Event Notification Report for July 14, 2023

AGREEMENT STATE REPORT - LOST AND RECOVERED GAUGE

The following information was provided by the Ohio Department of Health (ODH) via email:

"At approximately 1100 EDT on 6/29/23, ODH received notification from an Ohio radioactive materials licensee that a portable device containing radioactive sources had been lost. The device is a Troxler Model 3430 portable moisture/density gauge containing an 8 millicurie Cesium-137 source and a 40 millicurie Americium-241 source. The device had mistakenly been left on the tailgate of the technician's pickup truck when he left a jobsite to go to another work location. When the driver was stopped at an intersection, he saw in his rearview mirror that
the tailgate was open and stopped to verify the contents of the truck. At that point, he realized the gauge was missing. The technician had travelled approximately 13 miles before discovering that the device had been lost.

"The gauge was recovered later that same day (6/29/23) with no apparent damage."

Ohio Incident Number: OH230007


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

AGREEMENT STATE REPORT - DAMAGED GAUGE

The following information is a summary provided by the Oregon Health Authority via phone and email:

On July 7, 2023, at 0140 PDT, a Troxler moisture density gauge (Model: 3411-B, Serial: 10464, 40 mCi Am/Be, 8.1 mCi Cs-137) was damaged by a construction vehicle. The source rod was bent, and the source locking mechanism was damaged. Central Geotechnical Services, LLC. (the licensee) reported no public exposure or contamination after a site survey. The damaged device was transported and secured at the licensee's office. The device will be leak tested and returned to the manufacturer.

Oregon incident number: 2023-1659

ECCS POTENTIALLY INOPERABLE

The following information was provided by the licensee via email:

"At 0449 [EDT] on 7/12/2023, Millstone Unit 3 declared the 'B' train of the emergency core cooling system (ECCS) inoperable due to a degraded damper associated with the ventilation support system for the 'B' charging pump. At the time of this event, the 'A' train of service water was already inoperable due to planned maintenance on a breaker that would have prevented an 'A' service water valve powered from this breaker from closing on a safety signal. This configuration resulted in the possibility that the 'A' train of ECCS would not have been available to fulfill its design function under all postulated accident conditions. This event is being reported under 10 CFR 50.72(b)(3)(v)(B), '[any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to: (B) remove residual heat].'

"Subsequently, the 'A' train of service water was restored to operable at 0548 on 7/12/2023. Repairs and investigation continue on the 'B' train ECCS damper. The NRC resident has been notified. This event did not impact Millstone Unit 2. There was no impact to the public."