Diana Preston - Before the Fallout

That afternoon the team changed the settings. Fermi was highly nervous as the last control rod—nicknamed “Zip”—was slowly withdrawn and the moment of criticality approached. He had constructed his machine in the heart of the city and was attempting something never done before. Three scientists, known as “the suicide squad,” stood by with buckets of a cadmium salt solution—a substance that sucked up neutrons—which they were ordered to throw on the pile if the nuclear reaction showed signs of getting out of control. But all went well, and an audience of forty gasped as the Geiger counters clicked and the line on the graph paper shot up as the chain reaction began. “The event was not spectacular,” Fermi wrote a decade later, “no fuses burned, no lights flashed. But to us it meant that release of atomic energy on a large scale would be only a matter of time.” After a run of twenty-eight minutes the pile was safely closed down again by reinserting the control rods. Eugene Wigner produced a bottle of Chianti in Fermi’s honor. After drinking the contents out of paper cups, those present signed their names on the bottle’s straw covering.

With hindsight, this event would be seen as the great turning point—the release of a transcendental source of energy. Laura Fermi would call it the atomic age’s only true birthday. Many would dismiss what followed as mere engineering. However, that was not how things seemed to Groves in late 1942 with his great task still ahead of him. Despite Fermi’s success, there was still no firm proof that controlled chain reactions in a nuclear pile could be used to produce plutonium on a large scale—or that a bomb using plutonium or U-235 would explode. Fermi’s experiments were based on using “slow neu­trons”—that is, neutrons that had been slowed down using a moderator, in this case graphite. In a bomb the neutrons would be “fast” because it would be technically infeasible to include a moderator.

Nevertheless, the Chicago experiment was highly encouraging. On 28 December 1942 President Roosevelt formally approved funding for industrial-scale production plants for plutonium and U-235. Groves was content for the uranium-separation plants and a small pilot plutonium-production plant to be built at Oak Ridge, where construction would start in February 1943. However, he decided not to locate the huge plutonium-producing reactor plants there. There would be practical problems over acquiring more land and ensuring sufficient power and water supplies, but, more important, he worried “about the possible danger to the surrounding population…. If because of some unknown and unanticipated factor a reactor were to explode and throw great quantities of highly radioactive materials into the atmosphere… the loss of life and the damage to health in the area might be catastrophic.”

Groves drew up a list of criteria for the plutonium site, one of which stipulated that no town of one thousand or more should be within twenty miles. Everything suggested that a location should be found in the West. For two weeks a reconnaissance party searched from Washington State to the Mexican border. The site Groves finally selected was near the small town of Hanford in Washington—a scrubby, unfertile area of sagebrush along the Columbia River, mostly used for grazing sheep. The population was small, and land values were low. In January 1943 Groves initiated what would be one of the largest land purchases of the war: more than four hundred thousand acres and space enough for the gargantuan physical and intellectual challenge ahead. Hanford would one day have 540 buildings, 600 miles of roads, 158 miles of railway track, and hire 132,000 people.

In Russia the Nazi invasion had interrupted the already very limited fission research program. Facilities and personnel were transferred to Kazan and other industrial cities beyond the Urals and scientists diverted to more urgent defense projects such as devising ways to protect ships from magnetic mines. However, in early 1942 a sharp-eyed physicist, twenty-eight-year-old Georgii Flerov, had noticed that the names of all the well-known scientists understood to have been working on atomic fission had disappeared from international academic journals. Personally and passionately convinced of the feasibility of constructing a nuclear weapon and suspicious about “dogs that did not bark,” Flerov wrote to Stalin, urging that the Soviet Union should build the uranium bomb without delay.

Flerov’s messianic enthusiasm chimed with reports that had begun arriving in Moscow a few weeks earlier from a Soviet agent in London: Anatolii Gorskii, code-named “Vadim.” These reports detailed top-level British discussions of the Maud Report. They revealed to the Russians that Britain had decided to build an atomic bomb, that it would be likely to take between two and five years, and that some of the necessary plant would be built in the United States. The source of this information was probably John Cairncross, the so-called Fifth Man of the group of spies recruited by the Soviets at Cambridge University in the 1930s and at that time the private secretary to Lord Hankey, then a minister in the war cabinet.

At first the Soviet Union was too preoccupied with holding back the invading Germans to react to the startling intelligence, but in March 1942 the government interior minister Lavrenty Beria, Stalin’s notorious police chief, ordered a thorough review of the Maud information. Eminent Soviet scientists, including Abram Joffe and Peter Kapitza, were consulted in strictest secrecy. Although Kapitza believed a nuclear bomb to be theoretically possible, he said that the Soviet Union was not ready for such a step; an atom bomb was not a weapon for the war with Germany but a matter for the future. However, others, including Igor Kurchatov, who at the outbreak of war had adopted the Roman custom of refusing to shave until the enemy was defeated and was growing ever more hirsute, were more enthusiastic. Their comments persuaded Stalin to revive the Soviet Union’s nuclear research program and, in the words of Stalin’s devoted aide Vy ache slav Molotov, “to realise the creation of an atomic bomb.” By a strange irony the Maud Report was thus the catalyst not only for the U.S. bomb program but for the Soviet one as well.

Stalin authorized the building of a new laboratory to take charge of all nuclear research and placed it under the scientific direction of Igor Kurchatov. Work began in March 1943—just over a month after German troops surrendered at Stalingrad after a Soviet counteroffensive code-named “Uran”—meaning “Uranus” or “uranium”—which was, perhaps, not a coincidence.

IN BRITAIN and the United States the overriding worry was how far the Germans had progressed. For some, every scientific advance by Allied scientists was double-edged. As Leo Szilard pointed out tirelessly, anything the Allies did, the Nazis could do too. On 22 June 1942 a worried Arthur Compton wrote from Chicago to Vannevar Bush that “we have just recognised how… a small heavy-water plant can quickly supply material for a high power plant for producing [fissionable material]. If the Germans know what we know—and we dare not discount their knowledge—they should be dropping fission bombs on us in 1943, a year before our bombs are planned to be ready.”

The British were increasingly anxious about intelligence reports that the Nazis were stepping up production of heavy water at the Norsk-Hydro plant at Vemork, near Rjukan in occupied Norway. They knew that Jomar Brun, a member of the Norwegian resistance and an engineer at the plant, was feeding castor oil into the production process to ensure frequent breakdowns. However, realizing that local sabotage could not succeed forever, Churchill’s war cabinet ordered the plant to be destroyed in an operation code-named “Freshman.”