Two decontamination vessels that are essential to safely removing canisters of glassified radioactive waste produced at the Hanford vitrification plant's High Level Waste Facility have been delivered to the project.
The titanium steel vessels weigh 4,200 pounds and measure 2.5 feet in diameter and 18 feet tall.
Inside each vessel, canisters of treated radioactive waste will be cleaned of any radioactive contamination with acid that will etch off a fine layer from the exterior of the canister before it leaves the building.
When the plant begins operating, the High Level Waste Facility will vitrify, or glassify, high level radioactive waste by mixing it with glass-forming materials and heating the mixture to 2,100 degrees in one of two 90-ton melters. The mixture then will be poured into a stainless steel canister and an overhead crane will move it from the melter area, through a triple set of protective shield doors and to a decontamination vessel.
It then will be inserted into the vessel and decontaminated through "etching," a process that removes an almost sheer layer from the vessel's exterior with an acidic compound. This will be done using the vessel's complex coil-and-spray system.
The canister also will be rinsed with nitric acid and demineralized water before it is removed from the facility.
"The canister decontamination process is extremely thorough, using proven technology to ensure that risks to people and the environment are removed," said Joe St. Julian, Bechtel National area project manager for the facility.
The process will take about 12 hours.
The decontamination vessels, which were manufactured by Titanium Fabrication Corp. of New Jersey, are scheduled to be installed next year.
The High Level Waste Facility is making good progress toward construction being completed in 2016, said Gary Olsen, Department of Energy area project manager for the facility. It's one of four major facilities at the vitrification plant, which is required to begin treating waste in 2019. Both low activity and high level radioactive waste will be treated.