Event Notification Report for February 18, 2010
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
02/17/2010 - 02/18/2010
Power Reactor
Event Number: 45709
Facility: CALVERT CLIFFS
Region: 1 State: MD
Unit: [1] [2] []
RX Type: [1] CE,[2] CE
NRC Notified By: KENT MILLS
HQ OPS Officer: DONG HWA PARK
Region: 1 State: MD
Unit: [1] [2] []
RX Type: [1] CE,[2] CE
NRC Notified By: KENT MILLS
HQ OPS Officer: DONG HWA PARK
Notification Date: 02/18/2010
Notification Time: 11:47 [ET]
Event Date: 02/18/2010
Event Time: 08:24 [EST]
Last Update Date: 02/18/2010
Notification Time: 11:47 [ET]
Event Date: 02/18/2010
Event Time: 08:24 [EST]
Last Update Date: 02/18/2010
Emergency Class:
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):
TODD JACKSON (R1DO)
JOHN THORP (NRR)
JEFFERY GRANT (IRD)
TODD JACKSON (R1DO)
JOHN THORP (NRR)
JEFFERY GRANT (IRD)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | A/R | Y | 93 | Power Operation | 0 | Hot Standby |
| 2 | A/R | Y | 100 | Power Operation | 0 | Hot Standby |
DUAL UNIT AUTOMATIC REACTOR TRIPS DUE TO PARTIAL LOSS OF OFFSITE POWER
"Both U-1 and U-2 automatically tripped due to valid actuation of the Reactor Protection Systems (RPS). U-1 due to loss of 12B Reactor Coolant Pump (RCP) which resulted in a RCS Low Flow RPS Trip. Cause for loss of 12B RCP is currently not known but is suspected to be related to the electrical transient that occurred on U-2. U-2 tripped due to Loss of Load RPS Trip when the main turbine tripped due to an electrical malfunction and partial loss of offsite power. The electrical malfunction resulted in loss of power to all 4 Kv buses on U-2 with the exception of 21 4Kv bus (ZA train power) (Lost 22-26 4Kv buses) and the loss of 14 Kv bus (ZB train power) on U-1. All the buses lost are powered from the same in house service transformer, P-13000-2, which was lost due to the electrical transient. Cause of the electrical transient is being pursued but is unknown at this time. Loss of the 14 4Kv bus on U-1 and the 24 4Kv bus on U-2 resulted in an Engineered Safeguards Actuation System (ESFAS) valid actuations on both units due to Under Voltage (UV) conditions on those buses. The 1B [Diesel Generator] DG started automatically due to the 14 bus UV and is carrying that bus. The 2B DG received an automatic start signal due to the 24 bus UV but failed to start as expected. No other system actuations occurred. Both units are currently stable in Mode 3 at normal operating temperature (532 degrees) and pressure (2250 PSIA) with no other significant equipment malfunctions. Due to the loss of P-13000-2 [transformer], U-2 sustained a loss of normal heat removal due to loss of the main condenser cooling and the loss of secondary pumps. U-2 is removing heat with auxiliary feedwater pumps and [Steam Generator] SG atmospheric dump valves without issues. Current plans are to cool U-2 down to 445 degrees to maintain RCP seals cool until RCP's can be restarted. A decision on U-1 cool down has not yet been made."
There is no primary to secondary leakage. U-2 is currently in a 12 hour LCO due to the partial loss of offsite power and 2B DG failing to start.
The licensee has notified the NRC Resident Inspector.
