Event Notification Report for May 17, 2011
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
05/16/2011 - 05/17/2011
Power Reactor
Event Number: 46856
Facility: DIABLO CANYON
Region: 4 State: CA
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: KEN JOHNSTON
HQ OPS Officer: DONG HWA PARK
Region: 4 State: CA
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: KEN JOHNSTON
HQ OPS Officer: DONG HWA PARK
Notification Date: 05/17/2011
Notification Time: 15:42 [ET]
Event Date: 05/17/2011
Event Time: 09:54 [PDT]
Last Update Date: 05/17/2011
Notification Time: 15:42 [ET]
Event Date: 05/17/2011
Event Time: 09:54 [PDT]
Last Update Date: 05/17/2011
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):
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 |
EMERGENCY DIESEL GENERATORS START DUE TO MAINTENANCE ACTIVITIES
"At 0954 [PDT] on May 17, 2011, Unit 1 startup power was lost following actuation of the 230 kV line pilot wire differential relay 287X. Loss of power to the Unit 1 12 kV startup bus produced a startup undervoltage signal that caused all Unit 1 emergency diesel generators (EDGs) to start in a standby mode. The EDGs started as designed with no problems observed. No vital loads were affected as a result of the 12 kV bus loss and subsequent undervoltage. Actuation of differential relay 287X was due to maintenance activities on the safeguard relay board where differential relay 287X is installed.
"At 1056 on May 17, 2011, the Unit 112 kV startup power system was made available to supply power to the 4 kV vital buses. All Unit 1 EDGs were shutdown and returned to their normal at-power standby configuration, and differential relay 287X [was] reset.
"Unit 2 was unaffected by this event.
"The NRC Resident Inspector has been notified."
"At 0954 [PDT] on May 17, 2011, Unit 1 startup power was lost following actuation of the 230 kV line pilot wire differential relay 287X. Loss of power to the Unit 1 12 kV startup bus produced a startup undervoltage signal that caused all Unit 1 emergency diesel generators (EDGs) to start in a standby mode. The EDGs started as designed with no problems observed. No vital loads were affected as a result of the 12 kV bus loss and subsequent undervoltage. Actuation of differential relay 287X was due to maintenance activities on the safeguard relay board where differential relay 287X is installed.
"At 1056 on May 17, 2011, the Unit 112 kV startup power system was made available to supply power to the 4 kV vital buses. All Unit 1 EDGs were shutdown and returned to their normal at-power standby configuration, and differential relay 287X [was] reset.
"Unit 2 was unaffected by this event.
"The NRC Resident Inspector has been notified."
Power Reactor
Event Number: 46857
Facility: DRESDEN
Region: 3 State: IL
Unit: [] [2] [3]
RX Type: [1] GE-1,[2] GE-3,[3] GE-3
NRC Notified By: THOMAS DITCHFIELD
HQ OPS Officer: PETE SNYDER
Region: 3 State: IL
Unit: [] [2] [3]
RX Type: [1] GE-1,[2] GE-3,[3] GE-3
NRC Notified By: THOMAS DITCHFIELD
HQ OPS Officer: PETE SNYDER
Notification Date: 05/17/2011
Notification Time: 18:40 [ET]
Event Date: 05/17/2011
Event Time: 10:30 [CDT]
Last Update Date: 05/17/2011
Notification Time: 18:40 [ET]
Event Date: 05/17/2011
Event Time: 10:30 [CDT]
Last Update Date: 05/17/2011
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(B) - POT RHR INOP
10 CFR Section:
50.72(b)(3)(v)(B) - POT RHR INOP
Person (Organization):
JULIO LARA (R3DO)
JULIO LARA (R3DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | Y | 100 | Power Operation | 100 | Power Operation |
| 3 | N | Y | 100 | Power Operation | 100 | Power Operation |
TEMPORARY BLOCKAGE OF SUCTION SOURCE FOR CONTAINMENT COOLING SERVICE WATER
"On 5/17/2011, at 1404 CDT, Dresden Operations was notified by a Mechanical Maintenance Supervisor that both intake bay 13 stop logs were mistakenly installed during routine bay cleaning on 5/17/2011 at 1030. Installation of both bay 13 stop logs removes the suction source for the Containment Cooling Service Water (CCSW) system and renders the CCSW systems inoperable for both Dresden Units 2 and 3. Appropriate Technical Specification Required Actions were entered which direct restoration of at least one train of CCSW within 8 hours on each unit. Mechanical Maintenance was directed to remove the stop logs from Bay 13. At 1410 stop logs were removed and CCSW was declared operable for both Unit 2 and Unit 3. This event is reportable under 10 CFR 50.72 (b) (3) (v) an "Event or Condition That Could Have Prevented Fulfillment of a Safety Function."
The licensee notified the NRC Resident Inspector.
"On 5/17/2011, at 1404 CDT, Dresden Operations was notified by a Mechanical Maintenance Supervisor that both intake bay 13 stop logs were mistakenly installed during routine bay cleaning on 5/17/2011 at 1030. Installation of both bay 13 stop logs removes the suction source for the Containment Cooling Service Water (CCSW) system and renders the CCSW systems inoperable for both Dresden Units 2 and 3. Appropriate Technical Specification Required Actions were entered which direct restoration of at least one train of CCSW within 8 hours on each unit. Mechanical Maintenance was directed to remove the stop logs from Bay 13. At 1410 stop logs were removed and CCSW was declared operable for both Unit 2 and Unit 3. This event is reportable under 10 CFR 50.72 (b) (3) (v) an "Event or Condition That Could Have Prevented Fulfillment of a Safety Function."
The licensee notified the NRC Resident Inspector.