| U.S. Nuclear Regulatory Commission
Operations Center Event Reports For
04/09/2012 - 04/10/2012 ** EVENT NUMBERS ** |
 | Power Reactor | Event Number: 47816 | Facility: SUSQUEHANNA
Region: 1 State: PA
Unit: [1] [2] [ ]
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: ALEX McLELLAN
HQ OPS Officer: MARK ABRAMOVITZ | Notification Date: 04/09/2012
Notification Time: 02:07 [ET]
Event Date: 04/09/2012
Event Time: 01:02 [EDT]
Last Update Date: 04/09/2012 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
| Person (Organization):
JOHN CARUSO (R1DO)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | N | N | 0 | Refueling | 0 | Refueling | | 2 | N | Y | 100 | Power Operation | 100 | Power Operation | Event Text BOTH CONTROL STRUCTURE CHILLERS DECLARED INOPERABLE WHILE SWITCHING POWER SUPPLIES
"On 4/9/2012, starting at 0102 EDT, the 'A' and 'C' Emergency Diesel Generators (EDG) were sequentially and briefly declared inoperable to switch their DC control power back to their normal supplies. Switching power to the normal supply is required by Unit 2 technical specification 3.8.4 following maintenance work on the U1 power supplies. Previously, at 18:35 EDT on 4/4/2012, the 'B' Control Structure Chiller was declared inoperable due to an unrelated problem. With the 'B' Control Structure Chiller inoperable coincident with the 'A' EDG or 'C' EDG inoperable, neither Control Structure Chiller would be available to perform its design function on a loss of offsite power. This is a condition that, at the time of discovery, could have prevented fulfillment of a Safety Function and is reportable under 50.72(b)(3)(v)(D) as an 8 hour notification.
"Switching the power supplies was a planned evolution. The duration of the loss of safety function was a total of eight minutes. As a mitigating action, operators were continuously available with communication to the control room. The associated diesel generator could have been returned to an operable condition promptly if required.
"Note that Technical Specifications allows four hours to correct the condition before further actions are required, i.e. declare the features ('A' Control Structure Chiller) supported by the inoperable diesel inoperable."
The licensee notified the NRC Resident Inspector. |
| Power Reactor | Event Number: 47817 | Facility: BRUNSWICK
Region: 2 State: NC
Unit: [1] [2] [ ]
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: LEE GOLDSTEIN
HQ OPS Officer: MARK ABRAMOVITZ | Notification Date: 04/09/2012
Notification Time: 09:15 [ET]
Event Date: 04/09/2012
Event Time: 05:29 [EDT]
Last Update Date: 04/09/2012 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
| Person (Organization):
GERALD MCCOY (R2DO)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | N | N | 0 | Refueling | 0 | Refueling | | 2 | N | Y | 100 | Power Operation | 100 | Power Operation | Event Text VALID EMERGENCY DIESEL GENERATOR ACTUATION
"On April 9, 2012, at 0529 hours, electrical power was lost to the 4160v emergency bus E1. Activities to support testing of emergency bus E1 were in progress when technicians connected a recorder across the terminals of an under-voltage relay on emergency bus E1 and caused the normal supply breakers for emergency bus E1 to open.
"The power loss to emergency bus E1 affected both Unit 1 and Unit 2. Emergency diesel generator #1 automatically started and re-energized the E1 emergency bus.
"Unit 1 was in Mode 5 and electrical systems were aligned to support testing of emergency bus E1. As a result, no other safety system isolations or actuations occurred. Per design, no Unit 2 safety system isolations or actuations occurred.
"The safety significance of this event is minimal. Safety systems functioned as designed when emergency bus E1 de-energized. There was no interruption of Unit 1 shutdown cooling as a result of this event. Normal power supply was restored to emergency bus E1 and emergency diesel generator #1 was shutdown at 0701 hours.
"Reporting requirements met by this notification: 10CFR50.72(b)(3)(iv)(A) with specified system in 10CFR50.72(b)(3) (iv)(B)(8). The NRC Resident Inspector has been notified." |
| Part 21 | Event Number: 47818 | Rep Org: ABB INC
Licensee: ABB INC
Region: 1
City: FLORENCE State: SC
County:
License #:
Agreement: Y
Docket:
NRC Notified By: DAVID BROWN
HQ OPS Officer: CHARLES TEAL | Notification Date: 04/09/2012
Notification Time: 17:06 [ET]
Event Date: 04/09/2012
Event Time: [EDT]
Last Update Date: 04/09/2012 | Emergency Class: NON EMERGENCY
10 CFR Section:
21.21(d)(3)(i) - DEFECTS AND NONCOMPLIANCE
| Person (Organization):
BLAKE WELLING (R1DO)
GERALD MCCOY (R2DO)
DAVID HILLS (R3DO)
VINCENT GADDY (R4DO)
PART 21 GROUP (EMAI)
| Event Text PART 21 REPORT - HK CIRCUIT BREAKER STUDS FAILED TO MEET SPECIFICATION
"This letter is submitted in accordance with 10 C.F.R. 21.21(d)(3)(ii) with respect to a failure to comply with the specifications associated with two studs P/N 163392A00 and 192247A00 used in medium voltage HK circuit breakers that may be subject to failure due to hydrogen embrittlement due to incorrect processing during plating. These studs were manufactured at the ABB Medium Voltage Service facility in Florence, SC from steel rod, heat treated in-house, and then sent to Surtronics for zinc plating with chromate treatment, including hydrogen embrittlement relief baking immediately following plating. A total of 51 pieces of P/N 163392A00 and 104 pieces of P/N 192247A00 were plated by Surtronics." | |