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National Museum of Nuclear Science & History

Secrecy Unveiled – 1945

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Thursday, June 5, 2014
Smyth Report

News of the atomic bombing of Hiroshima on August 6, 1945 stunned the world. Never before had a weapon of such destructive proportions been used with such devastating effect.

Naturally, many ordinary Americans were curious. Newspapers across the United States and the world were filled with stories that speculated on the potential of this new, “atomic” technology. Many wondered how the United States had come to develop the world’s first nuclear weapon. How long did it take the government to develop this technology? Why was it kept secret? Who worked on the project? Where were the bombs built?

Gradually, reports of a $2 billion U.S. government war project, codenamed the “Manhattan Project,” were released. In anticipation of the bombings of Japan, General Leslie Groves had physicist Henry DeWolf Smyth prepare a report that was to be the official U.S. government history and statement about the development of the atomic bombs.

The Smyth Report was released to the public on August 12, 1945. Its release, only days after the bombing of Nagasaki, and the amount of information it disclosed about the just-revealed Manhattan Project made it a landmark document. The report outlined the development of the then-secret laboratories and production sites at Los Alamos, NM, Oak Ridge, TN, and Hanford, WA, and the basic physical processes responsible for the functioning of nuclear weapons, in particular nuclear fission and the nuclear chain reaction.

As historian Alex Wellerstein explains, the Report is marked by a tension between openness and secrecy, attempting to balance a democratic responsibility to keep the public informed with the need to protect national security. Wellerstein calls the Smyth Report “one of the more improbable things to come out of World War II…right after using said superweapon, they published a book explaining how it was made. I can think of no other parallel situation in history, before or since.”

Click here to read Groves’s foreword and Smyth’s preface to the report.

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