Idaho waste site receives final shipment

28 May 2021

The largest waste disposal site at the US Department of Energy's Idaho National Laboratory (INL) has received its final shipment of radioactive waste, meaning work can now begin on the closure of the facility. Separately, the DOE Office of Environmental Management (EM) has announced the award of a USD6.4 billion cleanup contract for INL's site near Idaho Falls.

Crews prepare to place the final waste shipment into a vault at SDA (Image: DOE EM)

Personnel from INL site cleanup contractor Fluor Idaho used a 55-ton cask to insert activated metals into a concrete-lined vault within a fenced section of the 97-acre Subsurface Disposal Area (SDA).

The SDA began receiving waste generated at the INL site in 1952 and has been used for the disposal of low-level, hazardous and transuranic wastes in pits and trenches for more than 50 years. The site stopped receiving transuranic and hazardous wastes for disposal in 1970, but continued to receive boxed low-level radioactive waste and, more recently, highly radioactive metal debris, inside specially designed vaults.

SDA's first set of 100 concrete vaults was constructed in 1993, and began receiving waste shipments in 1994. A second set of 100 vaults received its first waste shipment in 2008. The vaults, which are constructed of concrete manhole sections resting on a base and capped with a concrete plug, are configured in honeycomb arrays and surrounded by soil for additional shielding and protection from earthquakes, with the void spaces between the vaults in each array are filled with sand.

Most of the transuranic waste buried in the SDA was generated during nuclear weapons production activities at the Rocky Flats Plant in Colorado and was packaged in drums and boxes prior to being shipped to Idaho. Work began in 2005 to remove certain "targeted" waste - plutonium-contaminated filters, graphite moulds, sludges containing solvents and oxidised depleted uranium - from pits at the SDA. The retrieved waste is packaged, certified for disposal, and will ultimately be shipped out of Idaho, according to Fluor Idaho.

Following closure of the SDA, activated metals will be disposed in a facility managed by INL contractor Battelle Energy Alliance, located near INL's Advanced Test Reactor Complex.

End State contract

EM yesterday announced the award of a contract worth up to about USD6.4 billion over ten years to the Idaho Environmental Coalition, LLC (IEC) of Tullahoma, Tennessee for cleanup work at the INL site.

The Idaho Cleanup Project End State contract will include operations of the Integrated Waste Treatment Unit; used nuclear fuel management, including US Nuclear Regulatory Commission-licensed for the Independent Spent Fuel Storage Installations located at the INL site and at Fort Saint Vrain near Platteville, Colorado; transuranic and low-level waste disposition and management; facility decontamination and decommissioning; environmental remediation activities; and facility infrastructure.

IEC's members are Jacobs Technology Inc and North Wind Portage. Its small business teaming subcontractors include Navarro Research and Engineering, Inc, Oak Ridge Technologies, LLC, and Spectra Tech, Inc.

Researched and written by World Nuclear News