The Manhattan Project: History and Heritage

By Alan Chodos

"The Manhattan Project: History and Heritage" was one of three sessions, organized by FHP in collaboration with the Division of Nuclear Physics and the Forum on Physics and Society, commemorating the 75th anniversary of the Manhattan Project. Of the three, it was the session most devoted to history, and the one that was specifically organized by FHP.

The first speaker, Cameron Reed of Alma College, undertook the almost impossible task of giving an overview of the Manhattan Project in only 30 minutes. He pointed out, perhaps contrary to most people’s general impression, that at the President’s direction the U.S. was actively investigating the possibility of a fission bomb quite early, a couple of years before the establishment of the Manhattan Project itself. Leading figures in this effort were Vannevar Bush and James B. Conant, and it included eminent physicists like Arthur Compton and Ernest Lawrence.

The Manhattan Engineering District, from which the Manhattan Project took its name, was established in August, 1942, and Colonel (soon promoted to General) Leslie R. Groves was brought in to head it in September. He made the unlikely choice of Berkeley professor Robert Oppenheimer to lead the scientific effort at Los Alamos. Reed stressed how different Groves and Oppenheimer were as individuals, but nevertheless they forged an extremely effective working relationship.

Reed went on to describe the efforts not only at Los Alamos, but also the equally important laboratories at Oak Ridge, Tennessee and Hanford, Washington. The former undertook the enrichment of uranium, using separation by means of both the calutron mass spectrometer (which, Reed emphasized, involved a textbook use of Maxwell’s equations) and of gaseous diffusion. At the latter, three reactors produced plutonium inside uranium rods. These were then transported to special facilities where the plutonium was chemically separated from the uranium in which it had been created.

In the brief time available, Reed then described the designs of the two types of bomb (Little Boy and Fat Man) produced at Los Alamos, and recounted the history of the Trinity test and the use of the bombs on Hiroshima and Nagasaki.

The second speaker, Cindy Kelly, gave a talk titled "Welcome to the Manhattan Project Park!" She is the president of the Atomic Heritage Foundation, which has advocated, since its founding in 2002, for the preservation of the history of the Manhattan Project. After many political twists and turns over a period of about 15 years, in which Kelly and her organization played a major role, Congress enacted the Manhattan Project National Historical Park Act, signed by the President on December 19, 2014.

Uniquely among national parks, the Manhattan Project Park has 3 separate sites, at Los Alamos, Oak Ridge, and Hanford. Kelly pointed out that in fact there are several other sites relevant to the Manhattan Project, for example in New York City, Chicago, Berkeley and Washington DC. She hopes to include these in some fashion in the future.

The Los Alamos site includes several interesting buildings, including what she called the "crown jewel", the house occupied by Oppenheimer and his family. There are other dwellings associated with well-known scientists, and also the "V site", where the plutonium bomb casings were assembled.

At Oak Ridge and Hanford, there is partial access to the facilities, although some of the key structures have been demolished (there are plans to partially reconstruct them), others are still in use, and some are off-limits due to lingering radioactivity.

As Kelly summed up, "The Manhattan Project National Historical Park is a work in progress. It may take several years for the National Park Service to provide interpretive resources and the Department of Energy to restore and allow public access to its sites. However, now that the national historical park is established, we can be assured that the complex story of the making of the atomic bomb will be preserved for generations to come."

The final speaker was John Coster-Mullen, an independent researcher who may be the only "Nuclear Archaeologist" in existence. He is the author of the unique volume "Atom Bombs: the top secret inside story of Little Boy and Fat Man." For more than a quarter century he has been tracking down documents and artifacts related to the Manhattan Project, and has succeeded to such an extent that he has been able to determine the exact specifications of the two Los Alamos bomb designs in exquisite detail and amazing precision. In the course of his researches he has undertaken archaeological expeditions to secret locations in the western U.S., where he has retrieved samples from Fat Man prototypes that were tested in practice bombing runs. He has buried some of the large samples in hopes of one day being able to return with the equipment necessary to transport them. He has also twice visited Tinian, the island in the South Pacific that was the site of the assembly of the bombs used at Hiroshima and Nagasaki, and the takeoff point for the missions that dropped them.

Coster-Mullen’s talk was profusely illustrated with rare photographs of the bombs and the bomb builders. More than once he commented that "they should never have let me see this, but they did." (He stressed, however, that everything he has obtained has been publicly available). Helped by his son, he also displayed a number of actual relics from his archaeological expeditions. The overall impression was of unwavering dedication to finding out the truth about Little Boy and Fat Man, which has provided the public with a wealth of detailed knowledge that would otherwise never have seen the light of day.

John Coster-Mullin

John Coster-Mullin, displaying pieces of Fat Man and Little Boy to the audience

The articles in this issue represent the views of their authors and are not necessarily those of the Forum or APS.