Stolen Gauge Is Truly ‘Hot,’ Officials Warn

Investigators warned Thursday that equipment stolen from a construction site in Chino Hills contains a radioactive heavy metal.

Thieves broke into a storage container at a construction site for Standard Pacific Homes and took a generator and a device with a probe containing a metal core that emits radioactive gamma rays.

The probe uses the isotope cesium 137 to measure soil density to determine, for example, whether it can support a road or a building.

“We are trying to warn the public in case someone leaves this thing by the side of the road, and a youngster picks it up and tries to break it. They could be exposing themselves,” said Sgt. T.A. Peters of the San Bernardino County Sheriff’s Department.

The metal inside the device is highly radioactive, about 1,000 times more than materials typically used in college physics labs but 100 times less than what is used in medical applications, said Doug Carter, technical support manager for CPN International, which made the instrument.

Carter said that the cesium 137 is encased in stainless steel and that there is no record of any of his company’s devices rupturing or of someone releasing the cesium, even accidentally.

A person within about 4 inches of the cesium 137 in the device would be subject to a radiation dose equivalent to about two dental X-rays per hour, said Dan Peterson, professor of physics at Harvey Mudd College. “Not an insignificant amount,” Peterson said. The dose lessens dramatically as the distance increases, he said.

Because the probe contains radioactive material, operators are required to undergo special training and its owners need a license from the state. Stolen or lost equipment must be reported to state officials.

An official from GeoSoils, a Santa Ana company that owns the equipment, said it would cost $6,000 to replace the instrument. The probe was being used to study a hillside for grading.

The stolen generator is worth about $2,000.