Radiation source in stolen metal box sought

Tuesday, Feb. 2, 1999 | 1:55 a.m.

Federal and Nevada health officials are searching for a locked metal box containing two radioactive sources that was stolen from a Las Vegas engineering company.

The radioactive material is not considered a threat to health or safety as long as it remains in its protective lead-lined box, officials said.

A worker for the company, CTE Nevada, Inc., parked his pickup truck behind the firm's office at 4560 S. Valley View Blvd. on Jan. 26 about 5:30 p.m.

When he returned about an hour later, the box was gone. Chains holding it to the back of the truck had been cut.

CTE supervisors notified the Nuclear Regulatory Commission in Walnut Creek, Calif., and Metro Police about the stolen box, which could be yellow, orange or blue and displayed the three triangles warning of radiation inside the container.

CTE is licensed by the NRC to use the radioactive materials on job sites around the valley.

The Nevada Radiological Health Division also was notified.

The radioactive materials used by the engineers in a moisture density gauge to sample soils at construction sites have not been recovered late Monday.

The gauge, worth $7,000, uses cesium-137 and Americium-241 to measure how compact a construction site's soil is and to test its moisture content.

Cesium-137 has a radioactive half-life of 30 years, Americium-241 of 400 years. That means after the half-life time passes, half of the radiation remains active.

The radioactive sources, shielded by lead inside the 15-inch by 6-inch box, are about the size of a marble or pea. As long as they are contained in the box, there is no danger of radiation exposure, said Breck Henderson of the Nuclear Regulatory Commission office in Walnut Creek.

If someone sliced the box open with a hacksaw or took a sledge hammer to it and removed the radioactive materials, the person could be exposed to radiation. "Yes, you could get a pretty serious dose of radiation," Henderson said.

The box contains about 10 millicuries of cesium-137 and 40 millicuries of Americium-241. A millicurie is a measure of radioactive energy equal to one-thousandth of a curie.

The radiation sources cannot be used to make a nuclear weapon, Henderson said. It takes uranium-238 or plutonium-239 plus high explosives to create a device capable of a nuclear explosion, he said.

About 104 radioactive gauges disappear across the nation each year, Henderson said. "This stuff is at every construction site," he said. "Bulldozers run over them all the time."

As long as the lead shielding inside the box remains intact, there is no danger of exposure, even if the container is squashed flat.

All of the radiation experts said the best thing to do if someone finds the box is call authorities.

"We are ready to assist if it is found," said Stan Marshall, chief of the Nevada Radiological Health Division. Radiation experts can examine the box with monitors to make sure it is not leaking radiation, he said.

The Nevada Operations Office of the Department of Energy was not called to help find the material, DOE spokesman Derek Scammell said. "That's normally up to the state," he said.