<Li> Operation Greenhouse shots of May 1951 included the first boosted fission weapon test ("Item") and a scientific test that proved the feasibility of thermonuclear weapons ("George"). </Li> <Li> Ivy Mike shot of 1 November 1952, was the first full test of a Teller - Ulam design "staged" hydrogen bomb, with a yield of 10 megatons . It was not a deployable weapon, however--with its full cryogenic equipment it weighed some 82 tons . </Li> <Li> Castle Bravo shot of 1 March 1954, was the first test of a deployable (solid fuel) thermonuclear weapon, and also (accidentally) the largest weapon ever tested by the United States (15 megatons). It was also the single largest U.S. radiological accident in connection with nuclear testing . The unanticipated yield, and a change in the weather, resulted in nuclear fallout spreading eastward onto the inhabited Rongelap and Rongerik atolls, which were soon evacuated . Many of the Marshall Islanders have since suffered from birth defects and have received some compensation from the federal government . A Japanese fishing boat, Daigo Fukuryū Maru, also came into contact with the fallout, which caused many of the crew to grow ill; one eventually died . </Li> <Li> Shot Argus I of Operation Argus, on 27 August 1958, was the first detonation of a nuclear weapon in outer space when a 1.7 - kiloton warhead was detonated at an altitude of 200 kilometres (120 mi) during a series of high altitude nuclear explosions . </Li>

Where does the us store their nuclear weapons