Idaho Waste Treatment Facility Employs Successful Radiation Protection Program

Idaho Environmental Coalition (IEC) employee McKay Lowder uses a manipulator to take process samples following the treatment of sodium-bearing waste at the Integrated Waste Treatment Unit at the Idaho National Laboratory Site. IEC employee Alan Middleton, background, supports the effort.

IDAHO FALLS, Idaho — Since beginning radiological operations in April 2023, the Integrated Waste Treatment Unit (IWTU) at the Idaho Cleanup Project (ICP) has run a successful radiation protection program to control contamination and minimize personnel exposures while the plant converts liquid radioactive waste to a safer granular solid.

IWTU began operations on April 11, 2023, treating 68,000 gallons of the 900,000 gallons of sodium-bearing waste from three nearby underground tanks during the next five months.

During a subsequent outage for maintenance, team members opened IWTU’s cells to replace filters and conduct inspections and repairs. They also designed and built mock-ups, tent enclosures and one-of-a-kind tools; maximized ventilation controls; and continually decontaminated areas to keep personnel exposures to a minimum and contain contamination within the cells themselves.

IWTU Nuclear Operations Senior Director Jimmy Spells said he was pleased with everyone’s preparation and execution of work.

“Preplanning and worker input ensured that our radiological outage was executed safely and efficiently,” he said. “This is especially notable since this was also the first actual radiological work experience for much of the IWTU team.”

Bill Kirby, chief operating officer for ICP contractor Idaho Environmental Coalition (IEC), agreed.

“Exceptional planning with the involvement of radiological engineering, operations, work control, and system engineering really made the difference,” he said. “Our use of mock-ups and dry runs gave people the confidence that this challenging work could be done safely, and they delivered.”

Process gas filter bundle replacement was particularly challenging because of high radiation and contamination levels. During radiological operations, gases along with light particles generated in the Denitration Mineralization Reformer — IWTU’s primary reaction vessel – are drawn to the process gas filter, which filters out fine solids. The process gas filter consists of 18 bundles containing long, cylindrical ceramic filters.

“Personnel successfully replaced all 18 process gas filter bundles and kept exposure levels an order of magnitude below allowable U.S. Department of Energy annual limits,” said Radiation Protection, Safety, Health & Fire Protection Senior Manager Allen Nellesen.

Since resuming radiological operations in August last year, IWTU has operated reliably and has treated more than 160,000 gallons of sodium-bearing waste — more than 228,000 gallons overall.

“The IWTU radiation protection monitoring program is paramount to that successful waste treatment track record,” Nellesen said.

The program continuously tracks and trends dose rates and contamination levels throughout the facility, which allows the organization to react to changing conditions before regulatory limits are reached or issues arise.

-Contributor: Erik Simpson