Daigo Fukuryū Maru
Operation Castle was considered by government officials to be a success as it proved the feasibility of deployable "dry" fuel designs for thermonuclear weapons. There were technical difficulties with some of the tests: one device had a yield much lower than predicted (a "fizzle"), while two other bombs detonated with over twice their predicted yields. One test in particular, "Castle Bravo", resulted in extensive radiological contamination. The fallout affected nearby islands including inhabitants and U.S. soldiers stationed there, as well as a nearby Japanese fishing boat (the "Daigo Fukuryū Maru"), resulting in one direct fatality, and then continued health problems for many of those exposed. Public reaction to the tests and an awareness of the long-range effects of nuclear fallout has been attributed as being part of the motivation for the Partial Test Ban Treaty of 1963.