The following information was provided by the
California Department of Public Health via email:
On May 15, 2025, the radiation safety officer (RSO) of Alta California Geotechnical, Inc. (Alta), contacted the Brea office of the California Department of Public Health to report a stolen moisture density gauge. The gauge was a CPN model MC-3 S/N MD30907144 (10 mCi, Cs-137; 50 mCi, Am:Be-241). The gauge operator discovered the gauge was missing on May 14, 2025, at approximately 1500 PDT, before they left the jobsite in Murrieta, CA. The operator noticed that the tailgate on the truck was down, the gauge case was open, and the gauge was missing. Alta personnel searched the surrounding area without locating the gauge and contacted the Murrieta Police Department to report the theft. A second search was performed the following morning with no success locating the gauge. The event was reported to the California Department of Public Health. The RSO confirmed that a trigger lock, securing the Cs-137 source in the shielded position on the gauge, was in place. The licensee's investigation into this event is ongoing and will be reviewed further by the California Department of Public Health.
California 5010 Number: 051525
- * * UPDATE ON 05/16/25 AT 1934 EDT FROM DONALD OESTERLE TO KERBY SCALES * * *
The following update was received from the California Department of Public Health via email:
On May 16, 2025, the gauge was found and recovered. The gauge will be sent to the service provider to be evaluated.
Notified R4DO (Gepford), NMSS_Events_Notification, ILTAB, and CNSNS Mexico via email.
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