The following information was obtained from the State of
California via email:
On December 10, 2014, the Assistant Radiation Safety Officer of Koury Geotechnical Services contacted the Radiologic Health Branch Brea office regarding a moisture density gauge that was run over by a construction vehicle at a construction site at 6500 Atlantic Avenue in Long Beach. The gauge was a CPN Model MC1-DRP gauge, S/N MD30901675 (10 mCi Cs-137, 50 mCi Am:Be-241). The gauge was in use as the Cs-137 source was extended approximately 8 inches in the soil at the time of the incident. The source rod has been damaged. The electrical body was also damaged but there was no evidence that the protective shield or the Am:Be-241source was damaged. The Long Beach Fire Department was notified and responded to the incident. Fire Department personnel did a visual inspection and radiation survey of the area and noted that the area was secured at least 50 feet from the gauge and noted that the dose rates at this boundary were at background. Long Beach Hazmat then arrived to take control of the area from the Fire Department. After assessing the situation they contacted Los Angeles County Radiation Management to assist in placing the sources in a safe condition. Thomas Gray and Associates (California materials license number 2105) was also contacted to assist in remediating the damaged gauge. The Health Physicist from Los Angeles County, with assistance from the Thomas Gray technician, was able to place the Cs-137 source into the shielded position and verified that the shutter block was in the proper position. A visual inspection of the body was performed and indicated that there was no damage to the shielding. Wipes were taken on the body of the gauge then tested using a survey meter with a geiger-mueller pancake probe. The wipes were at background indicating that the sources were not leaking. An MCA [multi-channel analyzer] was used to verify that both the Cs-137 and AmBe-241 sources were present. The gauge body was placed in the transport case along with the rest of the gauge parts then turned over to the Koury technician to take to Maurer Technical Services (California radioactive license 6163) to be shipped to the manufacturer so that it can be repaired or the sources recycled.
The investigation is on-going and any citations will be determined at a later date.
CA Report No.: 5010-121014