Before the Fallout

by Diana Preston

  As significant quantities of fissionable material began reaching Los Alamos, radiological protection measures were increased. Since the cavalier days of the 1920s, scientists and the public had become increasingly aware of the adverse affects of radiation on those exposed to it. The use of radium in tonics and potions and even face creams sold over the counter had become strictly controlled during the 1930s. The painful death of a wealthy Pittsburgh industrialist, Ebert M. Byers, from the effects of a radium tonic, also advertised as an aphrodisiac, had been a particular catalyst for reform. In line with the instructions, he had daily consumed four doses, each containing two microcuries of radioactive material. The potential for radiation to cause genetic defects in unborn generations had also been recognized since 1927, following work on fruit flies by an American scientist named Herbert Muller. As a consequence, groups of experts had agreed on internationally accepted limits of radiation exposure for both public and workers, albeit considerably more lax than those in force today.

  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 5o 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. *

  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."

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  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, howr 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."

  After Bohr's return to the United States, Frankfurter arranged in August 1944 for the Dane to meet Roosevelt face-to-face. Bohr found the president seemingly more receptive than the British prime minister. However, as events proved, he had not convinced Roosevelt either. With the war in Europe entering a decisive phase after the successful invasion of Normandy, and with the Russians advancing briskly from the East, Roosevelt had no desire to share America's hard-won and expensive secrets with Stalin. In September 1944 he and Churchill agreed to an aide-memoire stating that "the suggestion that the world should be informed regarding Tube Alloys with a view to an international agreement regarding its control and use, is not accepted." They also agreed that "enquiries should be made regarding the activities of Professor Bohr and steps taken to ensure that he is responsible for no leakage of information, particularly to the Russians."

  Before Bohr was allowed to return to Los Alamos, Groves and Chadwick were instructed to interview him in Washington. Churchill had been particularly incensed by reports that Bohr had been in touch with a Russian professor. Bohr explained that the professor was Ernest Rutherford's former protege, Peter Kapitza. Learning of Bohr's flight from Copenhagen, Kapitza had invited him to work in Moscow. Bohr satisfied Chadwick and Groves that he had behaved impeccably—reporting the contact to British intelligence and politely declining the offer. "Mr. Baker" was free to go back to Los Alamos, where he joined in the work on implosion.

  While Bohr continued to fight his ideological battle from within, Joseph Rotblat chose another path—becoming the only key scientist to quit the Manhattan Project during wartime for reasons of conscience. He had only been waiting until he could be "absolutely sure" that the Germans had no bomb. Sufficient proof came at the end of 1944 when Chadwick, who had by then moved to Washington, which was more convenient for him as head of scientific liaison for the British team, visited Los Alamos. Chadwick had access to high-level intelligence reports and confided to Rotblat that there was no evidence of a German atomic bomb. On the strength of this, Rotblat resigned forthwith from the Manhattan Project. As Rotblat remembered, Chadwick "didn't like it," knowing it would cause rupture with the Americans, but he forwarded Rotblat's request to the army authorities. Their response was to present Chadwick with a hefty dossier purportedly proving Rotblat to be a Russian spy. The core of the evidence was that he had told a young woman in Santa Fe that he intended to go to England, join the RAF, and then parachute into Russia or Soviet-occupied Poland to tell the Russians what was happening on "the hill." Rotblat recalled that "within this load of rubbish was a grain of truth." He had indeed talked to someone in Santa Fe, but only with Chadwick's knowledge and approval, and the conversation had not concerned Los Alamos.

  Army intelligence backed down, conceding that the dossier on Rotblat was worthless. However, Chadwick wisely advised Rotblat that he should cite, as his formal reason for wishing to leave Los Alamos, his anxiety about the wife he had been forced to leave in Poland at the start of the war. Groves agreed that Rotblat should leave immediately. Shortly before Christmas 1944 Rotblat traveled by train to the East Coast to stay for a few days with the Chadwicks in Washington. He then caught a train to New York from Union Station, and Chadwick helped him carry on board a large wooden box filled with research notes and personal papers. Curiously, by the time the train arrived in New York Rotblat's box had vanished, and he sailed to England on Christmas Eve without it. Despite many inquiries, the papers, no doubt spirited away by U.S. army intelligence, have never been found. Their disappearance symbolized an almost paranoiac and indiscriminate approach to security as the bomb project approached its final months. Even Chadwick was not immune. When, in January 1945, he wished to visit the British program in Canada, he was told there were strong objections on grounds of security, which, he decided, "it would be most impolitic to ignore."

