Event Notification Report for June 05, 2024

STUCK SHUTTER

The following is a summary of information obtained from the licensee via phone:

The assistant radiation safety officer (ARSO) received a notification from their Tilden Mine site that a Ohmart Vega (model SH-F1B-0) containing 1 mCi of Cs-137 had a stuck open shutter. The ARSO is evaluating whether to contact Vega to schedule a technician to service the shutter or to amend their NRC license to allow them to service the shutter. The nuclear gauge is in a location inaccessible to personnel and there is no additional exposure risk to personnel or the public.

AGREEMENT STATE REPORT - DAMAGED MOISTURE DENSITY GAUGE

The following is a synopsis of information provided by the Florida Bureau of Radiation Control (BRC) via email and phone:

At 1138 EDT, the radiation safety officer reported that a Troxler gauge was run over by construction equipment. The initial report was that the source did not retract as a result of the damage. The BRC inspector should be prepared to conduct contamination surveys for source leakage and provide guidance on transporting the damaged gauge safely.

Gauge Information
Make: Troxler
Activity: 8 mCi Cs-137, 40 mCi Am-241:Be

Florida Incident No.: FL24-039

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:

The gauge was successfully retracted by the BRC inspector and there was no additional personnel exposure from the damaged gauge.


* * * UPDATE ON 5/31/2024 AT 1146 EDT FROM MONROE COOPER TO ERNEST WEST * * *

"A [BRC] inspector responded. The source rod was successfully retracted, contamination swipes were performed on the gauge, and a survey was performed at the location of the accident; no elevated swipes or readings were observed. The gauge was maintained by licensee who will be transporting it to Troxler for evaluation."

Notified R1DO (DeFrancisco) and NMSS Events via email

AUTOMATIC ACTUATION OF EMERGENCY FEEDWATER SYSTEM

The following information was provided by the licensee via phone and email:

"At 0051 EDT on June 3, 2024, with Unit 3 in Mode 3 at 0 percent power, an actuation of the emergency feedwater system (EFW) occurred as main steam pressure was being lowered as part of reactor coolant system (RCS) cooldown for a planned shutdown. The reason for the EFW auto-start was lowering levels in the 3A and 3B steam generators following loss of the operating main feedwater pump. The main feedwater pump automatically tripped when main steam pressure was lowered below the automatic feedwater isolation system (AFIS) actuation setpoint before AFIS channels were taken to bypass. The 3A and 3B motor driven emergency feedwater pumps automatically started as designed when the 'low steam generator level' signal was received for the 3A and 3B steam generators.

"This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the EFW system.

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

EN Revision Imported Date: 6/6/2024

EN Revision Text: MANUAL REACTOR TRIP

The following information was provided by the licensee via email:

"At 1352 EDT, on June 4, 2024 with Unit 2 at 92 percent power, the reactor was manually tripped due to a loss of condenser vacuum resulting from a circulating water pump trip. The trip was uncomplicated with all systems responding normally post trip. Operations stabilized the plant in mode 3. Decay heat is being removed by steam discharge to the main condenser using the turbine bypass valves. St. Lucie Unit 1 was not affected and remains at 100 percent power.

"This event is being reported pursuant to 10 CFR 50.72 (b)(2)(iv)(B).

"The NRC Resident Inspector has been notified."