1939 January to May - Many experiments on uranium fission are performed worldwide. 1941 January - Based on experiments with a natural uranium reactor, the Germans reject graphite as a moderator. 1945 January - First plutonium reprocessing production run at Hanford
January 20 - First U-235 separated at Oak Ridge. 1950 January 27 - Fuchs confesses that he gave atomic secrets to the Soviets. More »
January 31 - Truman announces the decision to proceed with the H-bomb. More » 1954 January 21 - First nuclear-powered submarine, U.S.S. Nautilus, launched. 1966 January 17 - U.S. B-52 bomber crashes near Palomares, Spain with 4 unarmed H-bombs. More » 1967 January 27 - Outer Space Treaty bans nuclear weapons being placed in orbit. More » 2003 January 10 - North Korea announces it will withdraw from the Nuclear Non-Proliferation Treaty. 2004 January 27 - Pakistani investigators have concluded that Abdul Qadeer Khan, considered the father of Pakistan's nuclear bomb -- provided unauthorized technical assistance to Iran's nuclear weapons program in the late 1980s. 2016 January 6 - North Korea annouces it had conducted a test of a hydrogen bomb. It is unclear the true nature of nuclear test.