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  The Anglo-Canadian project was, in fact, giving Groves particular security problems. With the Allied invasion of Europe and the liberation of France in 1944, the refugee French scientists involved as part of the British team wished either to visit their homeland or, indeed, to return for good. Groves, who had done everything he could to exclude them from the Manhattan Project, was appalled at the thought of them taking even their limited knowledge home to France. Groves suspected Joliot-Curie was a communist—as indeed he had become—and would pass whatever he learned from his compatriots straight to Moscow.

  James Chadwick struggled to cool both French and American tempers. He persuaded Bertrand Goldschmidt to be patient and remain in Canada a while longer. However, Hans von Halban, the leader of the French team, insisted on being allowed to return to Europe, and the British agreed. When they learned that he was in London, the Americans demanded assurances that he would not be permitted to travel on to France. They were outraged when, a few days later, he flew to Paris, where he was soon briefing Joliot-Curie. Groves blamed British duplicity, erroneously believing the British were trying to ensure a greater nuclear role for France in the postwar world in exchange for rights to certain French nuclear patents. The affair soured Anglo-American relations. As a British diplomat wrote with tongue-in-cheek reference to Gallic culinary habits, "The salad is heaped in a bowl permanently smeared with the garlic of suspicion." When von Halban returned from France to New York, an embarrassed Chadwick asked Goldschmidt to visit von Halban "to learn as much as possible about what he had said to Joliot-Curie" and then report to Chadwick in Washington. When Goldschmidt, who was perfectly happy to oblige, duly arrived in Washington to report, Chadwick apologetically and naively admitted that he already had "a transcript of everything." The meeting between Goldschmidt and von Halban had been bugged.

  However, unknown to either Groves or Chadwick, the French team in Canada had already succeeded in passing information directly to General Charles de Gaulle. Having learned that the general was to visit the Free French delegation in Ottawa in July 1944, Goldschmidt and his colleagues Pierre Auger and Jules Gueron had told the head of the delegation that "there is something so secret we can't tell you. We must tell de Gaulle direct. We need fifteen minutes." The man had agreed to set up a meeting but insisted that only one of them could meet the general and that he could have only three minutes. The trio decided that Gueron, who had already met de Gaulle, should be the messenger and rehearsed the words again and again. The gist, as Goldschmidt recalled, was that "there's going to be a new weapon. It will be ready in a year. It will be used first on Japan. If Germany is still in the war, they'll be told the second one is for them. It will revolutionize warfare. You must start work in France as soon as possible with Joliot-Curie."

  The brief encounter took place by design in the privacy of the men's room in the French delegation's villa. Goldschmidt worried that, under the circumstances, the general might not have grasped the full import of Gueron's whispered words. However, later that day, when Goldschmidt was formally introduced to de Gaulle, the general said meaningfully to him, "Thank you, Professor. I understood very well."

  Meanwhile, Los Alamos's real and most dangerous spy, Klaus Fuchs, was pursuing his activities undetected. The Russians had, with wry humor, nicknamed the Manhattan Project "Enormous" and devised code names for some of the chief associated cities: Washington, D.C, was "Carthage," New York City was "Tyre," and San Francisco was "Babylon." Their name for Fuchs was "Rest
." The bearded Igor Kurchatov, in charge of the revived Soviet fission program, wanted information that would fill in the gaps in Soviet knowledge and was driving Fuchs's agenda. Kurchatov wanted to know about gaseous diffusion as a means of separating out U-235. However, he was especially excited about information, gained through espionage, suggesting that plutonium was an alternative bomb fuel to uranium. Such prospects were, he wrote, "unusually captivating."

  Klaus Fuchs

  On first arriving in the United States with the British mission, Fuchs had spent nine months in New York working on the theory of gaseous diffusion. During evening meetings, usually in Manhattan though sometimes in Brooklyn or Queens, he gave his handler "Raymond"—the alias of the Soviet agent Harry Gold—information about it. At first Fuchs just talked. Then he began handing over notes, which, like everything he gave to Gold, he had written himself. Fuchs's information convinced Kurchatov to concentrate on gaseous diffusion for separating uranium.

  Fuchs's transfer to Los Alamos in August 1944—especially his assignment to work on implosion and plutonium—was a major breakthrough for the Soviets. For the first time, Fuchs saw the scale of the American program and understood the importance of plutonium as an alternative fuel to U-235. Somehow, the earnest young scientist, always ready to run errands for others in the beaten-up Buick he had loaned Richard Feynman, became a familiar figure around the site whose movements, despite tight security, went unremarked. In February 1945 he passed Harry Gold a detailed report on the design of the plutonium bomb. It described the problems with spontaneous fission that had led the Los Alamos teams to develop implosion. Fuchs also explained that far less plutonium than uranium was needed to make a bomb—only eleven to thirty-three pounds.