Construction on the 53,000-square-foot Integrated Waste Treatment Unit started in 2007.

The company in charge of cleanup at the U.S. Department of Energy desert site west of Idaho Falls reported some progress over the past year, one notable upcoming milestone being that the Integrated Waste Treatment Unit could finally start processing sodium-bearing waste next summer.  

While there is still plenty of work left to be done, the end is at least somewhat in sight for the Idaho Cleanup Project's mission of processing the waste from Cold War-era nuclear weapons production buried in Idaho and shipping it out-of-state. About a year ago, closure work started on the site's Advanced Mixed Waste Treatment Project facility.

"It is now essentially empty and we have been removing the equipment (and) cleaning the inside of the building up," said Fred Hughes, president of cleanup contractor Fluor Idaho. "We're getting ready to characterize the asphalt pad and the internal walls of the structure, and that's all in preparation for completing the regulatory closure of the building and getting it ready for demolition."

Hughes said Fluor sent 106 shipments of transuranic waste to the Waste Isolation Pilot Project in Carlsbad, N.M. over the last year, making them responsible for about 62% of the shipments to WIPP. As for the Accelerated Retrieval Project V building, where four drums of radioactive waste exploded in 2018, Hughes said they have finished cleaning up the material that spilled during that event and recently got regulatory approval to close the building.

"It is now closed and sitting there ready for demolition," he said.

Hughes said .34 acres of transuranic and hazardous waste still need to be exhumed out of the ARP IX site, out of an original 5.69. This is expected to be done sometime in 2021. 

"We will finish up that project also next year, and then the plan is (for) the regulatory closure of all the ARP structures, decommission and dismantle them, and then, ultimately, there will be a 150-acre cap placed over that … part of the (Radioactive Waste Management Complex) facility," Hughes said. "It's basically an engineered earthen cover."

Even after the waste is removed, it will still take some time before the buildings can be knocked down and the cap put over the desert site. The amount of time the closures will take under the federal Resource Conservation and Recovery Act will vary but will take a couple of years in some cases. Once all the buildings are closed and torn down, the site will be covered with a cap designed to blend in with the surrounding desert while keeping rain and snow from passing through the remaining waste and into the East Snake Plain Aquifer beneath it. DOE's goal, Hughes said, is to have all of the structures gone and the cap installed somewhere in the 2031 to 2035 timeframe.

Among the remaining waste at the site are 900,000 gallons of liquid radioactive waste that is slated to be treated at the Integrated Waste Treatment Unit facility. Treatment of this has been delayed for years due to technical problems, leading DOE to miss deadlines in the settlement agreement and prompting Attorney General Lawrence Wasden to block shipments of spent nuclear fuel for research at Idaho National Laboratory. A year ago the state and federal government reached a deal where INL could receive some spent research fuel if certain milestones at IWTU were met, but this hasn't happened yet.

While it had been hoped that this would start this year, next year now looks more likely. Hughes said workers have been making modifications to the plant to prepare it for radiological operations. They are wrapping up installation of a decontamination system and adding some decontamination controls, including two robots that can remotely detect contamination and clean the waste storage canisters that are being tested right now. And, he said, they are wrapping up some modifications to fix a problem they had during the last couple of simulant runs when the gas filters kept getting clogged.

Hughes said the plan is to go through a readiness review of the plant with DOE early next year, and likely starting in the spring start a 50-day confirmatory simulant run to make sure everything works. He said the IWTU will likely start to process sodium-bearing waste in summer 2021.

Other than the IWTU, Hughes said Fluor is working on two other major projects at the Idaho Nuclear Technology and Engineering Center. One is the ongoing transfer of spent fuel from various areas of the site from wet to dry storage. The other is working on the 4,400 cubic meters of calcine, a granulated high-level radioactive waste that is currently stored in bins, that needs to be processed and ready to leave the state by 2035 per the 1995 Settlement Agreement. Hughes said Fluor is developing robots to enter the bins and transfer the waste to another bin set to process and repackage it, after which the emptied bins would be closed. He said he expects this work to get going in a year to 18 months.

When COVID-19 first struck in March, the Idaho Cleanup Project went down "minimum essential operations," Hughes said, which meant having about 300 employees on-site. Workers have been returning say May, and while there have been interruptions since then as employees who shows symptoms need to quarantine, Hughes said about three-quarters of the staff is back at the site now.

"We're making great progress," he said. "We're keeping the employees safe. In fact, they feel (safer than) working from home."

Reporter Nathan Brown can be reached at 208-542-6757. Follow him on Twitter: @NateBrownNews.