Brian Bradley
WC Monitor
11/20/2015
Depending on the results of a forthcoming month-long simulation test, the Energy Department will decide whether to change the planned course for disposing of some 900,000 gallons of liquid radioactive waste stored in steel tanks west of Idaho Falls. “Once the simulant run is complete the Department will evaluate plant performance and use that information to determine if an alternative treatment option or modifications to the current process are necessary,” a DOE Office of Environmental Management spokesperson said in an email yesterday. Workers on Nov. 7 started heating up “key equipment” of the Idaho Integrated Waste Treatment Unit (IWTU), the spokesperson said, which is DOE’s official plan to dispose of the waste. Once a steady heat-up progression is achieved, simulant addition will follow, she said.
DOE had hoped to start processing waste at IWTU by the end of last month, but now the plant almost certainly won’t start up until December at the earliest. The IWTU is designed to treat waste using a steam reforming process for disposal, and is intended 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.
