Skip to main content
About Us

200 Area

Hanford’s 200 Area, known as the Central Plateau, is home to many cleanup projects and remediation efforts involving both solid and liquid wastes. The area is made up of the 200 East and 200 West areas, which are separated by several miles. The area makes up about 75-square miles.

200 West and 200 East Area
Aerial of the Waste Treatment & Immobilization Plant (bottom), 200 East Area (middle) and 200 West Area (top). Photo circa Sept. 2021.


The main function of the facilities in the 200 Area was to remove plutonium from uranium fuel rods after they had been subjected to the nuclear chain reaction in the 100 Area reactors. Five massive processing facilities called chemical separation plants, or “canyons,” were where these activities took place. They were called canyons because each of them is about three football fields long, with walls extending 60 feet above the ground and dropping another 40 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 waste were both intentionally and unintentionally discharged onto ground at the Site. These liquids soaked into the soil and have created some “plumes” of contamination that must be monitored and remediated.

Some of the most hazardous chemical and nuclear wastes were put into 177 underground carbon-steel storage tanks spread out into 18 groups of tanks called tank farms. The storage tanks range in capacity from 50,000 gallons to more than 1,000,000 gallons. Currently, some 56 million gallons of chemical and radioactive waste remain stored in 158 of Hanford’s total 177 tanks, with the others being successfully retrieved.

Hundreds of solid waste sites are also located in the 200 Area. These sites are places where waste-filled drums and boxes and other waste materials were buried. The solid waste is removed from the ground, characterized, and identified to determine where it will be sent for permanent disposal.

While much of Hanford’s current mission revolves around the demolition of buildings and facilities, there is a construction project currently in the commissioning phase in the 200 Area that is critical to the safe removal of the solid and liquid waste at Hanford. The Waste Treatment and Immobilization Plant will process a portion of the 56 million gallons of liquid waste currently being stored in the tank farms. The waste will be treated with a process called vitrification, in which the liquid wastes are mixed with glass-forming materials and heated to form a red-hot, molten substance that is poured into steel containers. Once the material is cooled, the waste will be captured in a stable glass form. The cylinders of vitrified waste will be sent to the Integrated Disposal Facility onsite for permanent disposal.

The Environmental Restoration Disposal Facility (ERDF) is located on the Central Plateau between the 200 East and West Areas. ERDF is a massive, engineered landfill regulated by the U.S. Environmental Protection Agency supports sitewide cleanup activities.

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 continues, while others are no longer used, demolished, or scheduled to be demolished in the future. 

200 West and 200 East Area
Aerial of the Waste Treatment & Immobilization Plant (bottom),200 East Area (middle)
and 200 West Area (top).Photo circa Sept. 2021.




Last Updated 08/03/2022 11:28 AM