The Department of Energy has yet to resume its final test run of the Integrated Waste Treatment Unit at the Idaho National Laboratory, the agency confirmed Thursday.
“The IWTU remains shut down,” an Idaho Department of Environmental Quality official said by email Thursday. “They [DOE managers]have completed their investigation and are preparing to start warming up but have no date as to when that will be.”
A 50-day demonstration run of the long-anticipated Integrated Waste Treatment Unit (IWTU) was suspended Feb. 26 after swings in operating temperatures and gas concentrations within the unit, DOE has said.
The IWTU remains in an unplanned outage resulting from “de-fluidization” of the Carbon Reduction Reformer (CRR) bed in late February, a federal spokesperson said by email Monday. The cause of the problem is excess carbonate carryover to the CRR from the Process Gas Filter (PGF), according to the spokesperson.
“Inspections and development of corrective actions are ongoing, thus we do not have a firm schedule to resume the confirmatory run,” said the DOE spokesperson, who said there was no status change Thursday.
The Feb. 26 suspension was not the first snag connected with the demonstration run. After fixing a value that was installed backwards in December, work crews took the unit offline Jan. 6 largely due to supply problems with nitrogen. The test run then restarted Feb. 17 and it ran nine days before the latest disruption.
The final test run, using a simulant rather than actual radioactive waste, is a dress rehearsal for the plant designed to convert between 850,000 and 900,000 gallons of sodium-bearing liquid waste into a more stable granular form for eventual disposal. The sodium-bearing waste is left over from years of spent nuclear fuel reprocessing at what is now the laboratory’s Idaho Nuclear Technical and Engineering Center (INTEC).
Last month, Ty Blackford, president of Jacobs-led contractor Idaho Environmental Coalition, said the filter problem should be an easy fix. The IWTU works but needs to be able to run consistently and reliably, Blackford said while attending the Waste Management Symposia in Phoenix.
The plant was first built for DOE in 2012 by contractor CH2M-WG Idaho but never worked as intended. The following contractor, Fluor Idaho, re-engineered much of the plant over the years. The Idaho Environmental Coalition became the new cleanup contractor at the Idaho National Laboratory in January.
