WASHINGTON, Jan. 24 -- The Nuclear Regulatory Commission issued the following event notification (No. 55708) involving Monticello Nuclear Plant, Minnesota:
INVALID ACTUATION OF SECONDARY CONTAINMENT RELAYS
The following information was provided by the licensee via email:
"This telephone notification is provided in accordance with 10 CFR 50.73(a)(1) to report an invalid actuation of secondary containment relays in accordance with 10 CFR 50.73(a)(2)(iv)(A).
"On November 29, 2021, the `B' Fuel Pool radiation monitor spiked high during restoration following the performance of the 0068 procedure `Spent Fuel Pool & Reactor Building Exhaust Plenum Monitor Calibration' due to cable to radiation monitor connector degradation from handling. This resulted in a Partial Primary Containment Group II isolation (gas systems), initiation of Standby Gas Treatment system, and isolation of the Reactor Building Ventilation system.
"All systems responded as designed to the actuation signal. Operations reset the Partial Primary Containment Group II isolation signal, shutdown Standby Gas Treatment System, and restored Reactor Building Ventilation system per procedures.
"At the time of the occurrence, the `A' Fuel Pool radiation monitor was reading normal at approximately 1.5 mr/hr. The `B' Fuel Pool radiation monitor spiked above the 50 mr/hr setpoint and continued to read erratically. Work was performed to clean and reconnect the connector and testing per 0068 procedure verified the condition was corrected. The `B' Fuel Pool radiation monitor returned to service.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
Event Number: 55708
Unit:   
RX Type:  GE-3
NRC Notified By: Jason Brevig
HQ OPS Officer: Mike Stafford
Notification Date: 01/21/2022
Notification Time: 10:25 [ET]
Event Date: 11/29/2021
Event Time: 11:28 [CST]
Last Update Date: 01/21/2022
Emergency Class: Non Emergency
10 CFR Section:
50.73(a)(1) - Invalid Specif System Actuation
Stoedter, Karla (R3)
Table omitted: https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2022/2...