Event Notification Report for November 01, 2023
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
10/31/2023 - 11/01/2023
Power Reactor
Event Number: 56897
Facility: Hatch
Region: 2 State: GA
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: David Hutto
HQ OPS Officer: Ian Howard
Region: 2 State: GA
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: David Hutto
HQ OPS Officer: Ian Howard
Notification Date: 12/18/2023
Notification Time: 13:34 [ET]
Event Date: 11/01/2023
Event Time: 20:11 [EST]
Last Update Date: 12/18/2023
Notification Time: 13:34 [ET]
Event Date: 11/01/2023
Event Time: 20:11 [EST]
Last Update Date: 12/18/2023
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):
Miller, Mark (R2DO)
Miller, Mark (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | N | 0 | Hot Shutdown | 100 | Power Operation |
60 DAY NOTIFICATION FOR AN INVALID SPECIFIED SYSTEM ACTUATION
The following information was provided by the licensee via email and phone:
"At 2011 EDT on 11/01/23, with Unit 2 in Mode 3 at 0 percent power, Unit 2 received multiple spurious actuations. These actuations consisted of a partial group 1 and a partial group 5 primary containment isolation and a partial secondary containment isolation. The partial Group 1 isolation resulted in the closure of two main steam isolation valves (MSIVs); all other MSIVs were already closed. The partial group 5 isolation auto closed one of the reactor water cleanup (RWCU) isolation valves. The partial secondary containment isolation resulted in the closure of the inboard refueling floor and reactor building secondary containment isolation valves (SCIVs).
"Additionally, at 2238 EDT, Unit 2 again received multiple spurious actuations. These actuations consisted of a partial group 5 primary containment isolation and a partial secondary containment isolation. The partial group 5 isolation auto closed one of the RWCU isolation valves The partial secondary containment isolation resulted in the closure of the inboard refueling floor and reactor building SCIVs.
"And again, at 2354 EDT, Unit 2 received spurious actuations which consisted of a partial secondary containment isolation which resulted in the closure of the inboard refueling floor and reactor building SCIVs.
"The spurious actuations seen on 11/1/23 are triggered at -35 inches reactor water level (RWL) for group 5 and secondary containment isolations and at -101 inches RWL for group 1 isolations. It was determined that a combination of the RWL fluctuating above and below the wide range instrument reference leg tap, the reactor vessel pressure being lowered, and reactor core isolation cooling introducing colder water conditions near the reference leg tap of the wide range instrument caused the spurious actuations. Using multiple RWL indications for each of the instances mentioned above, the actuations were confirmed to be spurious as RWL was being controlled in a band of +55 inches to +85 inches at the time of the actuations.
"This event is being reported in accordance with 10 CFR 50.73(a)(2)(iv)(A) as an event that resulted in an invalid actuation of a partial group 1, a partial group 5, and partial secondary containment logic."
The NRC Resident has been notified.
The following information was provided by the licensee via email and phone:
"At 2011 EDT on 11/01/23, with Unit 2 in Mode 3 at 0 percent power, Unit 2 received multiple spurious actuations. These actuations consisted of a partial group 1 and a partial group 5 primary containment isolation and a partial secondary containment isolation. The partial Group 1 isolation resulted in the closure of two main steam isolation valves (MSIVs); all other MSIVs were already closed. The partial group 5 isolation auto closed one of the reactor water cleanup (RWCU) isolation valves. The partial secondary containment isolation resulted in the closure of the inboard refueling floor and reactor building secondary containment isolation valves (SCIVs).
"Additionally, at 2238 EDT, Unit 2 again received multiple spurious actuations. These actuations consisted of a partial group 5 primary containment isolation and a partial secondary containment isolation. The partial group 5 isolation auto closed one of the RWCU isolation valves The partial secondary containment isolation resulted in the closure of the inboard refueling floor and reactor building SCIVs.
"And again, at 2354 EDT, Unit 2 received spurious actuations which consisted of a partial secondary containment isolation which resulted in the closure of the inboard refueling floor and reactor building SCIVs.
"The spurious actuations seen on 11/1/23 are triggered at -35 inches reactor water level (RWL) for group 5 and secondary containment isolations and at -101 inches RWL for group 1 isolations. It was determined that a combination of the RWL fluctuating above and below the wide range instrument reference leg tap, the reactor vessel pressure being lowered, and reactor core isolation cooling introducing colder water conditions near the reference leg tap of the wide range instrument caused the spurious actuations. Using multiple RWL indications for each of the instances mentioned above, the actuations were confirmed to be spurious as RWL was being controlled in a band of +55 inches to +85 inches at the time of the actuations.
"This event is being reported in accordance with 10 CFR 50.73(a)(2)(iv)(A) as an event that resulted in an invalid actuation of a partial group 1, a partial group 5, and partial secondary containment logic."
The NRC Resident has been notified.
