A first-of-its kind facility to convert sodium-bearing waste at the Department of Energy’s Idaho National Laboratory into a solid form, is likely to stay offline for maintenance at least a few more weeks, an advisory board heard Wednesday.
The Integrated Waste Treatment Unit (IWTU) is using a maintenance outage that began in September to replace granulated activated carbon beds, used for mercury removal, said Nicholas Balsmeier. These mercury-removal beds must be replaced periodically, said Nicholas Balsmeier, DOE’s assistant manager for programs at the lab’s Idaho Nuclear Technology and Engineering Center.
Balsmeier did not offer a projected restart date, but suggested the maintenance work will likely continue for a month or so. The IWTU has treated 68,000 gallons of sodium-bearing waste at Idaho National Laboratory and has about 773,000, more than 90%, left to go, he said.
The beds absorbed as much mercury as possible prior to being changed out, Balsmeier said. “So, this wasn’t something we didn’t think through or something that was a surprise to us,” he told the Citizens Advisory Board for the Idaho Cleanup Project. “We knew that it would happen.”
The sodium-bearing waste, a byproduct of nuclear fuel reprocessing at the Idaho National Laboratory, contains much mercury, Balsmeier said in reply to a question from the board. Replacement comes “maybe slightly earlier” than planned, he said.
The granulated activated carbon bed replacement will take place “over the next few weeks to month,” Balsmeier said, “and then we will continue to get ready to come back online.” There are other maintenance items that can only be done while the IWTU is offline, he added.
This includes replacement of coal and coke additive feed transfer lines, Balsmeier said. “Coal and coke are really what operate” key elements of the steam reforming technology used to turn liquid waste into a granular form for eventual disposal, he added.
“We say that IWTU just started up [in April], but it’s really been running through various simulant runs, testing and start since 2012,” Balsmeier said.
A CH2M-led contractor initially finished construction and hoped to start up the facility in 2012, but the plant did not operate as envisioned. Over time, successor prime contractors Fluor Idaho and now the Jacobs-led Idaho Environmental Coalition made a combined 50 modifications or so to the IWTU, Balsmeier said.
During the ongoing outage, crews will also complete installation of an onsite nitrogen generating system to reduce reliance on outside vendor deliveries, Balsmeier said in the presentation. The current thinking at DOE is that it will take DOE to take up to seven years to solidify the sodium-bearing waste, he added, in response to a question.
Also during the advisory committee meeting, DOE contracting officer Maria Mitchell-Williams said the IWTU contract requirements are not tied to calendar-based milestones, largely because that approach has not worked for the facility in the past.
