IDAHO FALLS, Idaho – Closure of the Idaho National Laboratory (INL) Site’s largest building, which once housed 65,000 cubic meters of Cold War weapons waste, is underway and is scheduled for completion next year.
The Transuranic Storage Area Retrieval Enclosure at the Radioactive Waste Management Complex is large enough to house an aircraft carrier or four football fields.
It was constructed over an asphalt-lined waste storage area that accepted tens of thousands of drums and boxes of transuranic and hazardous waste from the former Rocky Flats Plant near Denver from 1970 to the late 1980s.
After that waste was stacked several rows deep, it was covered with clean soil. EM completed construction of the enclosure in 1996 after overcoming engineering challenges to erect the building without impacting the waste.
Crews with EM contractor Fluor Idaho have dismantled the building’s inner enclosures previously used to open drums and boxes of waste. Workers are currently clearing equipment as part of the closure process under federal and state regulations. Asphalt pads within the building will be taken out and disposed.
Crews retrieved the last of the waste from the storage area beneath the enclosure in early 2017. They’ve been characterizing, treating, repackaging, certifying, and shipping the material to EM’s Waste Isolation Pilot Plant for disposal.
The building’s asphalt will be disposed at the Idaho CERCLA Disposal Facility (ICDF) if sampling indicates the material meets the landfill’s waste acceptance criteria. The ICDF is a 510,000-cubic-yard lined landfill in the south-central portion of the INL Site used for cleanup waste generated throughout the 890-square-mile INL Site. CERCLA stands for the Comprehensive Environmental Response, Compensation, and Liability Act.
The enclosure is part of the larger Advanced Mixed Waste Treatment Project facility, which is scheduled for a phased closure. The first phase is closure and removal of the enclosure to make room for a drainage system that will channel water away from a 150-acre soil cover that will be constructed over the nearby Subsurface Disposal Area (SDA). That site accepted waste for shallow burial from 1952 to 1970.
Construction of the cover, or cap, will begin after workers at the Accelerated Retrieval Project IX complete targeted waste exhumation of the last of 5.69 acres of transuranic and hazardous waste. EM and Fluor Idaho expect to complete removal of the last 0.34 acres of waste in 2021.