The Department of Energy said this week crews have fixed the cause of the recent leak at the Integrated Waste Treatment Unit at the Idaho National Laboratory and should start running the facility soon with a mixture of 90% simulant and 10% radioactive sodium-bearing waste.
Integrated Waste Treatment Unit (IWTU) crews on Tuesday “completed key corrective maintenance efforts in the lead-up to beginning radiological operations,” a DOE spokesperson said in an email late Wednesday. The federal agency and its contractor, the Jacobs-led Idaho Environmental Coalition, also figured out this month the wrong type of steel plugs were installed in a key area of the plant.
An earlier simulant leak was chalked up to installing the wrong type plug, according to DOE. Personnel at IWTU caught on to the mistake while evaluating the carbon steel plug that became corroded and fell out of a valve in the wet decontamination system, causing the leak.
“The design requirements for the valves mandated the manufacturer use stainless-steel plugs,” rather than carbon steel, the DOE spokesperson said in the email. All affected plugs “have been replaced with stainless steel versions.”
The last maintenance fix was completed Tuesday, the DOE spokesperson said. This week feed nozzles were replaced in the Denitration Mineralization Reformer (DMR), the spokesperson said in the email. The DMR is where superheated beads are coated with the radioactive waste as liquid waste is converted into a more stable granular form for eventual disposal.
Despite the latest glitch, DOE officials are hopeful the steam reforming technology plant, bedeviled by more than a decade of technical difficulties, is on the brink of solidifying its first canister of radioactive waste sometime next month.
The IWTU, designed to convert 900,000 gallons of liquid waste leftover from fuel reprocessing, was first constructed by a CH2M-led contractor but never worked as intended. After years of rework and re-engineering by subsequent contractor, Fluor Idaho, the Jacobs-led team became the latest contractor to take the reins in January 2022.