"Both U-1 and U-2 automatically tripped due to valid actuation of the Reactor Protection Systems (RPS). U-1 due to loss of 12B Reactor Coolant Pump (RCP) which resulted in a RCS Low Flow RPS Trip. Cause for loss of 12B RCP is currently not known but is suspected to be related to the electrical transient that occurred on U-2. U-2 tripped due to Loss of Load RPS Trip when the main turbine tripped due to an electrical malfunction and partial loss of offsite power. The electrical malfunction resulted in loss of power to all 4 Kv buses on U-2 with the exception of 21 4Kv bus (ZA train power) (Lost 22-26 4Kv buses) and the loss of 14 Kv bus (ZB train power) on U-1. All the buses lost are powered from the same in house service transformer, P-13000-2, which was lost due to the electrical transient. Cause of the electrical transient is being pursued but is unknown at this time. Loss of the 14 4Kv bus on U-1 and the 24 4Kv bus on U-2 resulted in an Engineered Safeguards Actuation System (ESFAS) valid actuations on both units due to Under Voltage (UV) conditions on those buses. The 1B [Diesel Generator] DG started automatically due to the 14 bus UV and is carrying that bus. The 2B DG received an automatic start signal due to the 24 bus UV but failed to start as expected. No other system actuations occurred. Both units are currently stable in Mode 3 at normal operating temperature (532 degrees) and pressure (2250 PSIA) with no other significant equipment malfunctions. Due to the loss of P-13000-2 [transformer], U-2 sustained a loss of normal heat removal due to loss of the main condenser cooling and the loss of secondary pumps. U-2 is removing heat with auxiliary feedwater pumps and [Steam Generator] SG atmospheric dump valves without issues. Current plans are to cool U-2 down to 445 degrees to maintain RCP seals cool until RCP's can be restarted. A decision on U-1 cool down has not yet been made."
There is no primary to secondary leakage. U-2 is currently in a 12 hour LCO due to the partial loss of offsite power and 2B DG failing to start.
The licensee has notified the NRC Resident Inspector.
Power Reactor
Event Number: 45710
Facility: CATAWBA
Region: 2 State: SC
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: TOM POETZSCH
HQ OPS Officer: DONG HWA PARK
Region: 2 State: SC
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: TOM POETZSCH
HQ OPS Officer: DONG HWA PARK
Notification Date: 02/18/2010
Notification Time: 19:42 [ET]
Event Date: 02/18/2010
Event Time: 19:15 [EST]
Last Update Date: 02/18/2010
Notification Time: 19:42 [ET]
Event Date: 02/18/2010
Event Time: 19:15 [EST]
Last Update Date: 02/18/2010
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(A) - DEGRADED CONDITION
10 CFR Section:
50.72(b)(3)(ii)(A) - DEGRADED CONDITION
Person (Organization):
JONATHAN BARTLEY (R2DO)
MELANIE GALLOWAY (NRR)
JONATHAN BARTLEY (R2DO)
MELANIE GALLOWAY (NRR)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Hot Shutdown | 0 | Hot Shutdown |
RCS PRESSURE BOUNDARY LEAKAGE IDENTIFIED ON RTD WELD
"Catawba Nuclear Station is making an 8 hour notification due to a pressure boundary leak on the A loop of the Unit 1 Reactor Coolant System. The leak was found to be originating from 1A Reactor Coolant System hot leg [Resistance Temperature Detector] RTD penetration. Since the allowance for pressure boundary leakage is zero, this is being considered a degraded principal safety barrier. No safety signals were received and no actuations occurred as a result of this leak. The amount of the leak is small and is contained inside containment. No release to the environment occurred and there is no danger to the public. Repair will require the plant to enter Mode 5."
The pressure boundary leakage is 0.08 GPM. The licensee is in a 36 hour LCO 3.4.13(B)(2), and plans to be in Mode 5 this evening. The licensee has notified the NRC Resident Inspector.
"Catawba Nuclear Station is making an 8 hour notification due to a pressure boundary leak on the A loop of the Unit 1 Reactor Coolant System. The leak was found to be originating from 1A Reactor Coolant System hot leg [Resistance Temperature Detector] RTD penetration. Since the allowance for pressure boundary leakage is zero, this is being considered a degraded principal safety barrier. No safety signals were received and no actuations occurred as a result of this leak. The amount of the leak is small and is contained inside containment. No release to the environment occurred and there is no danger to the public. Repair will require the plant to enter Mode 5."
The pressure boundary leakage is 0.08 GPM. The licensee is in a 36 hour LCO 3.4.13(B)(2), and plans to be in Mode 5 this evening. The licensee has notified the NRC Resident Inspector.