Low-Activity Waste (LAW) Facility
The Low-Activity Waste (LAW) Facility will be used to vitrify the low-activity waste received from the Hanford Tank Farms, where the waste is stored. After vitrification, the waste will be in a stable and solid form.
The LAW Facility will receive pretreated low-activity waste that will then be mixed with silica and other glass-forming materials. The mixture will be fed into the LAW Facility’s two massive melters and heated to 2,100 degrees Fahrenheit.
The melters weigh 300 tons each and are approximately 20 feet by 30 feet and 16 feet high. They are the largest waste glass melters in the world and nearly five times larger than the 65-ton melter in operation at the Department of Energy Savannah River Site's Defense Waste Processing Facility in South Carolina.
After heating, the glass mixture will be poured into stainless steel containers, which each weigh more than seven tons empty. They are four feet in diameter and seven feet tall. That glass will consist of about 20 percent waste and 80 percent additives.
The LAW Facility is 330 feet long and 240 feet wide, approximately the size of one and a half football fields, and 90 feet, or seven stories, high.
Once filled, the low-activity waste containers will be transported and stored on the Hanford Site in permitted trenches and covered with soil at the Integrated Disposal Facility. The facility will annually produce approximately 1,100 containers.
After years of commitment to the safety and quality of the Vit Plant, the LAW Facility is complete and nearing operations as part of the Direct-Feed Low-Activity Waste approach.
A Closer Look
The Control Room
The control room is the brains of Direct-Feed Low-Activity Waste operations at the Vit Plant. Workers monitor plant systems from inside a computerized control in an annex attached to the LAW Facility. In the control room, trained and qualified workers use sophisticated software to monitor and control systems for the LAW Facility, Analytical Laboratory, and Balance of Facilities.
The Process Cell
The process cell consists of six large stainless steel vessels: three for feeding waste to two low-activity waste melters and three for treating the melters’ offgas.
The feed vessels include a concentrate receipt vessel that receives waste feed; a melter feed preparation vessel that mixes the waste feed with glass formers; and another melter feed vessel that supplies the mixed waste feed to the melters.
The three offgas treatment vessels are a submerged bed scrubber to cool melter offgas and remove large particulates, a wet electrostatic precipitator to remove finer particulate, and a submerged bed scrubber condensate vessel to store and re-circulate liquid between a scrubber and the vessel.
The Pour Cave Turntables and Elevator
Each low-activity waste melter has two pour spouts leading down to a pour cave with two turntables and elevators. Each turntable has positions for three low-activity waste containers. An elevator raises a container under the melter pour spout. Once filled with glass, the container is lowered to the turntable and rotated to the second position to cool. The third position is for removal of the filled, cooled container and replacement with a new empty container.