Event Notification Report for August 22, 2023

AGREEMENT STATE REPORT - STUCK SHUTTERS

The following is a synopsis of information received from Maine Radiation Control Program via telephone:

The licensee was in the process of shutting down the plant when it was discovered that 4 level gauges on one tank have stuck open shutters. The model and activity are not available at this time. Due to the location of the gauges, no exposures were recorded nor are any expected. This investigation for the stuck open shutters is on going.

MEDICAL EVENT - PATIENT UNDERDOSE

The following is a summary of information provided by the licensee via phone:

A patient underwent an eye plaque procedure where they were to receive 85 Gy of Iodine-125 over a seven day period. The patient received an estimated dose of 57 Gy. The total dose delivered differs from the prescribed dose by greater than 20 percent. The licensee believed the seed could have shifted during the 7 days. A written report will be forwarded when complete.

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.

TECHNICAL SPECIFICATION REQUIRED SHUTDOWN

The following information was provided by the licensee via email:

"On 8/20/2023 at 1600 EDT, during plant walkdowns in the drywell while in mode 3 to identify a cause of increasing unidentified leakage rate, reactor coolant system pressure boundary leakage (approximately 2 gpm) was identified on the reactor recirculation sample line between the reactor recirculation sample line inboard isolation valve (B3100F019) and where the sample line taps off the B reactor recirculation jet pump riser. This requires entry into technical specification 3.4.4 condition C, identification of pressure boundary leakage with a required action to be in mode 3 in 12 hours and mode 4 in 36 hours. At 1630 EDT, a technical specification required shutdown to mode 4, cold shutdown, was initiated.

"A press release by DTE is anticipated. This event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(i), a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(xi), and an eight-hour, non-emergency notification 10 CFR 50.72(b)(3)(ii)(A) for the degraded condition of the pressure boundary.

"Investigation into the cause of the reactor coolant system pressure boundary leakage is still ongoing.

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