A small amount of radioactive contamination has been found in the air filters of two vehicles parked at the Plutonium Finishing Plant at the Hanford nuclear reservation, according to a Seattle-based Hanford watchdog group.
Hanford Challenge took five filters from four vehicles in Richland and Pasco that Hanford workers parked at the plant. The cars previously were checked at Hanford and declared clean of contamination, according to Hanford Challenge.
The filters included a mix of cabin and engine filters, with the contamination found in two of the engine filters.
In response, an employee issued a stop-work order Tuesday on the use of government vehicles at the plant until more checks for radioactive contamination could be done. Any worker who believes conditions are unsafe can halt work.
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The filters collected off Hanford were sent to Marco Kaltofen, who is president of Boston Chemical Data Corp. and an affiliated research engineer at Worcester Polytechnic Institute’s Nuclear Science and Engineering Program in Massachusetts, for analysis for radioactive contamination.
These vehicles were used by their families, to carry groceries and to go to and from work.
Tom Carpenter, Hanford Challenge executive director
They contained americium, a radioactive material associated with the past production of plutonium at Hanford for the nation’s nuclear weapons program, according to the analysis.
Americium also is used in home smoke detectors, with a smoke detector containing up to about about 1 million picocuries of americium, according to the Nuclear Regulatory Commission.
The amount measured per gram of material tested from worker cars was about 1 picocurie.
However, the americium in smoke detectors is contained in ceramic and foil to prevent it from becoming airborne like the contamination at the Plutonium Finishing Plant, and the Environmental Protection Agency warns against tampering with it.
The bottom line is that Hanford officials should be controlling plutonium and americium, and americium should not be found in worker cars, said Tom Carpenter, Hanford Challenge executive director.
“The owners of these vehicles are devastated and scared about the heath of their families,” he said. “These vehicles were used by their families, to carry groceries and to go to and from work.”
Carpenter had expected that no contamination would be found, considering the filters from just four cars were checked. But after finding two of four cars with contamination, Hanford Challenge and Kaltofen are checking filters from more vehicles.
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.
Tom Carpenter, Hanford Challenge executive director
After a spread of radioactive contamination was discovered in mid December at the Plutonium Finishing Plant, the Department of Energy said seven cars employees had parked at the plant while they were working had specks of radioactive contamination.
The contamination was on the exterior of the vehicles. Hanford officials say the contamination was removed and workers were free to drive those and other cars home.
“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,” Carpenter said.
DOE said in its daily report Tuesday afternoon that filters in some private vehicles had been surveyed for radiation and found no contamination in the filters.
The checks would have been done with hand-held detection instruments that likely would not have found amounts as small as a single picocurie, which could be detected in a laboratory analysis.
Survey equipment and processes are designed to detect contamination at levels well below regulatory and worker-protection requirements, according to DOE.
Neither DOE nor its contractor were given the opportunity to split samples to allow Hanford officials to analyze them, the daily report said.
44 government cars in use at the Plutonium Finishing Plant
23 checked by Hanford crews and declared clean
The Washington State Department of Health received the information from Hanford Challenge and was evaluating the data, said John Martell, manager of the Radioactive Air Emissions Section of the department’s Office of Radiation Protection.
It has been doing its own monitoring for the spread of airborne contamination at Hanford, finding very low levels of contamination that might be linked to demolition of the plant miles away.
There have been no levels of radioactive contamination detected off Hanford by the Department of Health that indicate a risk to public health, according to department officials.
But the Department of Health continues to be concerned, Martell said. It sent a letter to the Department of Energy late in January formally listing its concerns and asking for more information.
Finding some contamination in vehicle air filters is not entirely surprising, given that the Department of Health has found contamination in the air at Hanford where the cars would have driven, Martell said.
Tuesday, Hanford crews were surveying the 44 government vehicles used at the Plutonium Finishing Plant in response to the stop-work order.
Plant workers are using offices and parking lots well away from the plant and are shuttled to the plant in government vehicles, as needed, as part of the response to the radioactive contamination spread.
As of 2 p.m. Tuesday, crews had surveyed inside 23 of the government vehicles, finding no contamination.
The filters of two government and one private vehicle that had the greatest exterior contamination after the December contamination spread was discovered have been checked for contamination, with none found, according to DOE.
After an airborne spread of contamination in July at the Plutonium Finishing Plant, 31 workers tested positive for inhaling or ingesting contamination.
Since mid-December 282 central Hanford workers have requested checks for internal contamination.
With some results still pending, 229 workers have been found to have no contamination. Eight workers have small amounts of contamination, with the highest verified dose of radiation from contamination within their body figured at up to 10 millirem per year over 50 years.
In comparison, the average U.S. resident is exposed to about 300 millirem a year from background and naturally occurring radiation.