Final test run begins on Idaho’s IWTU after supply chain delays

February 25, 2022, 7:13AMRadwaste Solutions
The IWTU liquid nitrogen storage system at the DOE’s Idaho National Laboratory Site. (Photo: DOE)

The Department of Energy’s Office of Environmental Management (EM) stated on February 22 that its Idaho National Laboratory Site contractor is operating the final test run of the Integrated Waste Treatment Unit (IWTU), running waste simulant through the facility to ensure the plant’s performance and personnel proficiency for upcoming radiological operations.

The contractor, Idaho Environmental Coalition (IEC), was forced to temporarily shut down the IWTU and suspend its readiness assessment of the plant in January due to delays in shipping nitrogen to the site. According to a report by the Defense Nuclear Facilities Safety Board, the delays were caused by a shortage of truck drivers available to transport liquid nitrogen to the Idaho facility. Nitrogen gas is required during IWTU operations, and the facility must receive steady shipments as often as daily during the confirmatory run.

Next steps: In its announcement, EM said that IEC has begun a 50-day confirmatory run, during which it will assess the performance of new ceramic filters and other modifications while operating the IWTU under simulated radiological conditions. During the run, the independent contractor and federal assessment teams will evaluate the performance of the operating crews and the facility to prepare for radioactive waste processing.

Prior to the January shutdown, the IWTU had operated for eight continuous days and converted about 19,000 gallons of simulant into a granular solid. Since then, the IEC strengthened its agreement with its subcontractor to provide steady shipments of nitrogen, allowing crews to restart the plant and resume simulant treatment.

IEC, a joint venture led by Jacobs with North Wind Portage as a partner, was awarded a 10-year, $6.4 billion contract in 2021 to manage cleanup operations at the INL Site.

The process: The IWTU was constructed to treat approximately 900,000 gallons of sodium-bearing liquid waste, which was created during cleanout and decontamination activities following past spent nuclear fuel reprocessing operations at the INL Site. The plant uses steam-reforming technology to convert the liquid waste to a granular solid, which is transferred to stainless steel canisters and then stored in concrete vaults. Following the completion of waste treatment, the tank farm where the liquid waste is currently stored will be closed.

Processing 100 sodium-bearing waste containers through the IWTU is an EM priority for 2022.

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