirement to implement a modification to extend the ADS [Automatic Depressurization System] to a unique event sequence that involves multiple failures including HPCI [High Pressure Coolant Injection] plus no operator action after 10 minutes. According to Item II.K.3.18, the bypass timer logic complements, but does not replace, the existing ADS actuation logic. This requirement is not associated with any design basis accident mitigation sequence at MNGP [Monticello Nuclear Generating Plant].
"The plant has performed an evaluation that addresses the changes in plant thermal power and RWCU (Reactor Water Cleanup System) enhanced isolation capabilities to the analysis of record. This evaluation concluded that Peak Clad Temperature (PCT) will remain under the 2200 ?F acceptance limit with the current Technical Specification allowable value, current plant configuration and current licensed thermal power.
GEH [General Electric] did an independent evaluation that concluded that based on use of limiting scenarios analyzed for MNGP, this condition is only a lack of formal analysis of current plant conditions and that no Substantial Safety Hazard exists. It is judged that the maximum Reactor Steam Dome Pressure Permissive-Bypass timer (Pump Permissive) setting of 22 minutes will not result in a predicted PCT higher than 2200?F with consideration of the RWCU pipe break isolation instrumentation modification.
"Since the timers with their current setpoint will protect the fuel cladding, this event does not significantly degrade safety. Therefore, the event notification made on October 11, 2010 is being retracted."
The licensee has notified the NRC Resident Inspector. Notified R3DO (Skokowski)
Power Reactor
Event Number: 46324
Facility: FT CALHOUN
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] CE
NRC Notified By: AARON CHLADIL
HQ OPS Officer: CHARLES TEAL
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] CE
NRC Notified By: AARON CHLADIL
HQ OPS Officer: CHARLES TEAL
Notification Date: 10/11/2010
Notification Time: 12:10 [ET]
Event Date: 10/11/2010
Event Time: 11:10 [CDT]
Last Update Date: 10/14/2010
Notification Time: 12:10 [ET]
Event Date: 10/11/2010
Event Time: 11:10 [CDT]
Last Update Date: 10/14/2010
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
MICHAEL SHANNON (R4DO)
MICHAEL SHANNON (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
TECHNICAL SUPPORT CENTER OOS FOR MAINTENANCE
"This is an eight-hour report as required per 10 CFR 50.72(b)(3)(xiii) due to maintenance which will result in the Fort Calhoun Station Technical Support Center (TSC) being degraded. On Monday, October 11th scheduled maintenance will commence on the TSC Air Handling unit that will render the unit non-functional. This maintenance is scheduled to be completed on Thursday, October 14th. Station procedures contain compensatory measures to ensure appropriate habitability monitoring and, if necessary, relocation of TSC personnel should the need exist to activate the emergency response organization."
The NRC Resident Inspector has been notified.
* * * UPDATE FROM BARTON SCHAWE TO HOWIE CROUCH AT 1643 EDT ON 10/14/10 * * *
At 1519 CDT, the TSC Air Handling Unit was returned to service and is functional. The licensee will notify the NRC Resident Inspector.
Notified R4DO (Haire).
"This is an eight-hour report as required per 10 CFR 50.72(b)(3)(xiii) due to maintenance which will result in the Fort Calhoun Station Technical Support Center (TSC) being degraded. On Monday, October 11th scheduled maintenance will commence on the TSC Air Handling unit that will render the unit non-functional. This maintenance is scheduled to be completed on Thursday, October 14th. Station procedures contain compensatory measures to ensure appropriate habitability monitoring and, if necessary, relocation of TSC personnel should the need exist to activate the emergency response organization."
The NRC Resident Inspector has been notified.
* * * UPDATE FROM BARTON SCHAWE TO HOWIE CROUCH AT 1643 EDT ON 10/14/10 * * *
At 1519 CDT, the TSC Air Handling Unit was returned to service and is functional. The licensee will notify the NRC Resident Inspector.
Notified R4DO (Haire).
