The following information was obtained from the State of
California via email:
On December 21, 2015, [the] RSO of Standard Soil Geotech, Inc. contacted the Radiologic Health Branch (RHB), Brea Office, to report a gauge (CPN MC-3 S/N M39129253, 10 mCi Cs-137, 50 mCi Am:Be-241) had been run over at the Southern California Edison facility in Porter Ranch in a section that was undergoing construction. The RSO stated that [the] casing of the gauge was damaged by a bulldozer and the Cs-137 source was in the extended position. The RSO confirmed that construction personnel were told to leave the area where the incident occurred. The only path to the incident site was secured by a construction vehicle. The RSO then left his office to assess the scene. After arriving at the scene [at approximately] 7:45 p.m. [PST], the RSO [was] provided photographs that indicated the Am:Be-241 source had detached from the casing and the Cs-137 source appeared to be exposed and not able to be returned to the shielded position. The RSO was asked if he had contacted the fire department and they confirmed that he had not. The RSO was informed that an RHB inspector would go to the scene and assist in removing the radioactive sources from the site.
After the RHB inspector arrived at the site [at approximately] 10:15 p.m., the damage to the gauge was assessed and it was determined that the Am:Be-241 source was not damaged but was detached from the gauge body. The Cs-137 source was also intact, but was still in the extended positon with the opposite end of the source rod broken off at top of the shield, preventing the source from being retracted into the shielded position. After the two parts containing the sources were moved away from the rest of the gauge parts, a survey was performed, using a Victoreen 451B-DE-SI. The dose rate of the remaining parts was found to be background (0.01 mR/hr) and the parts were placed in a plastic bag and removed from the site. The two sources were then placed in the transportation case and a small lead pig was taped to the Cs-137 source to reduce the radiation levels. The box was then closed and locked. A survey of the transport case found the highest dose on contact was 17 mR/hr. The gauge was then secured in [the RSO's] vehicle. Due to the damage to the gauge and the dose rates approaching the maximum allowable for a Type A package, DOT Special Permit 110646, CA-CA-15-99 was issued to allow the RSO to transport the gauge to secure storage at the Standard Soil Geotechnical facility until disposal can be arranged.
California Report No.: 5010-122115