Event Notification Report for April 30, 2025

EN Revision Imported Date: 4/30/2025

EN Revision Text: AGREEMENT STATE REPORT - MEDICAL EVENT

The following report was received by the Pennsylvania Bureau of Radiation Protection [the Department] via email:

"On April 16, 2025, a patient was receiving an iridium-192 treatment using an Elekta, Inc. microSelectron HDR [high-dose remote afterloader]. During the procedure, a software error that retracted the source occurred. The unit was rebooted, and the treatment was restarted. However, 17 seconds into restarting, the unit failed to show the next dwell position, so the treatment was terminated. Approximately 48 percent of the prescribed dose was administered to the patient. No harm is expected to the patient and both the physician and patient were notified. The patient treatment plan will be updated accordingly.

"The official cause is still under investigation. The service engineer will be onsite April 17, 2025, to troubleshoot the HDR. The Department will perform a reactive inspection. More information will be provided as received."

Pennsylvania Event Report Number: PA250004

* * * RETRACTION ON 04/29/2025 AT 1254 EDT FROM JOHN S. CHIPPO TO TROY JOHNSON * * *

The following report was received by the Pennsylvania Bureau of Radiation Protection via email:

"On April 16, 2025, a patient was receiving an iridium-192 treatment using an Elekta, Inc. microSelectron HDR 106.990 [high-dose remote afterloader]. Initially, it was reported that they received 48 percent of the fractionated dose prescribed, however, an Elekta service engineer was onsite on April 17, 2025, to troubleshoot the HDR. They determined that, based on the true delivery time, verified via machine detailed logfiles, the patient received 73 percent of the planned treatment dose during this fraction (the patient was prescribed 7.0 Gy and received 5.1 Gy). Since the patient dose for this fraction delivered did not differ from the prescribed dose by 50 percent or more, this event does not meet the qualifications for reporting."

Notified R1DO (Lally), and NMSS Events Notification (email)

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 - LOST OR STOLEN DENSITY GAUGE

The following report was received by the California Radiation Control Program (the Agency) via email:

"On April 21, 2025, the licensee's radiation safety officer (RSO) contacted the Agency to report the theft of a Troxler 3440 moisture density gauge, serial number 31320. The theft occurred on April 20, 2025, at 2240 PDT at a jobsite in Los Angeles, California. The Los Angeles Police Department was contacted, and a police report was filed. The Troxler gauge contains an 8 mCi cesium-137 sealed source and a 40 mCi americium-241/Be sealed source. The investigation is ongoing."

California 5010 Number: 042125

THIS MATERIAL EVENT CONTAINS A 'Less than Cat 3' LEVEL OF RADIOACTIVE MATERIAL

Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf

EN Revision Imported Date: 4/30/2025

EN Revision Text: LOSS OF OFF-SITE COMMUNICATION

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

"On 4/28/2025, at 1026 CDT, the National Weather Service notified Cooper Nuclear Station that the Shubert tower is disabled due to planned maintenance. The planned maintenance will continue from Monday, 4/28/2025 to Wednesday, 4/30/2025. This constitutes a loss of the primary public prompt notification system for greater than 24 hours. The Shubert tower transmitter activates the emergency alert system/tone alert radios used for public notification. The backup notification system has been verified to be available for use, if needed, throughout this period. This condition is reportable under 10 CFR 50.72(b)(3)(xiii) as a major loss of the public prompt notification system capability since the backup alert methods do not meet the primary systems design objective.

"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 National Weather Service notified the local authorities that the Shubert tower is disabled due to planned maintenance.