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Event Notification Report for March 17, 2021

U.S. Nuclear Regulatory Commission
Operations Center

EVENT REPORTS FOR
03/16/2021 - 03/17/2021

EVENT NUMBERS
5514355144
Power Reactor
Event Number: 55143
Facility: Watts Bar
Region: 2     State: TN
Unit: [2] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Robert Collins
HQ OPS Officer: Thomas Kendzia
Notification Date: 03/17/2021
Notification Time: 12:59 [ET]
Event Date: 03/17/2021
Event Time: 10:04 [EST]
Last Update Date: 03/17/2021
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
Person (Organization):
MILLER, MARK (R2)
Power Reactor Unit Info
Unit SCRAM Code RX Crit Initial PWR Initial RX Mode Current PWR Current RX Mode
2 A/R Y 90 Power Operation 0 Hot Standby
Event Text
EN Revision Imported Date: 4/16/2021

EN Revision Text: AUTOMATIC REACTOR TRIP

"At 1004 EDT on March 17, 2021, with Unit 2 in Mode 1 at 90 percent power, the reactor automatically tripped due to a main turbine trip. The trip was not complex, with all systems responding normally post-trip.

"Operations responded and stabilized the plant. Decay heat is being removed by the Auxiliary Feedwater and Steam Dump Systems. Unit 1 is not affected.

"Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). The expected actuation of the Auxiliary Feedwater System (an engineered safety feature) is being reported as an eight hour report under 10 CFR 50.72 (b)(3)(iv)(A).

"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."

All controls rods fully inserted and the electrical system is in normal shutdown alignment. The cause of the turbine trip is being investigated.


Non-Agreement State
Event Number: 55144
Rep Org: US STEEL CORPORATION GARY WORKS
Licensee: US STEEL CORPORATION GARY WORKS
Region: 3
City: Gary   State: IN
County:
License #: 13-26-104-03
Agreement: N
Docket:
NRC Notified By: Shakeia Reese
HQ OPS Officer: Lloyd Desotell
Notification Date: 03/18/2021
Notification Time: 13:57 [ET]
Event Date: 03/17/2021
Event Time: 13:00 [CST]
Last Update Date: 03/18/2021
Emergency Class: Non Emergency
10 CFR Section:
30.50(b)(2) - Safety Equipment Failure
Person (Organization):
JOHN HANNA (R3DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
Event Text
EN Revision Imported Date: 4/16/2021

EN Revision Text: GAUGE STUCK SHUTTER

The following is a summary from a phone notification received from the licensee:

Maintenance technicians performing a lockout for maintenance manipulated a moisture gauge shutter handle and the handle broke, rendering the shutter stuck in the open position. The normal position for the shutter is open. The maintenance was canceled and the area around the gauge was secured. The gauge manufacture has been contacted and will be out to the site to help the licensee repair the gauge on 3/23/21. No exposure to personnel resulted from this event.

The gauge measures the moisture content in a bin containing metallurgical coke. The Berthold [TM] gauge contains a 300 mCi Am-241/Be source.