BOISE, Idaho — A lengthy project to excavate and remove radioactive and hazardous waste buried for decades at a nuclear facility sitting atop a vast aquifer in eastern Idaho is nearly over, US officials said.
The US Department of Energy said last week that it had removed the final volume of specially targeted buried waste from a 97-acre (39-hectare) landfill at its 890-square-mile (2,300-square-kilometer) site that includes Idaho. Includes National Laboratory.
Targeted radioactive waste included plutonium-contaminated filters, graphite molds, sludge containing solvents, and oxidized uranium generated during nuclear weapons production work at the Rocky Flats plant in Colorado. There are some radioactive and hazardous residues in the Idaho landfill that will receive soil cover.
Rocky Flats waste was packed in storage drums and boxes from 1954 to 1970 before being shipped to the Sagebrush Steppe, the high-desert of eastern Idaho, where it was buried in undamaged pits and trenches. The area is located approximately 50 miles (80 kilometers) west of downtown Idaho Falls.
The cleanup project, which began in 2005, is named the Accelerated Recovery Project and is one of about a dozen cleanup efforts at the Department of Energy’s site for nuclear waste that is finished or ongoing.
The project involving the landfill is part of a 2008 agreement between the Department of Energy and state officials, which required the department to excavate and remove specific types and amounts of radioactive and hazardous materials.
The agency said it removed about 13,500 cubic yards (10,300 cubic meters) of material – the equivalent of about 50,000 storage drums that hold 55 gallons (208 liters) each.
Most of the waste is being sent to the US government’s Waste Isolation Pilot Plant in New Mexico for permanent disposal. Some of the waste will be sent to other off-site repositories which may be commercial or Department of Energy sites.
The Energy Department said it is 18 months ahead of schedule in cleaning up the landfill.
“Burying waste was the primary concern of our stakeholders since the start of the cleanup program,” Connie Flohr, manager of the Idaho Cleanup Project for the Department of Energy’s Office of Environmental Management, said in a statement. “Completing the excavation early will allow us to get an earlier start on building the final cover.”
Republican U.S. Representative Mike Simpson represents an area that benefits from millions of federal dollars brought to the state by research work conducted at the Idaho National Laboratory.
“What exciting news for DOE and the Idaho Cleanup Project,” he said of the landfill work on Twitter. “A successful cleanup means protecting the area and the Snake River Plain Aquifer.”
The Eastern Snake River Plain aquifer the size of Lake Erie supplies farms and cities in the region. A 2020 US Geological Survey report states that radioactive and chemical contamination in the aquifer has been low or stable in recent years. This was attributed to a reduction in radioactive decay, changes in waste-disposal methods, cleanup efforts, and dilution from the water coming into the aquifer.
The report said contamination levels are below acceptable standards for drinking water set by the US Environmental Protection Agency, except for some in about 180 wells.
According to a US Geological Survey report, the nuclear site began operating in the late 1940s under the Atomic Energy Commission, a precursor to the Department of Energy, and contamination of the aquifer began in 1952.
Pollution reached the aquifer through injection wells, unlined seepage ponds, pits into which radioactive material was dumped from other states, and mainly through accidental spills during the Cold War, before regulations to protect the environment were introduced. was implemented.
A US Geological Survey report states that tritium is responsible for most of the radioactivity in the water released into the aquifer, but also includes strontium-90, cesium-137, iodine-129, plutonium isotopes, uranium isotopes, neptunium-237, americium- 241 is also included. and Technetium-99.
In 1989, the area became a Superfund site when it was added to the National Priority List for Uncontrolled Hazardous Waste Sites.
A series of lawsuits between the state and federal government in the 1990s led to a 1995 agreement that the Department of Energy shipped nuclear waste to Idaho.
The agreement was seen as a way to prevent the state from becoming a high-level nuclear waste stockpile. It also requires cleanup and removal of existing nuclear waste, which is ongoing.