Event Notification Report for November 24, 2018
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
11/23/2018 - 11/24/2018
Power Reactor
Event Number: 53751
Facility: SEQUOYAH
Region: 2 State: TN
Unit: [1] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: MATTHEW JUNGELS
HQ OPS Officer: MARK ABRAMOVITZ
Region: 2 State: TN
Unit: [1] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: MATTHEW JUNGELS
HQ OPS Officer: MARK ABRAMOVITZ
Notification Date: 11/24/2018
Notification Time: 21:27 [ET]
Event Date: 11/24/2018
Event Time: 00:00 [EST]
Last Update Date: 11/24/2018
Notification Time: 21:27 [ET]
Event Date: 11/24/2018
Event Time: 00:00 [EST]
Last Update Date: 11/24/2018
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(C) - POT UNCNTRL RAD REL 50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
10 CFR Section:
50.72(b)(3)(v)(C) - POT UNCNTRL RAD REL 50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
Person (Organization):
STEVE ROSE (R2DO)
STEVE ROSE (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
| 2 | N | N | 0 | Cold Shutdown | 0 | Cold Shutdown |
AUXILIARY BUILDING DOOR BLOCKED OPEN
"At 1420 [EST] on November 24, 2018, operators discovered that a door was blocked open creating a breach of the auxiliary building secondary containment enclosure (ABSCE) boundary that exceeded the allowed ABSCE breach margin [of three minutes]. As a result, Unit 1 entered Technical Specification Limiting Condition of Operation (LCO) 3.7.12 Condition B for two trains of Auxiliary Building Gas Treatment System (ABGTS) inoperable due to an inoperable ABSCE boundary in MODE 1, 2, 3, or 4, and both Units entered Condition E for one required ABGTS train inoperable with fuel stored in the spent fuel pool.
"In MODES 1, 2, 3, and 4, the analysis of the loss of coolant accident (LOCA) assumes that radioactive materials leaked from the Emergency Core Cooling System are filtered and absorbed by the ABGTS. For the fuel handling accident, the analysis assumes that the ABSCE boundary is capable of being established to ensure releases from the auxiliary and containment buildings are consistent with the dose consequence analysis.
"The event is reportable in accordance with 10 CFR 50.72(b)(3)(v) as an event or condition that could have prevented fulfillment of the safety function of structures or systems that are needed to: (C) control the release of radioactive material and (D) mitigate the consequences of an accident.
"No actual LOCA or fuel handling accident occurred while both trains of ABGTS were inoperable. The condition had no impact on the health and safety of the public.
"The NRC Resident Inspector has been notified."
This situation occurred because of maintenance activities. A breeching permit had been initiated however, the required personnel to ensure the door could be closed within the required three minutes were not assigned. The door was closed approximately 15 minutes after the situation was noticed.
"At 1420 [EST] on November 24, 2018, operators discovered that a door was blocked open creating a breach of the auxiliary building secondary containment enclosure (ABSCE) boundary that exceeded the allowed ABSCE breach margin [of three minutes]. As a result, Unit 1 entered Technical Specification Limiting Condition of Operation (LCO) 3.7.12 Condition B for two trains of Auxiliary Building Gas Treatment System (ABGTS) inoperable due to an inoperable ABSCE boundary in MODE 1, 2, 3, or 4, and both Units entered Condition E for one required ABGTS train inoperable with fuel stored in the spent fuel pool.
"In MODES 1, 2, 3, and 4, the analysis of the loss of coolant accident (LOCA) assumes that radioactive materials leaked from the Emergency Core Cooling System are filtered and absorbed by the ABGTS. For the fuel handling accident, the analysis assumes that the ABSCE boundary is capable of being established to ensure releases from the auxiliary and containment buildings are consistent with the dose consequence analysis.
"The event is reportable in accordance with 10 CFR 50.72(b)(3)(v) as an event or condition that could have prevented fulfillment of the safety function of structures or systems that are needed to: (C) control the release of radioactive material and (D) mitigate the consequences of an accident.
"No actual LOCA or fuel handling accident occurred while both trains of ABGTS were inoperable. The condition had no impact on the health and safety of the public.
"The NRC Resident Inspector has been notified."
