Event Notification Report for May 22, 2015
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
05/21/2015 - 05/22/2015
Power Reactor
Event Number: 51086
Facility: COLUMBIA GENERATING STATION
Region: 4 State: WA
Unit: [2] [] []
RX Type: [2] GE-5
NRC Notified By: MOT HEDGES
HQ OPS Officer: DANIEL MILLS
Region: 4 State: WA
Unit: [2] [] []
RX Type: [2] GE-5
NRC Notified By: MOT HEDGES
HQ OPS Officer: DANIEL MILLS
Notification Date: 05/22/2015
Notification Time: 10:43 [ET]
Event Date: 05/22/2015
Event Time: 00:14 [PDT]
Last Update Date: 05/22/2015
Notification Time: 10:43 [ET]
Event Date: 05/22/2015
Event Time: 00:14 [PDT]
Last Update Date: 05/22/2015
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
NICK TAYLOR (R4DO)
NICK TAYLOR (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | N | 0 | Refueling | 0 | Refueling |
EMERGENCY DIESEL GENERATOR START DUE TO ACTUATION OF UNDERVOLTAGE CIRCUITRY
"At 0014 PDT on 05/22/2015, Columbia experienced an unexpected momentary loss of SM-7, a Division 1 4.16 kV vital bus, resulting in a start of Emergency Diesel DG-1 . Additionally, under voltage circuitry prevented Standby Service Water pump 1A from starting to support DG-1 in response to the valid under voltage condition, and operators tripped the diesel at 0016 PDT. The SM-7 bus was reenergized by a 115 kV offsite source through backup transformer TR-B.
"The cause of this event was an inadvertent trip of under voltage circuitry while connecting test equipment in preparation for Diesel and Loss of Power logic testing. Division 1 was inoperable due to ongoing maintenance during the current refueling outage and was not being relied upon for decay heat removal or core circulation.
"Columbia is in Mode 5 with a coolant temperature of 96 degrees F, water level is at the normal refueling flooded level with fuel pool cooling gates removed. Division 2 is providing required electrical power and supporting components required for decay heat removal and inventory control. There was no impact to Shutdown Safety Assessment."
The NRC Resident Inspector has been notified.
"At 0014 PDT on 05/22/2015, Columbia experienced an unexpected momentary loss of SM-7, a Division 1 4.16 kV vital bus, resulting in a start of Emergency Diesel DG-1 . Additionally, under voltage circuitry prevented Standby Service Water pump 1A from starting to support DG-1 in response to the valid under voltage condition, and operators tripped the diesel at 0016 PDT. The SM-7 bus was reenergized by a 115 kV offsite source through backup transformer TR-B.
"The cause of this event was an inadvertent trip of under voltage circuitry while connecting test equipment in preparation for Diesel and Loss of Power logic testing. Division 1 was inoperable due to ongoing maintenance during the current refueling outage and was not being relied upon for decay heat removal or core circulation.
"Columbia is in Mode 5 with a coolant temperature of 96 degrees F, water level is at the normal refueling flooded level with fuel pool cooling gates removed. Division 2 is providing required electrical power and supporting components required for decay heat removal and inventory control. There was no impact to Shutdown Safety Assessment."
The NRC Resident Inspector has been notified.
Power Reactor
Event Number: 51087
Facility: PILGRIM
Region: 1 State: MA
Unit: [1] [] []
RX Type: [1] GE-3
NRC Notified By: MIKE MCDONNELL
HQ OPS Officer: STEVEN VITTO
Region: 1 State: MA
Unit: [1] [] []
RX Type: [1] GE-3
NRC Notified By: MIKE MCDONNELL
HQ OPS Officer: STEVEN VITTO
Notification Date: 05/22/2015
Notification Time: 13:36 [ET]
Event Date: 05/22/2015
Event Time: 10:02 [EDT]
Last Update Date: 05/24/2015
Notification Time: 13:36 [ET]
Event Date: 05/22/2015
Event Time: 10:02 [EDT]
Last Update Date: 05/24/2015
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL
Person (Organization):
JAMES DWYER (R1DO)
JAMES DWYER (R1DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 3 | Startup | 0 | Hot Shutdown |
MANUAL REACTOR SCRAM DUE TO LOSS OF CONDENSER VACUUM
"On Friday, May 22, 2015 at 1002 EDT, with the Reactor Mode Select Switch in the Start-Up position and the reactor at approximately 3 percent core thermal power, while returning to power from Refueling Outage Number 20, a manual reactor scram was inserted due to degrading main condenser vacuum. The cause of the degraded vacuum is currently under investigation.
"Following the reactor scram, all rods were verified to be fully inserted and no Emergency Operating Procedure entry conditions existed.
"All plant systems responded as designed.
"Currently reactor pressure is being maintained at 400 psig with the Mechanical Hydraulic Control System (turbine by-pass valves). Reactor water level is being maintained in normal bands with the Condensate and Feedwater System. Off-site power is being supplied to the station by the Startup Transformer (normal power supply for shutdown operations).
"This event had no impact on the health and/or safety of the public. The NRC Resident Inspector is on-site and has been notified.
"The licensee has notified the Massachusetts Emergency Management Agency."
The licensee will be issuing a press release.
* * * UPDATE FROM EVERETT PERKINS TO DONALD NORWOOD AT 1110 EDT ON 5/24/2015 * * *
The following was provided by the licensee as clarifying information to the first paragraph of the original event notification:
"As a conservative measure, the operating crew had previously started reducing power from 20 percent core thermal power when it was first noticed that main condenser vacuum was degrading. This was well before any low condenser vacuum alarms were received.
"During the shutdown, after already securing the main turbine, the operating crew established benchmark values for degrading condenser vacuum for a normal plant shutdown and for a manual reactor scram should vacuum continue to decline to preclude an automatic scram."
The licensee notified the NRC Resident Inspector.
Notified R1DO (Dwyer).
"On Friday, May 22, 2015 at 1002 EDT, with the Reactor Mode Select Switch in the Start-Up position and the reactor at approximately 3 percent core thermal power, while returning to power from Refueling Outage Number 20, a manual reactor scram was inserted due to degrading main condenser vacuum. The cause of the degraded vacuum is currently under investigation.
"Following the reactor scram, all rods were verified to be fully inserted and no Emergency Operating Procedure entry conditions existed.
"All plant systems responded as designed.
"Currently reactor pressure is being maintained at 400 psig with the Mechanical Hydraulic Control System (turbine by-pass valves). Reactor water level is being maintained in normal bands with the Condensate and Feedwater System. Off-site power is being supplied to the station by the Startup Transformer (normal power supply for shutdown operations).
"This event had no impact on the health and/or safety of the public. The NRC Resident Inspector is on-site and has been notified.
"The licensee has notified the Massachusetts Emergency Management Agency."
The licensee will be issuing a press release.
* * * UPDATE FROM EVERETT PERKINS TO DONALD NORWOOD AT 1110 EDT ON 5/24/2015 * * *
The following was provided by the licensee as clarifying information to the first paragraph of the original event notification:
"As a conservative measure, the operating crew had previously started reducing power from 20 percent core thermal power when it was first noticed that main condenser vacuum was degrading. This was well before any low condenser vacuum alarms were received.
"During the shutdown, after already securing the main turbine, the operating crew established benchmark values for degrading condenser vacuum for a normal plant shutdown and for a manual reactor scram should vacuum continue to decline to preclude an automatic scram."
The licensee notified the NRC Resident Inspector.
Notified R1DO (Dwyer).