The Nuclear Regulatory Commission held a public online meeting on June 26 to take comments on closure plans for the Calcined Solids Storage Facility at the Department of Energy’s Idaho National Laboratory.
“Calcine is a solid, granular waste form produced through the calcination of liquid radioactive waste resulting, in part, from spent nuclear fuel (SNF) reprocessing at the Idaho Nuclear Technology and Engineering Center (INTEC), on the Idaho National Laboratory site,” according to a DOE fact sheet.
There are roughly 1.16 million gallons or 4.400 cubic meters of granulated calcine stored in six silos or bin sets at INTEC. One additional bin set was built to store future calcined waste but was never placed in service; it remains empty, according to material posted online by DOE and NRC.
DOE has been looking at options for solidifying the calcine waste.
At the recent public meeting, NRC discussed responses to requests for additional information, according to an online slide presentation for the meeting.
While DOE determines whether waste is incidental to reprocessing at sites such as the Idaho lab’s tank farm facility, NRC is charged with providing technical advice and consultation on DOE’s assumptions and conclusions.
DOE submitted its Calcined Solids Storage Facilities waste determination in October 2023 while NRC issued requests for additional information in April 2024. The responses to the request for additional information came in March.
“NRC staff has sufficient information to complete its review,” according to the presentation. “NRC may perform additional independent modeling and analysis to risk-inform monitoring activities.”
Under a legal agreement between the federal government and the state, DOE must treat any high-level waste at Idaho National Laboratory and have it ready to be transported out of state by 2035. Spent fuel processing at INL ended in 1992.
A three-minute youtube video on the calcine cleanup at the Idaho lab is available online. There is currently a mock-up facility using a simulant to mimic calcine. The project is testing robotics and technology for extracting the calcine.
