The following information was provided by the
Illinois Emergency Management Agency (the Agency) via email and phone:
On August 1, 2024, the Agency was advised by the radiation safety officer (RSO) for Eastern Illinois University that twelve strontium-90 button sources were missing from inventory. As the sources had been secured in a locked cabinet, they were likely mistakenly included in a low-level radioactive waste pickup that occurred on July 8, 2024. The RSO was not present for the shipment, nor was the waste pickup coordinated with relevant radiation safety program staff. The sources were identified as missing when the RSO did a sealed source inventory on August 1, 2024. The sources were not itemized on the waste manifest and while this is the most likely disposition, it cannot be verified at this time.
The twelve sources were 0.5 microcurie Sr-90 button sources when assayed in 1970. All were manufactured by The Nucleus, Inc. as model Sr-90-S-5, with serial numbers 6/2/70-1 through 6/2/70-12. They are now decayed to approximately 0.14 microcuries each and do not represent a radiation safety concern. The Agency has already conducted a reactive inspection. The licensee is assessing the availability of documentation through the waste broker (NAC Philotechnics). Pending that documentation and a response to the Notice of Violation, this matter is considered closed.
Illinois item number: IL240018
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