B Reactor Museum Association - B Reactor Museum Association B Reactor the showplace of theManhattan Project National Historical Park B Reactor Museum Association Richland Washington USA Who we are BRMAmembers at B Reactor Helpful information about B Reactor B Reactor Awaits You About B Reactor BReactor the worlds first industrialscale nuclear reactor was built during World War II as part of the topsecret Manhattan Project to develop the atomic bomb. One of three plutonium production reactors built in total secrecy at Hanford during World War II B Reactor produced plutonium for the Trinity test at Alamagordo New Mexico on July 16 1945 and for the atomic bomb exploded on Nagasaki on August 9 1945. B Reactor is included in the Manhattan Project National Historical Park consisting of historic facilities at Hanford Los Alamos and Oak Ridge which was authorized by Congress in December 2014. A Memorandum of Agreement between the National Park Service and the Department of Energy was signed on November 10 2015 formally establishing the Manhattan Project National Historical Park.