Nuclear History archive — page 6
The Manhattan Project's Scale and Legacy
The Manhattan Project cost about $1.89 billion by the end of 1945, mostly for the Oak Ridge and Hanford production plants, employed about 129,000 people at its peak, and passed to the civilian Atomic Energy Commission on 1 January 1947.
The Demon Core Accidents (1945–1946)
The same plutonium core went prompt critical twice at Los Alamos, killing Harry Daghlian in 1945 and Louis Slotin in 1946 and ending hands-on criticality experiments.
The Smyth Report, 1945
Released on 12 August 1945, Henry Smyth's official account, written under three release tests drafted with Richard Tolman, sold about 127,000 copies in its Princeton edition and was printed in about 30,000 Russian copies in January 1946.
The ABCC, RERF and the survivor studies
Launched by Truman's directive of 26 November 1946 and reborn as the joint Japanese–American RERF on 1 April 1975, the survivor studies followed about 120,000 people and found, for example, that about 46% of leukaemia deaths and 11% of solid cancers in the cohort were attributable to radiation.
Did the Bomb End the War? Japan's Surrender
Two atomic bombs and the Soviet declaration of war came within three days in August 1945; Japan's leaders needed two imperial decisions to surrender, and orthodox, revisionist, Soviet-entry and synthesis interpretations still weigh the causes differently.
The Atomic Bombing of Nagasaki (1945)
On 9 August 1945 Bockscar abandoned cloud- and smoke-covered Kokura and dropped Fat Man on Nagasaki at 11:02 a.m.; death estimates range from about 25,000 to over 70,000 depending on the source.
Hiroshima, August 6, 1945
At 8:15 a.m. on 6 August 1945 the Enola Gay dropped Little Boy on Hiroshima; it burst about 600 m up with a yield of about 15 kt, and death estimates by the end of 1945 range from about 66,000 to about 140,000 depending on the source.
The Potsdam Declaration and the Order to Bomb (1945)
On 25 July 1945 General Handy ordered the 509th Composite Group to bomb one of four Japanese cities after about 3 August; on 26 July the US, Britain and China issued the Potsdam Declaration without mentioning the bomb or the emperor, and on 28 July Prime Minister Suzuki's 'mokusatsu' was read as rejection.
The Trinity Test (1945)
On 16 July 1945 the plutonium Gadget exploded atop a 30 m tower at Trinity, yielding 21 kilotons (24.8 ± 2 kt in a 2021 re-analysis) and spreading fallout beyond the desert.
The Interim Committee (1945)
Set up by Secretary of War Stimson in May 1945, the Interim Committee advised on 1 June that the atomic bomb be used against Japan as soon as possible and without warning; Ralph Bard's later dissent and the unrecorded demonstration debate show how layered the decision was.