Event Notification Report for February 29, 2024

AGREEMENT STATE REPORT - PATIENT RECEIVED LESS THAN PRESCRIBED DOSE

The following report was received via email from the Alabama Department of Public Health, Office of Radiation Control (the Office):

"The Office was notified of the medical event during a licensee inspection between February 6 to February 8, 2024. The licensee reported that during a patient's 3rd treatment on 12/4/2023, dwell positions in part of the high dose rate (HDR) applicator (2 ovoids) were successfully completed. Dwell positions in another part of the applicator (the tandem) were interrupted due to an obstruction. After repeated checks and attempts, dwell positions in the tandem could not be completed. The patient received 100 cGy of the intended 600 cGy for the third treatment on 12/4/2023.

"The licensee examined the applicator, and determined that there appeared to be microfractures in the area of the tandem. The licensee has replaced this applicator, and developed precautionary safety procedures to avoid this matter in the future. The licensee noted that the matter appears to be related to the autoclaving process for applicators. The licensee also revised the patient's treatment course, and the patient was successfully treated during 4th and 5th fractions.

"The licensee used an Elekta Flexitron serial number: FT00306, with an Alpha-Omega model 136147 source, serial number: D85F-2336, 11.86 Ci of Ir-192 on 11/17/2023."

Alabama Incident Number: Pending

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.

AGREEMENT STATE REPORT - DISCOVERY OF AN ORPHAN RADIOACTIVE SOURCE

The following information was provided by the Washington State Department of Health via email:

"Port Townsend Paper Corporation sent an old lead-lined tank to a scrap yard. Unknown radioactivity was then detected in the tank at the scrap yard. The unknown radioactive material was wrapped in lead from the tank by workers at the scrap yard and sent back to Port Townsend Paper Corporation. The Radiation Safety Officer at Port Townsend Paper Corporation measured 0.33 mR/hour on the outside of the lead. The lead and the unknown radioactive material were temporarily stored in an area of the paper mill that is usually unoccupied.

"An inspector from the Washington State Department of Health plans to go to the Port Townsend Paper Corporation in a few days to investigate. It is suspected that the unknown radioactivity is likely to be naturally occurring radioactive material which can build up over time in piping, tanks, etc. at paper mill facilities. All the licensee's sealed sources are accounted for, so the unknown radioactivity is unlikely to be from one of them, but the inspector will check for that possibility."

WA Event Number: WA-24-005

AUTOMATIC REACTOR SCRAM

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

"At approximately 0839 [CST] with Unit 1 in Mode 1 at 100 percent power, the reactor automatically scrammed due to the depressurization of the SCRAM air header caused by an invalid signal that [occurred] during system testing. The SCRAM was uncomplicated with all systems responding as expected. The cause and details of the event are under investigation. Containment isolation valves actuated and closed on a valid Group 2 signal.

"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), and an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) for the Group 2 isolation signal.

"Operations responded using the emergency operating procedure and stabilized the plant in Mode 3. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves.

"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. State as well as Wright and Sherburne Counties will be notified."

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

The Anticipated Transient Without Scram (ATWS) circuit was being tested when an invalid signal was sent to depressurize the SCRAM air header.

SPECIFIED SYSTEM ACTUATION - AUTOMATIC START OF EMERGENCY DIESEL GENERATORS

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

"At 1350 EST on 2/28/2024, with Calvert Cliffs Unit 1 in Mode 5 at 0 percent power and Unit 2 in Mode 1 at 65 percent power, an actuation of the '1A' and '2A' emergency diesel generators' auto-start occurred due to an undervoltage condition on the number 11 and number 21 4kV buses which are fed from the number 11 13kV bus. The '1A' and '2A' emergency diesel generators automatically started as designed when the 4kV buses' undervoltage signals were received.

"This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in a valid actuation of the '1A' and '2A' emergency diesel generators.

"There was no impact on the health and safety of the public or plant personnel."

The NRC Resident Inspector has been notified.

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

The undervoltage condition was caused by the feeder breaker to the number 11 13 kV bus opening during electrical maintenance.