The following information was provided by the
Texas Department of State Health Services (the Agency) via email:
On May 22, 2023, a general licensee notified the Agency that it had determined on May 9, 2023, that one of their Ronan RLL-1 gauges containing 0.9 millicuries of cesium-137 (10 sealed sources of 90 microcuries each), was lost. The general licensee reported the device had been removed from service February 2022 and placed in storage in a warehouse at one of its sites. A third party was hired for management and control of the warehouse.
By the end of May 2022, it was discovered the gauge was not in the warehouse. Believing it was still onsite, over the next 12 months the general licensee made repeated attempts, interviews with current and former staff, and more than eight thorough searches of the warehouse and it reached out to the supplier. It did locate the detector that went with the gauge but not the gauge itself. After reporting this to the Agency, the general licensee also rented radiation detectors and searched the warehouse and the area around it. The general licensee reported it believes the gauge is likely to still be at the plant site due to its size, weight, and labeling. Due to design and low activity, the general licensee does not believe any persons have been exposed to elevated radiation.
To prevent recurrence, the general licensee reviewed and revised its radiation protection manual and refresher training was presented to applicable plant employees. On a quarterly basis going forward, it will verify and document their general license radioactive sources and each of their locations.
Texas Incident Number: 10021
Texas NMED Number: TX230028
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