Power Reactor
Event Number: 46325
Facility: DRESDEN
Region: 3 State: IL
Unit: [] [] [3]
RX Type: [1] GE-1,[2] GE-3,[3] GE-3
NRC Notified By: JEFF SIMPSON
HQ OPS Officer: BILL HUFFMAN
Region: 3 State: IL
Unit: [] [] [3]
RX Type: [1] GE-1,[2] GE-3,[3] GE-3
NRC Notified By: JEFF SIMPSON
HQ OPS Officer: BILL HUFFMAN
Notification Date: 10/11/2010
Notification Time: 13:38 [ET]
Event Date: 10/11/2010
Event Time: 10:04 [CDT]
Last Update Date: 10/20/2010
Notification Time: 13:38 [ET]
Event Date: 10/11/2010
Event Time: 10:04 [CDT]
Last Update Date: 10/20/2010
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
DAVE PASSEHL (R3DO)
DAVE PASSEHL (R3DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 3 | A/R | Y | 94 | Power Operation | 0 | Hot Shutdown |
AUTOMATIC REACTOR SCRAM DURING TRANSFER OF REACTOR PROTECTION SYSTEM BUS
"On October 11, 2010 in preparation for maintenance, the 'A' Reactor Protection System Bus was being transferred from the normal to the reserve power supply. As a part of the transfer, a half scram is expected. During the transfer a [full] reactor scram occurred. All rods inserted to their full-in positions.
"Following the reactor scram, all systems operated as expected. Reactor vessel inventory is being maintained by the Condensate / Feedwater system.
"Following the scram, the Unit 2/3 Emergency Diesel Generator auto started due to the transfer of the Auxiliary Power system.
"Currently the cause of the full Reactor Protection System [scram] is unknown. Troubleshooting is in progress to determine the malfunction.
"This condition is being reported pursuant to 10 CFR 50.72(b)(2)(iv)(B), Any event or condition that results in actuation of the reactor protection system (RPS) when the reactor is critical."
The auto-start of the EDG was expected as a result of the 'A' RPS bus transfer and has been secured and placed back in standby. Decay heat is being discharged to the condenser. The Unit is in a normal shutdown electrical line-up. The scram had no impact on Unit 2. The licensee characterized the scram as uncomplicated.
The NRC Resident Inspector has been notified.
* * * UPDATE FROM RILEY RUFFIN TO ERIC SIMPSON 1415 EDT ON 10/20/10 * * *
The second to last paragraph of the original report has been updated to read as follows:
"The auto-start of the EDG was anticipated as a result of the Auxiliary Power System transfer and has been secured and placed back in standby."
The R3DO (Orth) has been notified.
"On October 11, 2010 in preparation for maintenance, the 'A' Reactor Protection System Bus was being transferred from the normal to the reserve power supply. As a part of the transfer, a half scram is expected. During the transfer a [full] reactor scram occurred. All rods inserted to their full-in positions.
"Following the reactor scram, all systems operated as expected. Reactor vessel inventory is being maintained by the Condensate / Feedwater system.
"Following the scram, the Unit 2/3 Emergency Diesel Generator auto started due to the transfer of the Auxiliary Power system.
"Currently the cause of the full Reactor Protection System [scram] is unknown. Troubleshooting is in progress to determine the malfunction.
"This condition is being reported pursuant to 10 CFR 50.72(b)(2)(iv)(B), Any event or condition that results in actuation of the reactor protection system (RPS) when the reactor is critical."
The auto-start of the EDG was expected as a result of the 'A' RPS bus transfer and has been secured and placed back in standby. Decay heat is being discharged to the condenser. The Unit is in a normal shutdown electrical line-up. The scram had no impact on Unit 2. The licensee characterized the scram as uncomplicated.
The NRC Resident Inspector has been notified.
* * * UPDATE FROM RILEY RUFFIN TO ERIC SIMPSON 1415 EDT ON 10/20/10 * * *
The second to last paragraph of the original report has been updated to read as follows:
"The auto-start of the EDG was anticipated as a result of the Auxiliary Power System transfer and has been secured and placed back in standby."
The R3DO (Orth) has been notified.