The 200 Area at Hanford is known as the Central Plateau. It is the part of the Site which is the highest in terms of its elevation. There are actually three regions associated with the 200 Area (the 200 East Area, the 200 West Area, and the 200 North Area) which are separated from each other by several miles. The 200 Area makes up about 75-square-miles of the Hanford Site and is home to many cleanup projects and remediation efforts involving both solid and liquid wastes.
The main function of the facilities in the 200 Area of Hanford was to remove the plutonium from the uranium fuel rods after they had been subjected to the nuclear chain reaction in the 100 Area reactors. Five massive processing facilities called “canyons” were where these activities took place. They were called canyons because each of them is about three football fields long, with walls extending sixty feet above the ground and dropping another forty feet below it.
Associated with the removal of plutonium from the fuel rods was the management of the waste generated by the removal process. Billions of gallons of liquid wastes were both intentionally and unintentionally put onto the ground at the Site. These liquids soaked into the ground at the Site and have created some “plumes” of contamination which must be monitored and the contamination treated. Some of the most hazardous chemical and nuclear wastes were put into 177 underground storage tanks spread out into eighteen groups of tanks called tank farms. The storage tanks range in size from 50,000 gallons of capacity to more than 1,000,000 gallons of capacity. Currently at Hanford, some 53,000,000 gallons of chemical and nuclear waste remain stored in these tanks.
Hundreds of solid waste sites are also located in the 200 Area. These sites are places where waste filled drums and boxes, or even just random waste materials were buried. These wastes are removed from the ground and are characterized and identified to determine where they will be sent for permanent disposition.
While much of Hanford’s current mission revolves around the demolition of buildings and facilities, there are two construction projects underway in the 200 Area which are critical to the safe removal of the solid and liquid wastes at Hanford. The Waste Treatment Plant is being built to process the 53,000,000 gallons of liquid waste currently being stored in the the tank farms. The process is called vitrification, where the liquid wastes are mixed with glass making materials and then heated to form a red-hot, molten substance that is poured into steel cylinders. Once the material is cooled, the waste will have been captured in a glass form which is considerably more stable than liquid wastes are. These cylinders of vitrified waste will ultimately be sent to a national repository where they will be buried permanently in a specially approved and regulated facility.
The Environmental Restoration Disposal Facility, called “ERDF”, is located on the Central Plateau between the 200 East and West Area. ERDF is a massive landfill that is regulated by the United States Environmental Protection Agency. ERDF accepts materials that come from building demolition projects and solid waste burial ground excavations at Hanford. The newest cells are “super cells” 9 and 10. These cells are the largest at ERDF and each super cell is basically equivalent in size to two regular ERDF disposal cells.
Besides the burial grounds, waste tanks, ERDF, and Waste Treatment Plant the 200 Area also features hundreds of other facilities and structures. Many of these facilities were critical to the processing of plutonium, while others were office buildings or related to the infrastructure needs of the Site. Some remain in use today as the cleanup mission at Hanford continues while others have long since been abandoned and are scheduled to be demolished in the future or have already been brought down.