The Department of Energy’s fiscal 2023 budget request for nuclear cleanup at the Idaho National Laboratory includes $10 million toward early planning for  treatment and disposal of 1.2 million gallons of high-level radioactive calcine waste.

Under the 1995 Idaho Settlement Agreement governing disposal of spent fuel, DOE has until Dec. 31, 2035 to treat the 1.2 million gallons or 4,400 cubic meters of calcine and prepare it to leave the state, according to last week’s detailed budget justification for the DOE Office of Environmental Management (EM).

The agency’s fiscal 2023 budget request shows DOE has little margin for error to hit the 2035 milestone. No hard timetable dates have been identified, detailed cost estimates are not available yet and Critical Decision 4, which marks the end of construction and the nominal start of operations, is not expected until fiscal 2036. All this before the agency has established even preliminary cost ranges at Critical Decision 1.

The $10 million requested “includes the design portion” to assist the agency on Critical Decision 1 for identifying a preferred treatment and disposal alternative for the calcine located at the Idaho Nuclear Technology and Engineering Center. The granular-solid calcine is stored in six bins that lie over the Snake River Plain Aquifer.

The calcine waste is a byproduct left over from spent fuel reprocessing at the Idaho site from 1953 to 2000. Liquid waste from the reprocessing was dried into a granular substance now stored inside the reinforced concrete bins.  

A September 2019 report from the Government Accountability Office (GAO), said EM was “deferring further development of its plans to treat the calcine waste” after facing “challenges” in retrofitting the Integrated Waste Treatment Unit for that purpose. The treatment unit is designed to convert about 900,000 gallons of liquid waste into a granular form. While the cleanup office is encouraged by testing options for removing the waste from its storage bins, it lacks “a strategy or timeline,” for the project, GAO said in 2019.

DOE issued its Calcine Treatment Record of Decision in 2009 that selected hot isostatic pressing as the preferred option, according to the budget document. The process involves applying high heat and pressurized gasses inside a vessel to produce a ceramic waste form.

But DOE has done two analyzes of alternatives since then, one in 2016 and another in 2020, and plans a National Environmental Policy Act supplement analysis to support a revised Record of Decision for vitrification or direct disposal, according to the budget document.