IDAHO FALLS, Idaho - A team helping improve the Idaho Site 's Integrated Waste Treatment Unit (IWTU) added an entrance to the facility’s primary reaction vessel to replace damaged equipment.
Welders and pipefitters with a Denitration Mineralization Reformer (DMR) project team secured an 18-inch manway onto the 2-inch-thick DMR vessel. This allows for removal of the internal ring header damaged by erosion in prior waste simulant runs. The ring will be replaced with an alternative system that introduces the gases necessary to keep treatment media and waste moving in a fluidized motion inside the reaction vessel.
Workers welded the manway after a hole was cut in the DMR by a mobile waterjet subcontractor. The DMR’s Haynes 556, a stainless steel alloy - manufactured for high temperatures and corrosive operating conditions, but prone to cracking during welding - proved challenging
“There were a few times that all of us thought this thermally aged material might be impossible to weld on, but we all took the challenge and proved the impossible could be done," Fluor Idaho Project Manager Scott Shurtliff said. “Our welders are now, quite literally, the world’s foremost experts on working with Haynes 556 of this thickness, and it’s been with the help of the whole team."
Tests showed the welders performed the task perfectly.
“They did an excellent job as there were no unacceptable indications found," said Shurtliff.
EM and Idaho Cleanup Project contractor Fluor Idaho are preparing for the IWTU’s second simulant demonstration: a 30-day run to test the fluidization improvements.
Ultimately, the IWTU will use a steam-reforming technology to treat 900,000 gallons of liquid radioactive waste stored in three underground stainless-steel tanks.
Source: U.S. Dept. of Energy, Office of Environmental Management
