Event Notification Report for November 27, 2018
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
11/26/2018 - 11/27/2018
EVENT NUMBERS
53756
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 53756
Facility: RIVER BEND
Region: 4 State: LA
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: T. W. GATES
HQ OPS Officer: THOMAS KENDZIA
Region: 4 State: LA
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: T. W. GATES
HQ OPS Officer: THOMAS KENDZIA
Notification Date: 11/28/2018
Notification Time: 05:40 [ET]
Event Date: 11/27/2018
Event Time: 00:00 [CST]
Last Update Date: 12/03/2018
Notification Time: 05:40 [ET]
Event Date: 11/27/2018
Event Time: 00:00 [CST]
Last Update Date: 12/03/2018
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(C) - POT UNCNTRL RAD REL
10 CFR Section:
50.72(b)(3)(v)(C) - POT UNCNTRL RAD REL
Person (Organization):
JASON KOZAL (R4DO)
JASON KOZAL (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 99 | Power Operation | 99 | Power Operation |
INOPERABILITY OF EQUIPMENT FOR CONTROL OF RADIOLOGICAL RELEASE
"At 2130 CST on 11/27/2018, Division 1 Main Steam Positive Leakage Control System (MS-PLCS) was declared inoperable because of a leaking check valve that caused excessive cycling of the associated air compressor.
"Division 2 MS-PLCS had been declared inoperable on 11/27/2018 at 1400 CST when a pressure control valve in the system exceeded the maximum allowable stroke time.
"Because MS-PLCS supplements the isolation function of the main steam isolation valves (MSIVs) by processing fission products that could leak through the closed MSIVs, both divisions of MS-PLCS inoperable at the same time represents a condition that could prevent the fulfillment of a safety function of an SSC [Structures, Systems and Components] that is needed to control the release of radioactive material.
"The station diesel air compressor is available to supply backup air to the safety relief valves as required by the Technical Requirements Manual." [This is associated with operability of the safety relief valves, due to the inoperable MS-PLCS air compressor.]
The unit is in a 7 day shutdown Limiting Condition for Operation (LCO), 1-TS1-18-Div 1 & 2 MSPLCS-685, for the two divisions of MS-PLCS being inoperable.
The licensee notified the NRC Resident Inspector.
* * * RETRACTION ON 12/03/18 AT 1551 EST FROM TIM GATES TO BETHANY CECERE * * *
"This event was initially reported under 10 CFR 50.72(b)(3)(v)(C) as a condition that could have prevented the Main Steam Positive Leakage Control System (MS-PLCS) from fulfilling its safety function to control the release of radioactive material. Division I was declared inoperable due to a failed component. Division II was declared inoperable due to a pressure control valve in the system exceeding the maximum allowable time to close by 0.50 seconds. An engineering evaluation has since been performed and concluded that the 2 second maximum allowable time to close was based on the pressure control valve being classified as a rapid closure valve and was established from the original baseline data of 0.50 seconds. This baseline data is an administrative target value per the In-Service Testing Program. There are no technical specification requirements associated with the 2 second closure time.
"The engineering evaluation also determined that the volume of air supplied through the pressure control valve during the extra 0.50 seconds of valve closure would have an inconsequential effect on the pressure within the volume of leakage barrier between the Main Steam Isolation Valves associated with the MS-PLCS pressure control valve or have any effect on containment over-pressurization.
"Based on the information provided by the engineering evaluation, the Division II MS-PLCS has been declared operable-degraded non-conforming since time of initial discovery. Consequently, this event is not reportable as a condition that could have prevented the Main Steam Positive Leakage Control System (MS-PLCS) from fulfilling its safety function.
"The [NRC] Resident Inspector has been notified via e-mail."
Notified the R4DO (Gaddy).
"At 2130 CST on 11/27/2018, Division 1 Main Steam Positive Leakage Control System (MS-PLCS) was declared inoperable because of a leaking check valve that caused excessive cycling of the associated air compressor.
"Division 2 MS-PLCS had been declared inoperable on 11/27/2018 at 1400 CST when a pressure control valve in the system exceeded the maximum allowable stroke time.
"Because MS-PLCS supplements the isolation function of the main steam isolation valves (MSIVs) by processing fission products that could leak through the closed MSIVs, both divisions of MS-PLCS inoperable at the same time represents a condition that could prevent the fulfillment of a safety function of an SSC [Structures, Systems and Components] that is needed to control the release of radioactive material.
"The station diesel air compressor is available to supply backup air to the safety relief valves as required by the Technical Requirements Manual." [This is associated with operability of the safety relief valves, due to the inoperable MS-PLCS air compressor.]
The unit is in a 7 day shutdown Limiting Condition for Operation (LCO), 1-TS1-18-Div 1 & 2 MSPLCS-685, for the two divisions of MS-PLCS being inoperable.
The licensee notified the NRC Resident Inspector.
* * * RETRACTION ON 12/03/18 AT 1551 EST FROM TIM GATES TO BETHANY CECERE * * *
"This event was initially reported under 10 CFR 50.72(b)(3)(v)(C) as a condition that could have prevented the Main Steam Positive Leakage Control System (MS-PLCS) from fulfilling its safety function to control the release of radioactive material. Division I was declared inoperable due to a failed component. Division II was declared inoperable due to a pressure control valve in the system exceeding the maximum allowable time to close by 0.50 seconds. An engineering evaluation has since been performed and concluded that the 2 second maximum allowable time to close was based on the pressure control valve being classified as a rapid closure valve and was established from the original baseline data of 0.50 seconds. This baseline data is an administrative target value per the In-Service Testing Program. There are no technical specification requirements associated with the 2 second closure time.
"The engineering evaluation also determined that the volume of air supplied through the pressure control valve during the extra 0.50 seconds of valve closure would have an inconsequential effect on the pressure within the volume of leakage barrier between the Main Steam Isolation Valves associated with the MS-PLCS pressure control valve or have any effect on containment over-pressurization.
"Based on the information provided by the engineering evaluation, the Division II MS-PLCS has been declared operable-degraded non-conforming since time of initial discovery. Consequently, this event is not reportable as a condition that could have prevented the Main Steam Positive Leakage Control System (MS-PLCS) from fulfilling its safety function.
"The [NRC] Resident Inspector has been notified via e-mail."
Notified the R4DO (Gaddy).