RICHLAND, Wash. (AP) — The world's first full-scale nuclear reactor, built in 13 months to produce plutonium for an atomic bomb during World War II, is now a National Historic Landmark, the federal government announced Monday.

The Hanford nuclear reservation's B Reactor produced plutonium for the first man-made atomic blast, the Trinity test in New Mexico on July 16, 1945, and for the bomb that was dropped on Nagasaki, Japan, on Aug. 9, 1945.