Event Notification Report for July 25, 2023
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
07/24/2023 - 07/25/2023
EVENT NUMBERS
56637
56637
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 56637
Facility: Millstone
Region: 1 State: CT
Unit: [2] [] []
RX Type: [1] GE-3,[2] CE,[3] W-4-LP
NRC Notified By: Jason Parr
HQ OPS Officer: Thomas Herrity
Region: 1 State: CT
Unit: [2] [] []
RX Type: [1] GE-3,[2] CE,[3] W-4-LP
NRC Notified By: Jason Parr
HQ OPS Officer: Thomas Herrity
Notification Date: 07/25/2023
Notification Time: 16:06 [ET]
Event Date: 07/25/2023
Event Time: 09:24 [EDT]
Last Update Date: 09/26/2023
Notification Time: 16:06 [ET]
Event Date: 07/25/2023
Event Time: 09:24 [EDT]
Last Update Date: 09/26/2023
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(v)(D) - Accident Mitigation
10 CFR Section:
50.72(b)(3)(v)(D) - Accident Mitigation
Person (Organization):
Bickett, Carey (R1DO)
Bickett, Carey (R1DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | Y | 86 | Power Operation | 86 | Power Operation |
EN Revision Imported Date: 9/27/2023
EN Revision Text: CONTROL ROOM ENVELOPE INOPERABLE
The following information was provided by the licensee via email:
"At 0924 [EDT] on July 25, 2023, it was discovered that both trains of control room air conditioning system were simultaneously inoperable due to an inoperable control room envelope boundary. The boundary was restored at 0925 [EDT] on July 25, 2023. This condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D).
"There was no impact on the health and safety of the public or plant personnel.
"The NRC Resident Inspector has been notified.
"There has been no impact to Unit 3 which remains at 100% power."
* * * RETRACTION ON 09/26//23 AT 1305 EDT FROM PATRICK SIKORSKY TO JOHN RUSSELL * * *
The licensee determined in a subsequent engineering evaluation of the conditions that existed at the time, that the access hatch being open did not have an adverse impact upon the control room emergency ventilation system and the control room envelopes boundary's ability to perform their safety function including:
Radiation dose to the occupants did not exceed the licensing basis, design basis accident calculated value.
Protection of control room occupants from hazardous chemicals and smoke.
Therefore, this condition is not reportable and NRC Event EN56637 is being retracted. The basis for this conclusion has been provided to the NRC Resident Inspector.
Notified R1DO (Lally)
EN Revision Text: CONTROL ROOM ENVELOPE INOPERABLE
The following information was provided by the licensee via email:
"At 0924 [EDT] on July 25, 2023, it was discovered that both trains of control room air conditioning system were simultaneously inoperable due to an inoperable control room envelope boundary. The boundary was restored at 0925 [EDT] on July 25, 2023. This condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D).
"There was no impact on the health and safety of the public or plant personnel.
"The NRC Resident Inspector has been notified.
"There has been no impact to Unit 3 which remains at 100% power."
* * * RETRACTION ON 09/26//23 AT 1305 EDT FROM PATRICK SIKORSKY TO JOHN RUSSELL * * *
The licensee determined in a subsequent engineering evaluation of the conditions that existed at the time, that the access hatch being open did not have an adverse impact upon the control room emergency ventilation system and the control room envelopes boundary's ability to perform their safety function including:
Radiation dose to the occupants did not exceed the licensing basis, design basis accident calculated value.
Protection of control room occupants from hazardous chemicals and smoke.
Therefore, this condition is not reportable and NRC Event EN56637 is being retracted. The basis for this conclusion has been provided to the NRC Resident Inspector.
Notified R1DO (Lally)