Radioactive material that was removed from a shed behind a vacant San Carlos home and partially catalogued on May 3 has been identified, city officials said.
Test results indicated that it consisted mostly of Naturally Occurring Radioactive Material, or NORM, such as uranium ore samples, a radium clock, and other materials with thorium.
The home in the 1000 block of Cedar Street where the material was found was formerly occupied by Ronald Seefred, a retired scientist who had worked at the SLAC National Accelerator Laboratory in Menlo Park.
Seefred died in January at 82 years old. The radioactive material was discovered as the house was being prepared for sale, according to Redwood City Fire Chief Stan Maupin, whose department serves the city of San Carlos.
The materials, which were held in several small vials in small quantities, were transported to a lab in Richmond.
Ephrime Mekuria, associate health physicist at the California Department of Public Health, stated that a final report of the contents will still be developed.
Once the material was removed, workers with the San Mateo County Health Department performed two additional sweeps of the residence and did not find other radioactive sources. The residence was then turned back over to the property management company overseeing it.
A private firm will clean up any household hazardous waste, but there are no threats to the public at the property, city officials said.