The following is a summary of a phone call with the licensee:
On April 25, 2019, the licensee was using a Troxler Model 3440 density gauge, serial number 24233, with (per Troxler literature) an 8 mCi Cs-137 and a 40 mCi Am-241/Be source, on a project. The technician using the gauge noted the gauge was giving different than expected readings and stopped using the gauge. The gauge was taken to a repair facility to be checked out. On May 21, 2019, the repair facility notified the licensee that the source was found to be missing on May 20, 2019, at approximately 1700 EDT.
The licensee has notified NRC Region 3 Inspector (Gattone), the State of Michigan, and the Berrin County Police. The licensee and Berrin County HazMat are trying to locate the source. Region 3 Inspector (Sulaiman) is headed to the site.
The NRC Region 3 Inspector (Gattone) requested that the licensee provide a certificate for the Cs-137 source that was lost. After receiving the certificate, it was determined that the current source activity is 4.5 mCi.
Notified R3DO (Cameron), ILTAB, NMSS Event Notification, CNSC, and NRC Region 3 Inspectors Gattone and Sulaiman via e-mail.
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