Event Notification Report for December 04, 2011
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
12/03/2011 - 12/04/2011
EVENT NUMBERS
47587
Power Reactor
Event Number: 47587
Facility: CLINTON
Region: 3 State: IL
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: DALE SHELTON
HQ OPS Officer: JOHN SHOEMAKER
Region: 3 State: IL
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: DALE SHELTON
HQ OPS Officer: JOHN SHOEMAKER
Notification Date: 01/12/2012
Notification Time: 11:36 [ET]
Event Date: 12/04/2011
Event Time: 06:09 [CST]
Last Update Date: 01/12/2012
Notification Time: 11:36 [ET]
Event Date: 12/04/2011
Event Time: 06:09 [CST]
Last Update Date: 01/12/2012
Emergency Class: NON EMERGENCY
10 CFR Section:
50.73(a)(1) - INVALID SPECIF SYSTEM ACTUATION
10 CFR Section:
50.73(a)(1) - INVALID SPECIF SYSTEM ACTUATION
Person (Organization):
STEVE ORTH (R3DO)
STEVE ORTH (R3DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Refueling | 0 | Refueling |
INVALID ACTUATION OF CONTAINMENT ISOLATION SIGNALS AND AN EMERGENCY SERVICE WATER PUMP
"The following information is provided as a sixty (60) day telephone notification to the NRC in accordance with 50.73 (a)(1) in lieu of the submittal of a written LER to report a condition that resulted in an invalid actuation of general containment isolation signals affecting containment isolation valves in more than one system and emergency service water systems that normally do not run and that serve as ultimate heat sinks. NUREG-1022, Revision 2, identifies the information that needs to be reported as discussed below.
"On December 4, 2011, Clinton Power Station was in Mode 5 (Refueling) conducting refueling outage activities, including the installation of a self test system power supply modification. During post-maintenance activities associated with the affected power supplies, an unexpected voltage reading was identified. While investigating the anomaly, one of the two nuclear system protection system essential logic power supplies was de-energized with the redundant power supply not yet restored. At 0609 [CST], the power supply was re-energized, resulting in an inadvertent actuation of the logic.
"Containment isolation valves on the following systems automatically closed: Instrument Air, Service Air, and Containment Floor Drain. Additionally, the Division 1 Shutdown Service Water (SX) Pump started. These actuations were not valid since the actuations were associated with low reactor water level conditions (Level 1 and Level 2) which were non-existent at the time of the event. The associated actuations were successful had the actuations been valid.
"This event is reportable in accordance with 10CFR50.73 (a)(2)(iv)(A) and has been entered into the Corrective Action Program."
The licensee notified the NRC Resident Inspector.
"The following information is provided as a sixty (60) day telephone notification to the NRC in accordance with 50.73 (a)(1) in lieu of the submittal of a written LER to report a condition that resulted in an invalid actuation of general containment isolation signals affecting containment isolation valves in more than one system and emergency service water systems that normally do not run and that serve as ultimate heat sinks. NUREG-1022, Revision 2, identifies the information that needs to be reported as discussed below.
"On December 4, 2011, Clinton Power Station was in Mode 5 (Refueling) conducting refueling outage activities, including the installation of a self test system power supply modification. During post-maintenance activities associated with the affected power supplies, an unexpected voltage reading was identified. While investigating the anomaly, one of the two nuclear system protection system essential logic power supplies was de-energized with the redundant power supply not yet restored. At 0609 [CST], the power supply was re-energized, resulting in an inadvertent actuation of the logic.
"Containment isolation valves on the following systems automatically closed: Instrument Air, Service Air, and Containment Floor Drain. Additionally, the Division 1 Shutdown Service Water (SX) Pump started. These actuations were not valid since the actuations were associated with low reactor water level conditions (Level 1 and Level 2) which were non-existent at the time of the event. The associated actuations were successful had the actuations been valid.
"This event is reportable in accordance with 10CFR50.73 (a)(2)(iv)(A) and has been entered into the Corrective Action Program."
The licensee notified the NRC Resident Inspector.