United States Nuclear Regulatory Commission - Protecting People and the Environment
Home > NRC Library > Document Collections > Reports Associated with Events > Event Notification Reports > 2011 > January 4

Event Notification Report for January 4, 2011

U.S. Nuclear Regulatory Commission
Operations Center

Event Reports For
01/03/2011 - 01/04/2011

** EVENT NUMBERS **


46518 46519

To top of page
Power Reactor Event Number: 46518
Facility: FORT CALHOUN
Region: 4 State: NE
Unit: [1] [ ] [ ]
RX Type: (1) CE
NRC Notified By: ERICK MATZKE
HQ OPS Officer: PETE SNYDER
Notification Date: 01/03/2011
Notification Time: 14:28 [ET]
Event Date: 01/03/2011
Event Time: 09:59 [CST]
Last Update Date: 01/03/2011
Emergency Class: NON EMERGENCY
10 CFR Section:
26.719 - FITNESS FOR DUTY
Person (Organization):
RICK DEESE (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

Event Text

SUPERVISOR FAILS RANDOM FITNESS FOR DUTY CHECK

A non-licensed employee supervisor had a confirmed positive for alcohol on a random fitness-for-duty test. The individual did not and does not have access to the protected area. Contact the Headquarters Operations Officer for additional details.

To top of page
Power Reactor Event Number: 46519
Facility: SUSQUEHANNA
Region: 1 State: PA
Unit: [1] [2] [ ]
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: GORDON ROBINSON
HQ OPS Officer: DONALD NORWOOD
Notification Date: 01/03/2011
Notification Time: 21:09 [ET]
Event Date: 01/03/2011
Event Time: 13:44 [EST]
Last Update Date: 01/03/2011
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
Person (Organization):
NEIL PERRY (R1DO)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N Y 98 Power Operation 98 Power Operation
2 N Y 94 Power Operation 94 Power Operation

Event Text

SINGLE POINT OF FAILURE VULNERABILITY DISCOVERED WHICH COULD POTENTIALLY AFFECT ACCIDENT RESPONSE

"On Monday, January 3, 2011, at 1344 EST, it was discovered by engineering that a single point of vulnerability exists at Susquehanna Steam Electric Station affecting both Unit 1 and Unit 2.

"A potential single HVAC control component has been discovered whose failure could result in a spurious Steam Leak Detection (SLD) isolation causing a loss of generation, loss of the normal heat sink (main condenser) and a loss of HPCI and RCIC. The SLD delta temperature (delta T) instrumentation is dependent on proper operation of the Unit 1 and Unit 2 RB [Reactor Building] HVAC heater temperature controller during cold weather operation. The Unit 1 and Unit 2 RB HVAC heaters are controlled by a single temperature controller which sends a signal to multiple step controllers. Failure of the temperature controller could cause the heaters to turn off. This would cause a significant decrease in RB HVAC supply temperature which results in a significant increase in measured SLD delta T during cold winter months. This could cause an isolation of the MSIVs, HPCI, RCIC and RWCU within a short period of time.

"This is reportable pursuant to 10CFR50.72(b)(3)(v) for a condition that at discovery could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident and 10CFR50.72(b)(3)(ii) for and event that resulted in the nuclear power plant being in an unanalyzed condition."

The licensee notified the NRC Resident Inspector.

Page Last Reviewed/Updated Thursday, March 29, 2012
Thursday, March 29, 2012