Event Notification Report for June 22, 2026

AGREEMENT STATE REPORT - UNPLANNED CONTAMINATION / SPILL

The following information was provided by the Illinois Emergency Management Agency (the Agency) via phone and email:

"The Agency was contacted on 6/12/26 by the radiation safety officer (RSO) at Northwestern Memorial HealthCare to advise of a spill of Xofigo Ra-223 on the morning of 6/11/26. While surveying out at the end of the day on 6/11/26, nuclear medicine staff identified contamination on the bottom of their shoes. Staff immediately changed shoes, donned shoe covers, and conducted surveys of all personnel and areas within the department to find the location of the contamination. While surveying, the red cap from a Xofigo syringe was discovered under a chair adjacent to the area where a Xofigo administration was completed earlier that day. Floor contamination was also discovered. No contamination to the skin of personnel was reported.

"Nuclear medicine staff notified the RSO in accordance with spill procedures. The RSO instructed nuclear medicine staff to close off areas where contamination was found until a full assessment could be completed by radiation safety staff the following morning. A spectral analysis of wipes taken confirmed the isotope as Ra-223. The survey record from the 1200 EDT administration of Xofigo that morning was reviewed and indicated background levels.

"Upon notification of the spill on 6/12/26, an Agency radioactive materials inspector was sent to the site to assess the scene and assist with surveys. The inspector identified additional floor contamination using a pancake probe and an alpha detector. The inspector observed personnel in the area wearing shoe covers and assisted in setting up a step-off line for survey and removal of contaminated shoe covers.

"This contamination event is reportable under Illinois Administrative Code, Title 340, Section 1220(c)(1), within 24 hours after discovery. Reporting requirements were met by the licensee. The licensee is continuing to decontaminate and survey for removable contamination. Areas identified will be decontaminated or covered with chucks pads to prevent further spread of contamination. The licensee is continuing its investigation into how the spill occurred. This report will be updated as additional information is received."

Illinois Item Number: IL260016

AGREEMENT STATE REPORT - LEAKING SEALED SOURCE

The following information was provided by the Georgia Radioactive Material Program via email:

"During a routine leak test performed on June 12, 2026, by West Physics at Heart and Vascular Care, Inc., a Cs-137 Eckert and Ziegler E-vial sealed source (original activity 206.4 microcuries, serial number: 1377-19-19) was found to contain removable contamination above the acceptable limit, indicating a potential leak. Leak test results of 0.005 microcuries or below are acceptable; the sample from this vial measured 0.0127 microcuries. A visual inspection identified cracks in the vial, although it is not known whether these cracks were the direct cause of the contamination. No other damage was observed. The radiation safety officer (RSO) was notified immediately.

"Removable contamination surveys were conducted in all areas where the source had been stored or used, and the physicist's hands were also surveyed. All samples were analyzed using the well counter, and no removable contamination was detected. The damaged vial was placed back into the lead pig, which was then sealed with tape and placed inside a plastic bag along with the gloves used and all contamination samples. This bag was then placed inside a second plastic bag, sealed with tape, and stored in the hot lab.

"The licensee is contacting waste disposal companies to arrange disposal of the source and associated waste. An update will be provided once disposal is complete."

GA Incident number: 124

AGREEMENT STATE REPORT - STOLEN GAUGE

The following is a summary of information provided by the New Jersey Department of Environmental Protection (NJDEP) via email:

On 6/13/2026, a technician's car was stolen from their driveway with a Troxler gauge stored securely in the trunk. The radiation safety officer (RSO) was notified by the technician around 1010 EDT. Local law enforcement and the FBI were notified. The RSO called NJDEP and at 1410, the RSO emailed NJDEP Bureau of Environmental Radiation (BER) staff.

Gauge Information
Model: Troxler 3440
Serial Number: 29038
Activity: 44 mCi of Am-241/Be 44 mCi; 9 mCi of Cs-137


* * * UPDATE ON 06/16/2026 AT 1617 EDT FROM CHRISTOPHER GIAQUINTO TO JOSUE RAMIREZ * * *

The following update was provided by the New Jersey Department of Environmental Protection (NJDEP) via email:

"The gauge was recovered today with no damage."

Notified R1DO (Schussler), NMSS Events Notification (email), and ILTAB (email).


NJ Report ID: 986950

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

AUTOMATIC REACTOR TRIP

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

"At 2325 [CDT] on 06/17/2026, [South Texas Project] Unit 2 reactor automatically tripped following a lockout of the Unit main and [auxiliary] transformers. This trip was not complex with all systems responding as normal post trip.

"Auxiliary feedwater actuated and standby diesel generators (DG) 21 and 23 started to carry their respective engineered safety features (ESF) busses.

"The Unit 2 balance of plant DG was out of service at the time of the trip. This issue resulted in no power to the Unit 2 instrument air compressors. The unit was cooled down utilizing steam generator pressure operated relief valves (PORV).

"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).

"There was no impact to the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. Unit 1 was unaffected by this event."

PART 21 - FUEL POOL STORAGE CRITICALITY CALCULATION ERROR

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

Westinghouse has discovered a deviation in its fuel data management system that has potential to affect the criticality calculations for fresh fuel with integral fuel burnable absorbers (IFBAs) in the spent fuel pool. The system allows the use of facility-specific curves to determine when a fresh fuel assembly with IFBAs is acceptable for storage in the spent fuel pool. When the system adjusts for an IFBA loading different from what was used to develop the facility-specific curve, there is potential for the assessment to allow storage of fuel with IFBA loading that is not encompassed by the fuel storage criticality analysis of record.

Currently, Westinghouse has not identified an existing condition where the system has allowed fuel to be stored in a manner that is not encompassed by the fuel storage criticality analysis of record for the potentially impacted plants listed below. The affected customers have been notified. Westinghouse expects to complete its 10 CFR Part 21 evaluation on or before September 30, 2026.

The following plants are potentially affected: Cook, Diablo Canyon, Farley, Millstone, Point Beach, Salem, Turkey Point, Summer, South Texas, Vogtle, Wolf Creek

Designated contact:
Andrew Bowman
Manager, Global Nuclear Regulatory Affairs
Westinghouse Electric Company
1000 Westinghouse Drive
Cranberry Township, PA
Email: bowmanab@westinghouse.com
Office: 412-374-2363