Event Notification Report for November 06, 2020
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
11/05/2020 - 11/06/2020
Power Reactor
Event Number: 54986
Facility: Grand Gulf
Region: 4 State: MS
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: Jason Overcash
HQ OPS Officer: Thomas Kendzia
Region: 4 State: MS
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: Jason Overcash
HQ OPS Officer: Thomas Kendzia
Notification Date: 11/06/2020
Notification Time: 05:00 [ET]
Event Date: 11/06/2020
Event Time: 02:39 [CST]
Last Update Date: 11/06/2020
Notification Time: 05:00 [ET]
Event Date: 11/06/2020
Event Time: 02:39 [CST]
Last Update Date: 11/06/2020
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):
DAVID PROULX (R4DO)
DAVID PROULX (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | A/R | Y | 84 | Power Operation | 0 | Hot Shutdown |
AUTOMATIC REACTOR SCRAM DUE TO TURBINE/GENERATOR TRIP
"On November 6, 2020, at 0239 CST, Grand Gulf Nuclear Station (GGNS) experienced an Automatic Reactor Scram from 84 percent Reactor Power after a Main Turbine and Generator Trip.
"All control rods fully inserted and there were no complications. All systems responded as designed.
"Reactor pressure is being maintained with Main Turbine Bypass Valves. Reactor water level is being maintained in normal band with the condensate system.
"No radiological releases have occurred due to this event from the unit.
"The NRC Resident has been notified."
"On November 6, 2020, at 0239 CST, Grand Gulf Nuclear Station (GGNS) experienced an Automatic Reactor Scram from 84 percent Reactor Power after a Main Turbine and Generator Trip.
"All control rods fully inserted and there were no complications. All systems responded as designed.
"Reactor pressure is being maintained with Main Turbine Bypass Valves. Reactor water level is being maintained in normal band with the condensate system.
"No radiological releases have occurred due to this event from the unit.
"The NRC Resident has been notified."
Power Reactor
Event Number: 55026
Facility: Millstone
Region: 1 State: CT
Unit: [] [] [3]
RX Type: [1] GE-3,[2] CE,[3] W-4-LP
NRC Notified By: Dan Beachy
HQ OPS Officer: Solomon Sahle
Region: 1 State: CT
Unit: [] [] [3]
RX Type: [1] GE-3,[2] CE,[3] W-4-LP
NRC Notified By: Dan Beachy
HQ OPS Officer: Solomon Sahle
Notification Date: 12/10/2020
Notification Time: 10:58 [ET]
Event Date: 11/06/2020
Event Time: 19:08 [EST]
Last Update Date: 12/10/2020
Notification Time: 10:58 [ET]
Event Date: 11/06/2020
Event Time: 19:08 [EST]
Last Update Date: 12/10/2020
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):
FRED BOWER (R1DO)
FRED BOWER (R1DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 3 | N | N | 0 | Hot Standby | 0 |
60-DAY OPTIONAL TELEPHONIC NOTIFICATION OF AN INVALID SPECIFIED SYSTEM ACTUATION
"This 60-day telephone notification is being submitted in accordance with paragraphs 10 CFR 50.73(a)(1) and 50.73(a)(2)(iv)(A) to report an invalid actuation of the 'B' train High Head Safety Injection Pump (3SIH*P1B), the 'B' train Low Pressure Safety Injection Pump (3RHS*P1B) and four Steam Generator Blowdown Containment isolation valves at Millstone Nuclear Power Station Unit 3.
"At 1908 EST on November 6, 2020, with Unit 3 in Mode 3, a partial invalid actuation of 'B' train Emergency Core Cooling System (ECCS) components occurred. The 'B' train SIH pump and the 'B' train RHS pump had started, and ran successfully on recirculation. Four Steam Generator Blowdown Containment isolation valves also closed. Due to this condition the 'B' Emergency Diesel Generator and the 'B' Emergency Generator Load Sequencer (EGLS) were declared inoperable and the required Technical Specification action statements were entered. Troubleshooting determined that this actuation was caused by a failure of one of the circuit boards in the 'B' train EGLS that caused a partial 'B' train 'SIS only' signal. Other 'B' Train components received the 'SIS only' signal but did not start because they were already running or were a backup to an already running component. Troubleshooting discovered a failed NAND gate on the 'B' Train EGLS XA93 circuit card. The card was replaced, retested, and the Technical Specification action statements were exited.
"The pumps and valves responded in accordance with plant design. No other equipment was affected during this event.
"There were no safety consequences or impacts on the health and safety of the public. The event was entered into the station's corrective action program.
"The actuation was not due to actual plant conditions or parameters meeting design criteria for an ECCS actuation. Therefore, this is considered an invalid actuation.
"The NRC Resident Inspector was notified."
"This 60-day telephone notification is being submitted in accordance with paragraphs 10 CFR 50.73(a)(1) and 50.73(a)(2)(iv)(A) to report an invalid actuation of the 'B' train High Head Safety Injection Pump (3SIH*P1B), the 'B' train Low Pressure Safety Injection Pump (3RHS*P1B) and four Steam Generator Blowdown Containment isolation valves at Millstone Nuclear Power Station Unit 3.
"At 1908 EST on November 6, 2020, with Unit 3 in Mode 3, a partial invalid actuation of 'B' train Emergency Core Cooling System (ECCS) components occurred. The 'B' train SIH pump and the 'B' train RHS pump had started, and ran successfully on recirculation. Four Steam Generator Blowdown Containment isolation valves also closed. Due to this condition the 'B' Emergency Diesel Generator and the 'B' Emergency Generator Load Sequencer (EGLS) were declared inoperable and the required Technical Specification action statements were entered. Troubleshooting determined that this actuation was caused by a failure of one of the circuit boards in the 'B' train EGLS that caused a partial 'B' train 'SIS only' signal. Other 'B' Train components received the 'SIS only' signal but did not start because they were already running or were a backup to an already running component. Troubleshooting discovered a failed NAND gate on the 'B' Train EGLS XA93 circuit card. The card was replaced, retested, and the Technical Specification action statements were exited.
"The pumps and valves responded in accordance with plant design. No other equipment was affected during this event.
"There were no safety consequences or impacts on the health and safety of the public. The event was entered into the station's corrective action program.
"The actuation was not due to actual plant conditions or parameters meeting design criteria for an ECCS actuation. Therefore, this is considered an invalid actuation.
"The NRC Resident Inspector was notified."