Historic Hanford B Reactor

The B-Reactor at Hanford Site, Washington, was the first large scale plutonium production reactor ever built. The project was commissioned under the Manhattan Project, during World War II, to develop the first nuclear weapons. The B Reactor was one of three reactors—along with the D and F reactors—built about six miles apart on the south bank of the Columbia River. The plutonium for the Trinity device, tested at Los Alamos in New Mexico, and the Fat Man bomb, later dropped on Nagasaki, Japan, was created in the B, D and F reactors.