While Washington River Protection Solutions did computer-model testing on the possibility of a liquid acetonitrile leak during the pre-treatment process, it did not calculate for the possibility of acetonitrile vapors, according to the internal DOE memo.
“WRPS designers stated they performed modeling to observe the effects of a hypothetical spill from the condensate tank but did not perform any modeling or calculations to determine the effect of a vapor leak,” the internal DOE memo said.
The memo said the acetonitrile vapor concentrations could reach from 49,910 parts per million up to 463,343 parts per million at different parts of the pre-processing facility.
The US Environmental Protection Agency and the Centers for Disease Control and Prevention both put the safety threshold for acetonitrile vapors at 170 parts per million. The federal Occupational Safety and Health Administration has a maximum permissible exposure limit of 40 parts per million, while the American Conference of Governmental Industrial Hygienists has set a threshold of 20 parts per million for acetonitrile vapors, the DOE memo said.
“This is really toxic stuff. (Acetonitrile) is known to be dangerous in fairly small amounts. … If this gas in concentrations would escape, it would affect nearby workers,” said Tom Carpenter, who stepped down April 1 as executive director of Hanford Challenge.
Carpenter noted that the secondary wastes — which could contain acetonitrile in the materials — would be trucked at least 12 miles from central Hanford to a facility in northern Richland to be mixed with a cement-like substance known as grout. He said the facility — owned and operated by Perma-Fix — is located within five miles of an estimated 30,000 Tri-Citians. That includes the huge Pacific Northwest National Laboratory less than a mile away, a high school and Washington State University’s Tri-Cities campus a couple miles away, and a significant number of homes.
Perma-Fix treats low-level radioactive and mixed chemical-radioactive wastes from across the nation.
In March, the Washington Department of Ecology sent a series of questions and comments to DOE about various aspects of the DFLAW project, including several questions about the concerns over significant amounts of acetonitrile vapors wafting into the air. So far, DOE has not responded to those questions, said ecology department spokesman Ryan Miller.
“No one mentions this document. No one mentions the worker exposure issues. … As far as I’m concerned, DOE hid this document (the August 2021 memo) from disclosure,” Carpenter said.
Meanwhile, Carpenter also criticized Perma-Fix’s safety record, specifically pointing to two on-site fires involving hazardous materials in 2019. In 2020, Hanford Challenge published a critical report of Perma-Fix’s safety records in the 21st century, of which the two 2019 fires were the most recent incidents.
Citing information made to state and federal agencies, the Hanford Challenge report said one of the fires happened at Perma-Fix when some hot glassified radioactive material from Chicago ended up on a wood pallet, which caught fire.
Hanford Challenge quoted a Washington Ecology Department report that said: “The fire at Perma-Fix Northwest could have been catastrophic, as the fire alarms were not working, and hourly fire inspections (in place of the fire alarms) were not being performed when the fire happened.” Additionally, Perma-Fix stated there are no fire sprinkler systems installed at the facility due to potential radiological contamination issues.
Then in December 2019, Perma-Fix notified the EPA that its staff found and extinguished a small fire inside a metal box of low-level, non-hazardous depleted uranium waste from a national laboratory near San Francisco. Hanford Challenge quoted DOE research that: “Solid uranium, either as chips or dust, is a very dangerous fire hazard.”
Carpenter also criticized the DOE for not having a plan for disposing of grouted secondary waste produced by Perma-Fix. “They don’t have a disposal pathway for acetonitrile,” he said.
Perma-Fix spokesman David Waldman responded to emailed questions to the company, saying “Currently, we do not have a request to treat the waste you mentioned, so we cannot comment any further.”
Waldman wrote: “The fires you mentioned were very minor incidents. The fires were managed by our own staff and fully disclosed to our regulators, as required. We had no injuries to our employees; no escape from hazardous materials; no damage to the building; and our fully trained and experienced staff professionally managed the situation. The Richland fire department responded only as a precaution to one of the fires, but just to confirm that everything was under control.”