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1946 to 1949: Exploring Thermonuclear Weapons

1946 to 1949: Exploring Thermonuclear Weapons

Timeline Image: 
Test at Bikini

October 30, 1949

The General Advisory Committee (GAC) of the Atomic Energy Commission, chaired by J. Robert Oppenheimer, publishes a report on the feasibility of the hydrogen bomb. It recommends that the United States not pursue the development of thermonuclear weapons and instead focus on more advanced fission weapons.

August 29, 1949

The Soviet Union explodes its first atomic bomb in Asia near Semipalatinsk. The RDS-1 explosion yields 22 kilotons of TNT, similar to the Little Boy and Fat Man bombs that were dropped on Hiroshima and Nagasaki. The RDS-1 bomb was an implosion weapon containing a solid plutonium core that was modeled after the American Fat Man bomb.

August 1, 1946

President Truman signs the Atomic Energy Act. This establishes the Atomic Energy Commission (AEC) which assumes responsibility for all Manhattan Engineering District (MED) properties.

July 25, 1946

The U.S. military conducts Shot Baker of Operation Crossroads, a 23 kiloton standard "Fat Man" stockpile weapon exploded underwater at Bikini Atoll. Operation Crossroads was intended to give information about the effect of the atomic bomb on naval vessels. A column of radioactive water severely contaminated ships that were not otherwise destroyed by the explosion.

July 1, 1946

The U.S. conducts Shot Able of Operation Crossroads, its first postwar nuclear test, at Bikini Atoll in the Marshall Islands. The purpose of Operation Crossroads, which included two shots, Able and Baker, was to investigate the effect of nuclear weapons on naval warships. The Able test yielded 23 kilotons.