Eugene Wigner came to the project's rescue. Fermi had found
Wigner's team designed a 28- by 36-foot graphite cylinder lying on its side and penetrated through its entire length horizontally by more than a thousand aluminum tubes. Two hundred tons of uranium slugs the size of rolls of quarters would fill these tubes. Chain-reacting within 1,200 tons of graphite, the uranium would generate 250,000 kilowatts of heat; cooling water pumped through the aluminum tubes around the uranium slugs at the rate of 75,000 gallons per minute would dissipate that heat. The slugs would not go naked into the torrent; Wigner intended that they also should be separately sheathed in aluminum — canned. When they had burned long enough — 100 days — to transmute about 1 atom in every 4,000 into plutonium the irradiated slugs could be pushed out the back of the pile simply by loading fresh slugs in at the front. The hot slugs would fall into a deep pool of pure water that would safely confine their intense but short-lived fission-product radioactivity. After 60 days they could be fished out and carted off for chemical separation.
The Wigner design was elegantly simple. Greenewalt saw engineering problems — in particular the question whether corrosion of the aluminum tubes would block the flow of cooling water — and studied helium and water side by side until the middle of February. Corrosion studies were promising. “With water of high purity,” writes Arthur Compton, “the evidence indicated that no serious difficulties from this source should arise.” Greenewalt opted then for water cooling. Wigner, whom Leo Szilard calls “the conscience of the Project from its early beginnings to its very end,” who worried constantly about German progress, wondered angrily why it had taken Du Pont three months to see the value of a system he and his group had judged superior in the summer of 1942.
With that basic decision construction could begin at Hanford. Three production piles would go up at six-mile intervals along the Columbia River, two upstream and one downstream of its ninety-degree bend. Ten miles south, screened behind Gable Mountain, Du Pont would build four chemical-separation plants paired at two sites. The former town of Han-ford would become a central construction camp serving all five construction areas.
The work proceeded slowly, dogged by recruiting problems. The nation at war had moved beyond full employment to severe labor shortages and men and women willing to camp out on godforsaken scrubland far from any major city were hard to find. Frequent sandstorms plagued the area, writes Leona Woods, now Leona Marshall after marrying fellow physicist John Marshall of Fermi's staff. “Local storms were caused by tearing up the desert floor for roads, and construction sites were suffocating. Wind-blown sand covered faces, hair, and hands and got into eyes and teeth… After each storm, the number of people quitting might be as much as twice the average. When the storms were at their worst, buses and other traffic came to a stop until the roads were visible through the grey-black clouds of dust.” Stoics who stayed on called the dust “termination powder.”
“The most essential thing to bring with you is a padlock,” a project recruiting pamphlet ominously announced. “The next important things are towels, coat hangers and a thermos bottle. Don't bring cameras or guns.” Hanford, says Marshall, “was a tough town. There was nothing to do after work except fight, with the result that occasionally bodies were found in garbage cans the next morning.” Du Pont built saloons with windows hinged for easy tear-gas lobbing. Eventually some 5,000 construction workers struggled in the desert dust and Du Pont built more than two hundred barracks to house them. Meat rationing stopped at the edge of the reservation; there were no meatless Tuesdays in the vast Hanford mess halls, a significant enticement for recruiting. The gray coyotes of the region fed sleek in turn on rabbits killed by cars and trucks driving the new reservation roads.
By August 1943 work had begun on the water-treatment plants for the three piles, capacity sufficient to supply a city of one million people. Du Pont released pile-design drawings in Wilmington, Delaware, on October 4 and the company's engineers staked out the first pile, 100-B, beside the Columbia on October 10. After excavating, reports an official history, “work gangs began to lay the first of 390 tons of structural steel, 17,400 cubic yards of concrete, 50,000 concrete blocks, and 71,000 concrete bricks that went into the pile buildings. Starting with the foundations for the pile and the deep water basins behind it where the irradiated slugs would be collected after discharge, the work crews were well above ground by the end of the year.” The forty-foot windowless concrete monolith they were building was hollow, however: installation of B pile would not begin until February 1944.
