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Hanford History

The Hanford Site sits on 586-square-miles of shrub-steppe desert in southeastern Washington State.  Beginning in 1943, the site was used to produce plutonium for the bomb that brought an end to World War II.  After a short lull, production was ramped up in 1947 to meet the challenges of the “Cold War” and continued until 1987 when the last reactor ceased operation.  Weapons production processes left solid and liquid wastes that posed a risk to the local environment including the Columbia River. In 1989, the U. S. Department of Energy (DOE), Environmental Protection Agency (EPA), and Washington State Department of Ecology entered into a legally binding accord, the Tri-Party Agreement (TPA), to clean up the Hanford Site.

Before the Reactors 

White Bluffs Street, 1938

For centuries, the Hanford area bordering the Columbia River was home to several tribes of Native Americans.  Remnants, artifacts, and burial sites associated with historical Native American activity are found throughout the Site and are protected by law.  The mid-1800’s brought pioneers and settlers to the mid-Columbia.  The small towns of White Bluffs and Hanford sprang up to support the farms and ranches of early residents.  When the War Department decided to locate portions of the Manhattan Project in this part of Washington, it also decided that work to develop atomic weapons had to be done in secret. Subsequently, in early 1943, all of the residents of White Bluffs and Hanford were told to evacuate their homes and abandon their farms, and were given just 30 days and a small amount of money to do so.


World War II Era

B Reactor

After the residents of White Bluffs and Hanford moved away, the War Department began the process of recruiting workers to build nuclear reactors and processing facilities required to extract plutonium for atomic weapons. People from all over the country came to Hanford, ultimately forming a 51,000 person workforce.  Very few of the workers knew what they were building or what these facilities would do once they were completed.  Hanford employees believed they were doing important war work, but beyond that, they knew few details.  Under the careful supervision of such noted scientists as Enrico Fermi, crews began the process of building production reactors at Hanford.  Workers also built two massive processing facilities called “canyons”, where plutonium would be extracted from uranium “fuel rods” after removal from the reactors. Hanford’s ultimate triumph came with the nuclear explosion above Japan in August 1945, effectively ending World War II.



Cold War Era

 President John F. Kennedy visited the Hanford Nuclear to dedicate the groundbreaking of the steam generator for the N-reactor

Post World War II tensions between the U.S. and Russia brought about the “Cold War” and drove continued atomic weapons production and Hanford’s plutonium production mission.  Additional reactors were constructed next to the Columbia River as the two nations began to develop and stockpile nuclear weapons.  In 1959, construction began on the last Hanford reactor, dubbed “N.” N Reactor was a dual-purpose facility which produced plutonium for atomic weapons as well as steam for generating electricity. It was the only dual-purpose reactor in the United States and was so advanced that President John F. Kennedy came to Hanford in September of 1963 for its dedication.  Starting in the mid 60’s through 1971, the older reactors were shut down leaving only N Reactor operating on the Site.  N Reactor continued its mission of producing plutonium and electricity until 1987.  Since that time Hanford’s mission has been to clean up the site after decades of weapons production activities.





Last Updated 03/21/2021 2:30 PM