1944

A second uranium reactor is built at Clinton, Tennessee for manufacturing plutonium for an atomic bomb. [Note: First reactor is Fermi 's in 1942.]

March 13
Barely sixteen months after the feasibility of achieving a self-sustaining nuclear chain reaction was established by Enrico Fermi   in Chicago -- a tightly held secret known only to a very limited number of individuals in the U.S., UK and  Canada -- Homi Jehangir Bhabha initiates efforts to start nuclear research programms in India.

December 8
Joseph Rotblat , Polish refugee and physicist, resigns from the Manhattan Project since he believed that Nazi Germany would not succeed in developing an atomic weapon. He later explains, "I felt there was no need to make a bomb. The only reason I started in 1939 was to stop Hitler using it against us." Rotblat was thereafter barred from entering the United States for 20 years. In 1957 he helped start the Pugwash Conferences on Science and World Affairs, of which he was the first president. In 1995 Rotblat and Pugwash jointly were awarded The Nobel Peace Prize for their work towards the abolition of nuclear weapons.