Updated: 10/30/2014 2:52 PM KSTP.com
(AP) SPOKANE, Wash. - SPOKANE, Wash. (AP) â€” The U.S. Department of Energy does not have an adequate system to detect whether harmful vapors are sickening workers at the Hanford Nuclear Reservation, the nation's most polluted nuclear site, according to a new report issued Thursday.
Dozens of workers in the past year have reported smelling vapors and then becoming ill after working around some of the 177 underground nuclear waste storage tanks at Hanford. The waste is a byproduct of the Cold War-era production of plutonium for nuclear weapons.
The workers were checked by doctors and cleared to return to work.
But the new report concludes that the methods used to study the vapor releases were inadequate, and did not account for short but intense releases of vapors from the tanks.
"Vapors coming out of tanks in high concentration plumes sporadically intersected with the breathing zones of workers, resulting in brief but intense exposures to some workers," said the report prepared by a team of experts led by the DOE's Savannah River National Laboratory.
Computer modeling showed that under certain weather conditions, high concentrations of vapors could exist 10 feet downwind from the release point and "potentially in workers' breathing zones," the report said.
The report said evidence "strongly suggests a causal link between chemical vapor releases and subsequent health effects, particularly upper respiratory irritation, experienced by tank farm workers."
Hanford, located near Richland, for decades made plutonium for nuclear weapons, including the bomb dropped on Nagasaki, Japan. Some 53 million gallons of the most highly radioactive and toxic wastes are stored in the underground tanks. Cleanup of the site costs some $2 billion per year and the work is expected to take decades.
The Department of Energy has said monitors worn by tank workers have found no samples with chemicals close to the federal limit for occupational exposure. An analysis of 3,200 samples collected by monitors worn by workers found just 19 that showed chemicals present at more than 1 percent of the occupational exposure limit, the agency said recently.
The Department of Energy said in a press release that the report "provides additional insight and recommendations on how to build on the steps that have already been taken to reduce vapor exposures in the tank farms."
"The report also identifies several areas where additional research is needed to better understand and further reduce vapor exposures," the Energy Department said.
Washington River Protection Solutions, the contractor cleaning up the underground tanks for the Energy Department, said the company had already started making changes based on drafts of the new report and believes its recommendations will make the site even safer.
The watchdog group Hanford Challenge wondered if workers were being protected now.
"The current number of workers sent for evaluation has risen to over 56 since March 2014", said Tom Carpenter, director of Hanford Challenge.
"Hanford management has responded to the toxic vapor exposures by claiming in July that there were no vapor exposures," he said. "Hanford's program falls far short of where it needs to be in order to protect workers, or even detect vapor exposures at all."
A 10-member team of experts was formed in June at the request of WRPS to study the vapor releases.
The report contained 10 overarching recommendations and more than 40 supporting recommendations. They include proactively sampling the air inside tanks to determine its chemical makeup; accelerating new practices to prevent worker exposures; modifying medical evaluations to reflect how workers are exposed to vapors and accelerating improvements to detect and control vapor emissions.
(Copyright 2014 by The Associated Press. All Rights Reserved.)