| U.S. Nuclear Regulatory Commission
Operations Center Event Reports For
02/28/2011 - 03/01/2011 ** EVENT NUMBERS ** |
 | 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: 02/28/2011 | 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.
* * * UPDATE FROM TODD CREASY TO JOE O'HARA AT 1310 ON 2/28/11 * * *
"On January 3, 2011, SSES reported the discovery of a single point vulnerability that affected both Unit 1 and Unit 2 (EN # 46519). The vulnerability involved failure of a temperature controller that had the potential to result in a 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 condition was reported pursuant to 10CFR50.72(b)(3)(v) as a condition that at discovery could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident and pursuant to 10CFR50.72(b)(3)(ii) as an event that resulted in the nuclear power plant being in an unanalyzed condition.
"SSES has further evaluated the condition and determined that the condition did not meet reporting criterion 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.
"The level of judgment in reporting under this criterion Is a reasonable expectation of preventing fulfillment of a safety function. Alternately stated, the condition is reportable if there was reasonable doubt that the safety function would have been fulfilled if the system had been called upon to perform it. Technical evaluation of the condition concluded the following: there is reasonable assurance (high degree of confidence) that the HPCI, RCIC, Main Steam Isolation and RWCU systems will remain operable. The identified condition does not adversely affect the operability of the affected systems. The identified condition increases the probability that a failure of the Reactor Building HVAC temperature controller TC-17589 or TC-27589 could cause the MSIV's, HPCI and RCIC to isolate during cold weather operation. However, this increase in probability is very small and is not sufficient to erode the confidence in the reasonable expectation of operability. For a system isolation to occur, the heater controller had to fail and concurrently the outside air temperature had to be below approximately 10?F. The Reactor Building HVAC temperature controllers are highly reliable and the outside air temperatures required for this event occur infrequently (there have only been 11 instances of temperatures at Susquehanna dropping below 10 deg F in the past two years). Since both infrequent conditions have to occur concurrently, it is unlikely that this postulated failure would occur.
"As a result, reporting pursuant to 10CFR50.72(b)(3)(v) is retracted; however, the condition remains reportable pursuant to 10CFR50.72(b)b)(3)(ii) as an event that resulted in the nuclear power plant being in an unanalyzed condition."
The NRC Resident Inspector has been notified.
Notified R1DO (T.Dimitriadis) |
| Power Reactor | Event Number: 46646 | Facility: POINT BEACH
Region: 3 State: WI
Unit: [ ] [2] [ ]
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: RUSS PARKER
HQ OPS Officer: VINCE KLCO | Notification Date: 02/28/2011
Notification Time: 03:45 [ET]
Event Date: 02/27/2011
Event Time: 21:59 [CST]
Last Update Date: 02/28/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
| Person (Organization):
DAVID HILLS (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 | Event Text DEGRADED ACCIDENT MITIGATION DUE TO SAFETY INJECTION OUT OF SERVICE
"At 2159 CST on 2/27/2011, during the testing of the 'A' Train Safety Injection System, an Auxiliary Operator in the field identified that the oiler for 2P-15B, 'B' Train Safety Injection Pump, had rotated and the oil had drained out of the oiler. The Auxiliary Operator immediately reported this condition to control room personnel. The 'B' train safety injection pump was declared inoperable and LCO 3.0.3 was entered based upon the condition of both trains of safety injection being out of service. The Unit 2 'A' Train Safety Injection System was being tested in accordance with inservice testing procedure IT-535C, Leakage Reduction and Preventive Maintenance Program Train 'A' HHSI and RHR Piggyback Test Mode 1,5,6 (Refueling) Unit 2, which placed the Unit 2 ECCS in TSAC [Technical Specification Action Condition] 3.5.2.A, One ECCS Train Inoperable.
"Unit 2 exited LCO 3.0.3 at 2211 CST, upon completion of the 'A' train inservice test. The 2P-151B safety injection pump remains inoperable in accordance with TSAC 3.5.2.A, One ECCS Train Inoperable for troubleshooting and repair. This condition is reported in accordance with 10 CFR 50.72(b)(3)(v)(D) Accident Mitigation."
There was no impact on Unit 1 and the licensee notified the NRC Resident Inspector. |
| Part 21 | Event Number: 46647 | Rep Org: TYCO ELECTRONICS
Licensee: TYCO ELECTRONICS
Region: 1
City: FAIRWIEW State: NC
County:
License #:
Agreement: Y
Docket:
NRC Notified By: SCOTT DAUBERT
HQ OPS Officer: VINCE KLCO | Notification Date: 02/28/2011
Notification Time: 10:00 [ET]
Event Date: 02/28/2011
Event Time: [EST]
Last Update Date: 02/28/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
21.21 - UNSPECIFIED PARAGRAPH
| Person (Organization):
MARK FRANKE (R2DO)
DAVID HILLS (R3DO)
PART 21 GRP ()
| Event Text PART 21 REPORT - SPECIFIED RELAYS WITH DEGRADED COILS
During the dedication process of nuclear E7000 relays, Tyco Electronics experienced an issue with a component. This component, a coil internal to the relay, failed to operate during quality assurance testing.
Tyco purged this lot of coils from their inventory and also from all "work in process." Tyco was able to account for all the coils in this lot of E7000 relays with serial numbers beginning with 1046. Tyco records indicate that some relays shipped to the Exelon/Quad Cities facility were made using this specific coil lot. Tyco sold this safety-related item for specified and unspecified applications. | |