‘Critical’ to Resolve ‘Bark’ Issue Before Waste Processing Can Begin
Mike Nartker
WC Monitor
5/22/2015
While several technical issues remain to be fully resolved, at least one of which has been dubbed “critical,” the Department of Energy is now looking to begin waste processing at the Idaho Integrated Waste Treatment Unit this fall, according to Idaho environmental regulators. This week, DOE informed the Idaho Department of Environmental Quality that it has estimated it could begin waste processing at the facility in October, according to IDEQ Hazardous Waste Compliance Manager Natalie Clough. That would be about a year ahead of a commitment DOE has with the state of Idaho to begin waste processing at the facility by Sept. 30, 2016. “DEQ continues to monitor DOE’s progress in bringing the IWTU up to full operation,” Clough said in a written response to WC Monitor this week.
She went on to say, “There are still issues to be addressed, but we believe DOE and the contractor are working diligently to meet the commitments to the State of Idaho to treat the waste and empty the tanks.” In a separate response, a DOE official noted the Department is doing “everything reasonable” to accelerate the start of waste processing at the IWTU “if possible.”
Facility Remains in Outage Mode Following Initial Simulant Test
The IWTU is intended to treat approximately 900,000 gallons of liquid waste that remains at the Idaho site through a steam reforming process for disposal and to allow for closure of the site’s remaining waste tanks. DOE previously committed to the state of Idaho to have the waste processed by the end of 2012, but in the summer of that year, startup of the IWTU facility was significantly disrupted by what has been described as a “pressure event” that occurred when the facility’s filters became clogged with carbon material during efforts to get it up to its operating temperature. Since then, DOE and contractor CH2M-WG Idaho have been working at another attempt to start up the facility.
In January, start-up of the IWTU reached a significant milestone with the completion of the first round of testing using a waste simulant. Following the completion of the initial simulant test, the facility entered into an outage period to conduct maintenance, modify equipment as necessary, and inspect the effectiveness of previous equipment upgrades. DOE had initially planned for the outage period to be completed in April, but additional time has been needed after the discovery of what the Department has described as “unexpected equipment conditions.”
Such conditions have included the discovery of what has been described as a “bark”-like substance in the IWTU’s Denitration Mineralization Reformer, which is the first of two fluidized beds in the facility’s steam reforming process. The bark issue has been deemed “critical” to resolve and radioactive waste processing cannot begin until then, according to a DOE Office of the Chief of Nuclear Safety presentation, dated March 5, that WC Monitor obtained through a Freedom of Information Act request. “Can’t run rad if forming bark,” the presentation states. “If still forming bark, to run plant would require taking plant down frequently to wash down DMR.” DOE is working to make changes to the DMR bed material to address the bark concerns “and the condition will be reassessed following the next simulant run,” the Department official said.
Next Simulant Run Could Begin in July
According to IDEQ’s Clough, DOE “indicated” this week that the next simulant run at the IWTU could begin near the end of July. “If issues arise that require further correction, more testing and outage time may be necessary,” she said. “The negotiated schedule was designed to allow for several surrogate runs if necessary with sufficient time for inspection and repairs, ensuring the safe and effective operation of the IWTU. Firm oversight by DOE is necessary to encourage the contractor to have the IWTU operationally ready well in advance of the compliance dates.” Clough added, “DEQ remains hopeful that the waste treatment deadlines will be met and steadfast in our commitment to the citizens of Idaho to enforce the terms of the agreement.”
