The watchdog organization Hanford Challenge says it found traces of radioactive americium in the engine filters of two employee vehicles that had been parked at the Hanford Site’s Plutonium Finishing Plant. The vehicles had previously been checked at Hanford and declared clean in the wake of a radioactive contamination spread from the plant demolition site, according to the group.
Four workers volunteered to have their vehicles checked, and Hanford Challenge collected five filters from them when the vehicles were off Hanford in the nearby Tri-Cities in central Washington state. Marco Kaltofen, president of Boston Chemical Data Corp. and an affiliate research engineer at Worcester Polytechnic Institute, was in charge of the analysis.
“The fact that vehicles were checked and released to these workers, only to find that they were still contaminated, raises disturbing questions about the credibility of Hanford’s program,” said Tom Carpenter, Hanford Challenge executive director, in a press release. The group plans surveys of filters from other employee vehicles.
The Department of Energy said it was not been given the opportunity to split samples and arrange for its own analysis of the filters.
Contamination was found at levels likely below what could be detected with handheld equipment used to survey vehicles for radiation at Hanford. The sample with the most contamination was measured at 0.9 picocuries per gram of material. The Energy Department said Tuesday that its “survey equipment and processes are designed to detect contamination levels well below regulatory and worker-protection requirements.”
In response to Hanford Challenge’s discovery, a Hanford employee issued a stop work order on Tuesday until the government vehicles being used at the Plutonium Finishing Plant demolition were checked for radioactive contamination.
By 2 p.m. Tuesday, the interiors of 23 of 44 government vehicles had been surveyed, with no radioactive contamination found, according to DOE. The engine or cabin air filters of three vehicles that had been found to have the greatest exterior contamination since December were checked, with no contamination found, it said. Since December, surveys have found 29 government and seven worker vehicles to be contaminated.