Brookhaven lab tightens rules after leak

Brookhaven National Laboratory has adopted more rigorous safety standards following a September accident in which a leaking container exposed two technicians to low levels of radiation.

The lab's investigation determined that the Sept. 28 leak stemmed from a "misinterpretation" of controls governing the use, movement and packaging of sealed radioactive sources, the lab said in a statement Friday.

Officials said the accident occurred as the technicians were checking radiation detectors.

A lead container holding a brass rod in which radioactive cesium-137 was stored tipped over in a pickup truck. The workers "unknowingly tracked some of this material through a parking lot into their building, and one of those workers also tracked some of the material into another employee's personal vehicle," the lab said in its statement.

The internal review said all traces of radioactivity were cleaned up and there was no evidence of significant radiation exposure or environmental impact.

Completed within a week, the review involved more than 400 lab employees, the statement said.

The investigation determined there was a "structural failure" of the brass rod that contained the cesium-137. The cause of the failure is being studied.

The review also noted that although the lab had adequate standards for employees to safely move radioactive materials by vehicles, the employees in this case didn't think the standards applied to "sealed sources."

George Goode, assistant lab director for environment, safety and health, said sealed sources are considered to be safer because they are manufactured to contain radioactive material.

The lab said it has adopted more rigorous standards for handling sealed radiation sources. Training for employees has been updated.

In addition, cobalt-60 will replace cesium-137 as the substance used in calibrating radiation detectors because it is housed in a solid piece of metal, the lab said.