“There was a large change of scale from the Chicago to the Hanford piles,” Laura Fermi remarks. “As Fermi would have put it, they were different animals.” So also were Ernest Lawrence's behemoth mass spectrometers and John Dunning's gaseous-diffusion factory with its 5 million barrier tubes. The mighty scale of the works at Clinton and Hanford is a measure of the desperation of the United States to protect itself from the most serious potential threat to its sovereignty it had yet confronted — even though that threat, of a German atomic bomb, proved to be an image in a darkened mirror. It is also a measure of the sheer recalcitrance of heavy-metal isotopes. Niels Bohr had insisted in 1939 that U235 could be separated from U238 only by turning the country into a gigantic factory. “Years later,” writes Edward Teller, “when Bohr came to Los Alamos, I was prepared to say, ‘You see…’ But before I could open my mouth, he said, ‘You see, I told you it couldn't be done without turning the whole country into a factory. You have done just that.’”
The monumental scale reveals another desperation as well: how ambitiously the nation was moving to claim the prize. And to deny it to others, even to the British until Winston Churchill turned Franklin Roosevelt's head at the conference in Quebec in August 1943, where Operation Overlord, the 1944 invasion of Europe across the beaches of Normandy, was planned. Before then, in June, Groves had demonstrated this last desperation at its most overweening: he proposed to the Military Policy Committee that the United States attempt to acquire total control of all the world's known supplies of uranium ore. When the Union Miniere refused to reopen its flooded Shinkolobwe Mine in the Belgian Congo, Groves had to turn to the British, who owned a significant minority interest in the Belgian firm, for help; after Quebec the partnership evolved into an agreement between the two nations known as the Combined Development Trust to search out world supplies. That uranium is common in the crust of the earth to the extent of millions of tons Groves may not have known. In 1943, when the element in useful concentrations was thought to be rare, the general, acting on behalf of the nation to which he gave unquestioning devotion, exercised himself to hoard for his country's exclusive use every last pound. He might as well have tried to hoard the sea.
Work toward an atomic bomb had begun in the USSR in 1939. A thirty-six-year-old nuclear physicist, Igor Kurchatov, the head of a major laboratory since his late twenties, alerted his government then to the possible military significance of nuclear fission. Kurchatov suspected that fission research might be under way already in Nazi Germany. Soviet physicists realized in 1940 that the United States must also be pursuing a program when the names of prominent physicists, chemists, metallurgists and mathematicians disappeared from international journals: secrecy itself gave the secret away.
The German invasion of the USSR in June 1941 temporarily ended what had hardly been begun. “The advance of the enemy turned everyone's thoughts and energies to one single job,” writes Academician Igor Golovin, a colleague of Kurchatov and his biographer: “to halt the invasion. Laboratories were deserted. Equipment, instruments and books were packed up, and valuable records shipped east for safety.” The invasion rearranged research priorities. Radar now took first place, naval mine detection second, atomic bombs a poor third. Kurchatov moved to Kazan, four hundred miles east of Moscow beyond Gorky, to study defenses against naval mines.
In Kazan at the end of 1941 he heard from George Flerov, one of the two young physicists in his Moscow laboratory who had discovered the spontaneous fission of uranium in 1940 and reported their discovery in a cable to the
In recent years a new possibility — nuclear energy — has been discovered. Theoretical calculations show that, if a contemporary bomb can for example destroy a whole city block, an atomic bomb, even of small dimensions, if it can be realized, can easily annihilate a great capital city having a few million inhabitants.
Thus recalled to their earlier work, Flerov challenged Kurchatov as he had already in a similar letter challenged the State Defense Committee that “no time must be lost in making a uranium bomb.” The first requirement was fast-neutron research, he wrote. The MAUD Report had only just made that necessity clear to the United States.
Kurchatov disagreed. Research toward a uranium weapon seemed too far removed from the immediate
