The Department of Energy was eyeing an “easy fix” for the Integrated Waste Treatment Unit in Idaho, knocked offline Feb. 26 during the final demo run preceding treatment of nearly 1 million gallons of liquid radioactive waste, an agency official said here Tuesday.
The long-delayed Integrated Waste Treatment Unit (IWTU) was processing a simulant, non-radioactive liquid when, about 17 days into a planned 50-day demo, operators shut it down because of fluctuations in operating temperatures and gas concentrations within the unit.
After letting IWTU sit idle for a week in a planned cooldown period, the culprit turned out to be a “loose filter,” Joel Case, DOE’s assistant manager for facility and material disposal at the Idaho Cleanup Project, said Tuesday during the annual Waste Management Symposia in Phoenix.
“The good news is it looks like an easy fix and we will get that back up,” Case told the audience at the annual industry gathering, held again in Phoenix this year after going virtual in 2021 because of COVID-19.
IWTU is designed to solidify 850,000 to 900,000 gallons of liquid, sodium-bearing waste at the Idaho National Laboratory left over from nuclear fuel reprocessing. The resulting granular substance is supposed to be stored in steel canisters until the federal government builds a permanent radioactive waste disposal facility.
Instead of turning liquid radioactive waste into glass cylinders, as DOE’s Defense Waste Processing Facility has done for years at the agency’s Savannah River Site or as the planned Waste Treatment and Immobilization Plant is supposed to do at the agency’s Hanford site, IWTU will use steam reforming to solidify liquid waste for storage.
The oil and gas industry uses steam reforming to extract hydrogen from natural gas by using water vapor, high temperatures and a catalyst to isolate the gas’ hydrogen molecules.
Also at the show Tuesday, Jim Folk, assistant manager of waste disposition at DOE’s Savannah River Site in South Carolina, said the Salt Waste Processing Facility (SWPF) is running well since restarting a few weeks ago. Since it restarted Feb. 11, it has treated more than 280,000 gallons of waste over 25 days, Folk said.
A combination of safety concerns and operating challenges kept the SWPF offline since late October. “It’s running very, very well when it’s up,” Folk said.
The plant built by Parsons will be turned over in about three weeks to BWX Technologies-led Savannah River Mission Completion, the new liquid waste contractor at Savannah River.
The SWPF removes the highly radioactive cesium and strontium from the less radioactive salt solution from underground tank waste. After going through the SWPF the highly-radioactive material is converted into a stable glass form at Savannah River’s Defense Waste Processing Facility. The leftover salt solution goes to the above-ground saltstone disposal units.
DOE’s Office of Environmental Management at Savannah River has challenged the new contractor to “finish in 15,” said Savannah River Mission Completion President David Olson. This means treating the remaining 43 million gallons of radioactive liquid tank waste at the site within 10 years and completing most other major waste cleanup within five years, Olson said.
“It’s all there in place,” Olson said of the technology needed for radioactive waste, adding that it just needs to be optimized.
