The Interior Dept. has designated the B Reactor at the U.S. Energy Dept.’s Hanford former nuclear weapons production site in Washington state as a national historic landmark for its role in ending World War II. The structure was the world’s first industrial-scale nuclear reactor, producing plutonium for the second and final atomic bomb dropped on Nagasaki, Japan, in August 1945. DOE says it will open the reactor, previously rumored for demolition, to the public next year. Interior Secretary Dirk Kempthorne formally signed off on the reactor’s new status on Aug. 19.