Power Reactor
Event Number: 56826
Facility: Hatch
Region: 2 State: GA
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: David Hutto
HQ OPS Officer: Karen Cotton-Gross
Region: 2 State: GA
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: David Hutto
HQ OPS Officer: Karen Cotton-Gross
Notification Date: 11/01/2023
Notification Time: 09:38 [ET]
Event Date: 11/01/2023
Event Time: 06:48 [EDT]
Last Update Date: 11/01/2023
Notification Time: 09:38 [ET]
Event Date: 11/01/2023
Event Time: 06:48 [EDT]
Last Update Date: 11/01/2023
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(2)(iv)(A) - ECCS Injection 50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
10 CFR Section:
50.72(b)(2)(iv)(A) - ECCS Injection 50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
Person (Organization):
Miller, Mark (R2DO)
Felts, Russell (NRR EO)
Grant, Jeffery (IR)
Miller, Mark (R2DO)
Felts, Russell (NRR EO)
Grant, Jeffery (IR)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | M/R | Y | 56 | Power Operation | 0 | Hot Shutdown |
MANUAL REACTOR TRIP DUE TO TRIP OF REACTOR FEED PUMP
The following information was provided by the licensee via email:
"At 0648 EDT on 11/1/23, with Unit 2 in MODE 1 at 56 percent power, the reactor was manually tripped due to a trip of the 'B' reactor feed pump (RFP). The 'A' RFP had been previously isolated due to a leak. Closure of containment isolation valves (CIVs) in multiple systems and the actuation of high pressure coolant injection (HPCI) and reactor core isolation cooling (RCIC) occurred as a result of reaching the actuation setpoint on reactor water level as designed. The trip was not complex, with all safety systems responding normally post-trip.
"Operations responded and stabilized the plant. Reactor water level is being maintained with RCIC. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. Unit 1 was not affected.
"Due to the emergency core cooling system (ECCS) discharging into the reactor this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(A). Also, the reactor protection system actuation while critical is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). Additionally, it is reportable under 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of CIVs, RCIC and HPCI.
"There was no impact on the health and safety of the public or plant personnel."
The Resident Inspector was notified.
The following information was provided by the licensee via email:
"At 0648 EDT on 11/1/23, with Unit 2 in MODE 1 at 56 percent power, the reactor was manually tripped due to a trip of the 'B' reactor feed pump (RFP). The 'A' RFP had been previously isolated due to a leak. Closure of containment isolation valves (CIVs) in multiple systems and the actuation of high pressure coolant injection (HPCI) and reactor core isolation cooling (RCIC) occurred as a result of reaching the actuation setpoint on reactor water level as designed. The trip was not complex, with all safety systems responding normally post-trip.
"Operations responded and stabilized the plant. Reactor water level is being maintained with RCIC. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. Unit 1 was not affected.
"Due to the emergency core cooling system (ECCS) discharging into the reactor this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(A). Also, the reactor protection system actuation while critical is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). Additionally, it is reportable under 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of CIVs, RCIC and HPCI.
"There was no impact on the health and safety of the public or plant personnel."
The Resident Inspector was notified.
Power Reactor
Event Number: 56827
Facility: Prairie Island
Region: 3 State: MN
Unit: [1] [2] []
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: Timothy Thomas
HQ OPS Officer: Thomas Herrity
Region: 3 State: MN
Unit: [1] [2] []
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: Timothy Thomas
HQ OPS Officer: Thomas Herrity
Notification Date: 11/01/2023
Notification Time: 16:52 [ET]
Event Date: 11/01/2023
Event Time: 16:52 [CDT]
Last Update Date: 11/01/2023
Notification Time: 16:52 [ET]
Event Date: 11/01/2023
Event Time: 16:52 [CDT]
Last Update Date: 11/01/2023
Emergency Class: Non Emergency
10 CFR Section:
26.719 - Fitness For Duty
10 CFR Section:
26.719 - Fitness For Duty
Person (Organization):
Ruiz, Robert (R3DO)
Ruiz, Robert (R3DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Cold Shutdown | 0 | Cold Shutdown |
| 2 | N | N | 0 | Refueling | 0 | Refueling |
CONTROLLED SUBSTANCE FOUND IN PROTECTED AREA
The following information was provided by the licensee via email:
"On October 31 at 1856 CDT, Prairie Island Nuclear Generating Plant personnel identified a prohibited item (alcohol) in a kitchen area located within the protected area. An 'Extent of Condition' search was performed of all other protected area kitchen areas, no additional prohibited items were found.
"The NRC Resident has been notified."
The following information was provided by the licensee via email:
"On October 31 at 1856 CDT, Prairie Island Nuclear Generating Plant personnel identified a prohibited item (alcohol) in a kitchen area located within the protected area. An 'Extent of Condition' search was performed of all other protected area kitchen areas, no additional prohibited items were found.
"The NRC Resident has been notified."