This situation occurred because of maintenance activities. A breeching permit had been initiated however, the required personnel to ensure the door could be closed within the required three minutes were not assigned. The door was closed approximately 15 minutes after the situation was noticed.
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 53752
Facility: MILLSTONE
Region: 1 State: CT
Unit: [] [2] []
RX Type: [1] GE-3,[2] CE,[3] W-4-LP
NRC Notified By: RYAN ROBILLARD
HQ OPS Officer: DAN LIVERMORE
Region: 1 State: CT
Unit: [] [2] []
RX Type: [1] GE-3,[2] CE,[3] W-4-LP
NRC Notified By: RYAN ROBILLARD
HQ OPS Officer: DAN LIVERMORE
Notification Date: 11/25/2018
Notification Time: 02:47 [ET]
Event Date: 11/24/2018
Event Time: 20:15 [EST]
Last Update Date: 01/18/2019
Notification Time: 02:47 [ET]
Event Date: 11/24/2018
Event Time: 20:15 [EST]
Last Update Date: 01/18/2019
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):
RAY POWELL (R1DO)
RAY POWELL (R1DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | N | 0 | Cold Shutdown | 0 | Cold Shutdown |
LOSS OF CONTROL ROOM ENVELOPE DUE TO DOOR FAILURE
"On 11/24/18 at 2015 EST, a loss of Control Room Envelope (CRE) was declared due to failure of the control room boundary door, 204-36-008. [Abnormal Operating Procedure 8588A Mitigating Actions for Control Boundary Breach was implemented]. The door was repaired at 2030 EST, restoring CRE to operable [status]."
A mechanical failure of the control room door latch prevented the door from closing.
The licensee notified the NRC Resident Inspector.
* * * RETRACTION ON 01/18/19 AT 1457 EST FROM GARY CLOSIUS TO JEFFREY WHITED * * *
"The purpose of this call is to retract a report made on November 25, 2018, NRC Event Number EN53752.
"NRC Event Report number EN53752 describes a condition at Millstone Power Station Unit 2 (MPS2) in which a control room envelope boundary door was discovered to not be able to fully close due to the latching mechanism being stuck in the extended position.
"The condition was reported to the NRC pursuant to 10 CFR 50.72(b)(3)(v)(D) via an 8-hour prompt report as an event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident.
"Upon further review, MPS2 determined that there was no loss of safety function. An engineering evaluation determined that even with the control room boundary door unable to be fully closed due to the latching mechanism being stuck in the extended position, control room air in-leakage would not have been sufficient to prevent the control room emergency ventilation system from performing its safety function.
"Therefore, this condition is not reportable and NRC Event Number EN53752 is being retracted.
"The basis for this conclusion has been provided to the NRC Resident Inspector."
Notified the R1DO (Carfang).
"On 11/24/18 at 2015 EST, a loss of Control Room Envelope (CRE) was declared due to failure of the control room boundary door, 204-36-008. [Abnormal Operating Procedure 8588A Mitigating Actions for Control Boundary Breach was implemented]. The door was repaired at 2030 EST, restoring CRE to operable [status]."
A mechanical failure of the control room door latch prevented the door from closing.
The licensee notified the NRC Resident Inspector.
* * * RETRACTION ON 01/18/19 AT 1457 EST FROM GARY CLOSIUS TO JEFFREY WHITED * * *
"The purpose of this call is to retract a report made on November 25, 2018, NRC Event Number EN53752.
"NRC Event Report number EN53752 describes a condition at Millstone Power Station Unit 2 (MPS2) in which a control room envelope boundary door was discovered to not be able to fully close due to the latching mechanism being stuck in the extended position.
"The condition was reported to the NRC pursuant to 10 CFR 50.72(b)(3)(v)(D) via an 8-hour prompt report as an event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident.
"Upon further review, MPS2 determined that there was no loss of safety function. An engineering evaluation determined that even with the control room boundary door unable to be fully closed due to the latching mechanism being stuck in the extended position, control room air in-leakage would not have been sufficient to prevent the control room emergency ventilation system from performing its safety function.
"Therefore, this condition is not reportable and NRC Event Number EN53752 is being retracted.
"The basis for this conclusion has been provided to the NRC Resident Inspector."
Notified the R1DO (Carfang).