Diana Preston - Before the Fallout

As the Manhattan Project progressed, the American authorities deployed ever-increasing resources on research on health effects. Because of worries about security in the wide number of universities and other academic institutions involved, a new term— health physics —was used to embrace all radiation protection activities. The use of 100 hamsters, 200 monkeys, 675 dogs, 1,200 rabbits, 20,000 rats, 277,400 mice, and 50 million fruit flies in radiation experiments at one research establishment alone gives some indication of the scale of the work. Experiments were carried out on humans, sometimes without their knowledge or consent. The case of Ebb Cade, a black Oak Ridge worker, was one of the most shocking. After a car accident he was taken to the hospital with broken limbs. Without his consent he was injected with plutonium. While still in the hospital, fifteen of his teeth were extracted and bone samples taken to see how the plutonium had migrated around his body. [34] The scale of experiments on humans came to light in 1996 in a report by the President’s Advisory Committee on Human Radiation Experiments. Describing tests on some fifty people, the report concluded that “patient subjects… were never told that the injections were part of a medical experiment for which there was no expectation that they [would] benefit, and [to which] they never consented.”

Louis Hempelmann had been in charge of health safety at Los Alamos from the start, establishing limits for radiation exposure and developing ways of monitoring radiation levels. With the arrival of plutonium in 1944, his role intensified as he set rules for the handling of plutonium and lectured teams about its extreme toxicity. Philip Morrison recalled, “We had film badges, ionising gauges, counters. We were very seriously monitored.” There were no immediate radiological fatalities during the war, but there were serious incidents born of inexperience and carelessness. While leaning for a couple of seconds over blocks of U-235 in an assembly he nicknamed “Lady Godiva” because of its unshielded nakedness, Otto Frisch noticed out of the corner of his eye that the little red signal lamps, which flickered according to the number of neutrons being emitted, were “glowing continuously.” His body had “reflected some neutrons back into Lady Godiva and thus caused her to become critical.” Hastily, he leaned back and removed some of the uranium blocks. He calculated that during those two seconds “the reaction had been increasing, not explosively but at a very fast rate, by something like a factor of a hundred every second.” The radiation dose he had received was fortunately small, but “if I had hesitated for another two seconds before removing the material… the dose would have been fatal.”

The Los Alamos teams were indeed engaged in dangerous work. According to Philip Morrison, “We had the temerity to ‘tickle the dragon’s tail’ by forming a supercritical mass of uranium. We made a much subdued and diluted little uranium bomb that we allowed to go barely supercritical for a few milliseconds. Its neutron bursts were fierce, the first direct evidence for an explosive chain reaction.” Such evidence gave Oppenheimer confidence that the calculations for the uranium bomb were accurate and that the gun-assembly method would work. He advised Groves that, with a war on, the army should take possession of the uranium bomb, Little Boy, untried. Groves, convinced that the technology was straightforward, and reassured by the exhaustive testing of the actual gun mechanism by Deak Parsons’s ordnance team, readily accepted the advice.

Fat Man was a different matter. There was, as Peierls recalled, “much more room for doubt in the case of plutonium which depended on the very complex implosion technique.” The scientists’ advice was that the plutonium bomb had to be tested. Groves at first objected, fearing that if the test failed, his precious plutonium would be scattered across the desert. However, as he later wrote, he was eventually persuaded of the need to check that “the complex theories behind the implosion bomb were correct, and that it was soundly designed, engineered, manufactured and assembled—in short, that it would work.” What particularly swayed him was the argument that if the plutonium bomb failed to detonate when deployed, the enemy would be presented with a fine gift of plutonium.

In March 1944 detailed planning began at Los Alamos for a test of a plutonium implosion bomb. Oppenheimer, recognizing the somber significance of what would be humankind’s first nuclear explosion, searched for a suitable code name. He chose “Trinity” for reasons that he never fully explained, although in a postwar letter to Groves he would suggest his inspiration derived in part from a devotional poem by the English seventeenth-century metaphysical poet John Donne beginning, “Batter my heart, three person’d God.”

As the bombs came closer to reality, the misgivings of some scientists at Los Alamos grew. Joseph Rotblat’s only motivation for working on the bomb had been the fear that the Germans would get there first. However, from his first days at Los Alamos he had been uneasy. As he recalled, “When I saw the magnitude of the project at Los Alamos, how many people worked there, how no effort was spared, no money, I could see straightaway that, even with all this, it would take a long time before the bomb was made. The Germans could never match it. In 1944 Germany was being bombarded day and night, industry was being destroyed. It would have been impossible for them to do anything like this in the conditions.”

Rotblat’s anxiety heightened when, in March 1944, during dinner at James Chadwick’s house he heard General Groves declare that “the real purpose in making the bomb was to subdue the Soviets.” Rotblat was not a communist. Like Marie Curie, he was a Polish patriot highly conscious of Russia’s long suppression of his native land. However, Groves’s belligerence toward the Soviet Union was, as Rotblat later recalled, “a terrible shock—I had been a bit naive, an idealist, I thought we are all fighting together against a mortal enemy and here we are on the other hand doing something against the person who counts as our ally.”

Rotblat shared his worries with Niels Bohr, one of his closest friends at Los Alamos. As Rotblat remembered, “We hated the U.S. news—ten seconds of news, then fifteen seconds of ‘Ex-Lax’ ads.” Instead they listened to the BBC World Service on Rotblat’s shortwave radio. Afterward, they would talk long into the night. Bohr “inspired” Rotblat with “thoughts of scientists’ responsibilities.” He also told him his ideas for a system of international control to head off a postwar arms race. He believed passionately that the three great powers—the United States, Britain, and the Soviet Union—had to agree on how atomic energy should be applied and controlled before the bomb was completed and deployed. This meant telling the Russians about the Manhattan Project and subsequently making arrangements for the internationalization of knowledge for the benefit of all.

Bohr’s international stature meant that he had contacts on both sides of the Atlantic willing to help him take his views to the highest level. Indeed, when he had first visited the United States after fleeing from Denmark, he had discussed his fears of a nuclear arms race with the U.S. supreme court justice Felix Frankfurter, an adviser to President Roosevelt whom Bohr had known since 1933. Frankfurter had passed Bohr’s comments on to the president, who eventually sent back a noncommittal message that he was interested to know Churchill’s reactions to Bohr’s views.

Bohr responded readily to the implied invitation to go to England, flying there in April 1944. Churchill was not, however, keen on meeting him. Lord Cherwell, another old acquaintance of Bohr’s, was unable to secure a meeting for Bohr with the prime minister until May, and it was not a success. There was no empathy. At one point Churchill turned to Cherwell to demand, “What is he really talking about? Politics or physics?” To Bohr there was no difference. To Churchill politics was strictly his and Roosevelt’s sphere. He was left appalled by what Bohr had had to say, believing his advocacy of openness to be highly dangerous. In his opinion, Bohr “ought to be confined or at any rate made to see that he is very near the edge of mortal crimes.” He also took a strong personal dislike to the celebrated Dane, writing resentfully to Cher­well, “I did not like the man when you showed him to me, with his hair all over his head.” Bohr, in turn, was shocked by Churchill’s attitude: “It was terrible. He scolded us [Bohr and Cherwell] like two schoolboys.”