The Department of Energy’s facility to treat sodium-bearing radioactive waste at the Idaho National Laboratory was taken offline again after getting 17 days into a scheduled 50-day demonstration intended to clear the way for radioactive operations.
The DOE and cleanup contractor Idaho Environmental Coalition decided to curtail operations of the Integrated Waste Treatment Unit (IWTU) on Saturday Feb. 26, a DOE spokesperson said in a Thursday email.
“While performing ongoing simulated waste operations, IWTU crews began to observe unexpected interactions between the plant off-gas filtration system and one of the main processing vessels, causing fluctuations in operating temperatures and gas concentrations,” the DOE spokesperson said.
After it was shut down, the plant was placed in a cool down phase that was expected to last about a week, the spokesperson said. That period would seemingly end this weekend.
The IWTU staff are analyzing potential causes based on data collected so far, the DOE spokesperson said, adding a “physical examination of the filter systems and processing vessel will be necessary to fully identify causes and actions necessary to resume operations.” That will occur following the cool down “when safe to do so,” the spokesperson said.
The plant has processed approximately 33,000 gallons of simulant during its approximately 17 days of operations as part of the scheduled 50-day demo run.
This event marks the second big disruption that lasted a week or more since the IWTU’s test run with simulant commenced in earnest on Dec. 27, days after workers discovered and corrected the backwards installation of a valve-position indicator. The test run was placed on hold between Jan. 6 and Feb. 17 while DOE and its Jacobs-led cleanup contractor at the laboratory lined up an adequate supply of nitrogen for the plant following disruptions of gas delivery from Utah.
The plant is meant to convert between 850,000 and 900,000 gallons of liquid, sodium-bearing waste at a laboratory complex tank farm into a granular substance that will be stored in steel canisters until final disposal. The liquid waste is left over from nuclear fuel reprocessing.
The IWTU, which has cost more than $1 billion to engineer and construct, has a long history of fits and starts. It was originally built by CH2M-WG Idaho — CH2M is now part of Jacobs — in 2012 but never worked as designed. The following contractor, Fluor Idaho, oversaw numerous engineering changes to the plant including the primary reaction vessel known as the Denitration Mineralization Reformer. Now the Idaho Environmental Coalition, a partnership of Jacobs, North Wind and various subcontractors, is in charge of the facility.
