Four workers at the Hanford Site received medical attention Thursday after being exposed to toxic vapors, according to workers with knowledge of two separate incidents.
The first exposure happened around 10:30 a.m. The workers affected were two pipefitters, a millwright and a safety officer. Three of the four were evaluated by medical professionals.
The second occurred in an instrument technician shop near the AW farm around 3:00 pm. Seven people smelled odors there, but only one elected to receive medical evaluation at the onsite clinic.
Since March, 56 separate incidents have occurred where workers received medical care after reporting a vapor exposure. In nearly all cases, the workers were evaluated at the on-site medical clinic and cleared to return to duty.
Several workers who breathed in toxic vapors this year were transported to a nearby medical care for treatment. They say they continue to experience medical problems months after their exposure.
The Hanford Site holds millions of gallons of toxic sludge in large underground tanks. Government studies have found nearly 2,000 toxic chemicals inside the tanks -- the leftovers from the messy work of plutonium production during the Second World War and the Cold War. Caustic chemicals were used to melt uranium fuel rods from nuclear reactors at the site, then small amounts of plutonium were removed from the dissolved fuel.
Waste from the process was pumped into 177 tanks. Decades later, it remains deadly and will continue to be until the technology is developed to permanently dispose of it. The waste, hot from radioactive decay, vents toxic vapors at irregular intervals. While special filters keep radiation from escaping from the tanks, the toxic gases pass through unstopped into the atmosphere around the tank farms.
The KING 5 Investigators reported on Monday that the company that manages the tank farms issued an order recently escalating safety precautions in the Hanford tank farms. Washington River Protection Solutions ordered workers to use respirators every time they work in the portions of the site where single-shell waste tanks are located. Prior to that change, workers could opt out of wearing respirators in many parts of the tank farms.
WRPS said the order was based on feedback from a panel of experts convened earlier this year to study the string of vapor exposures. While that panel's report has not been released, the company said it did not want better safety practices to have to wait for the panel's report.
WRPS issued the following statement Thursday afternoon:
Two Washington River Protection Solutions (WRPS) employees were evaluated by the Hanford Site medical provider earlier today for potential vapors-related symptoms and released back to work. One was working today near a facility in the proximity of two tank farms. The other worker smelled odors yesterday near C Farm, experienced overnight symptoms, but did not report them until today.
In addition, two other WRPS workers and another Hanford employee—who had reported no symptoms—were taken for precautionary medical evaluation related to today's event and released back to work.
KING 5's Russ Walker contributed.