The Plutonium Files (7 page)

But Ernest Lawrence countered that the project should be established in Berkeley. After all, it was Glenn Seaborg, one of Lawrence’s young colleagues, who had isolated plutonium (and would marry Lawrence’s secretary in a few short months). Besides, there was something undeniably magical about Berkeley. The classrooms and laboratories were filled with Nobel laureates and future Nobel laureates, and scientific discoveries seemed to occur as effortlessly as the ripe apricots that dropped from trees in nearby orchards.

Compton, himself a Nobel Prize winner, already had his mind made up. He insisted that the project should be housed at the University of Chicago for a number of reasons: The school’s administrators had promised full cooperation; housing was adequate; more scientists were available
in the Midwest than on the eastern or western seaboards; and the city was not as vulnerable to military attack as the coastal cities.

Lawrence objected. “You’ll never get the chain reaction going here.
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The whole tempo of the University of Chicago is too slow,” he told Compton.

“We’ll have the chain reaction going here by the end of the year,” Compton retorted.

“I’ll bet you a thousand dollars you won’t,” responded Lawrence.

When Compton accepted the bet, Lawrence dropped the stakes to a five-cent cigar. As soon as the scientists left, Compton climbed out of bed and called Enrico Fermi—the man upon whose shoulders the success of the whole plutonium project rested. Everything would flow from his chain-reacting pile, if only he would agree to move from New York. Fermi was a congenial man and eager to do his part. Reluctantly he agreed to make the move.

“The project for producing plutonium, as yet unseen even under a microscope, using a nuclear reactor that was still imaginary, and of fashioning this plutonium into bombs whose explosiveness had never been tested, was now ready to go,” Compton wrote in his memoirs.
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The coordinated effort was given the code name of the “Metallurgical Project.” Eventually the research would be spread out among some seventy groups located throughout the country, but the most critical work would be done at the University of Chicago, in a group of buildings that came to be known simply as the Met Lab.

Within a matter of weeks, the scientists began arriving. Compton’s wife, Betty, found rooms in a friend’s home for Enrico and Laura Fermi and their two children. Fermi’s two assistants shared a room in Comp-ton’s house. On a racket court under the West Stands of Stagg Field, Fermi’s men began building a series of piles that were far below the size needed for a chain reaction but would help them better understand the behavior of neutrons.

Compton also persuaded Glenn Seaborg to move his research from Berkeley to the Met Lab. Seaborg and a colleague, Isadore Perlman, arrived in Chicago on April 19, 1942—Seaborg’s thirtieth birthday—following a two-day train trip aboard the
City of San Francisco.
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As the two scientists left the station, they scanned the Chicago newspapers: Tokyo was being bombed by Allied troops and the flimsy Japanese homes were going up in flames.

In a few short months an extraordinary collection of scientists was
working at the Met Lab. They would be eclipsed in brilliance only by those eventually assembled at Los Alamos. They included Eugene Wigner, a future Nobelist known for his almost painful politeness; James Franck, a highly respected German physicist and a 1925 Nobel Prize winner; and, of course, Leo Szilard, who roamed from lab to lab, offering advice and opinions to anyone who would listen. One scientist, distracted by Szilard’s talk, suggested putting him in a state of suspended animation and then reviving him for two minutes each year. “He could give us enough ideas to keep us busy for the rest of the year.
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For two minutes he’d be fantastic, but how marvelous life in the lab would be for the rest of the year.”

Compton also asked J. Robert Oppenheimer to take over the theoretical studies necessary to construct the actual bomb. He had quizzed Oppenheimer about his Communist connections, but the scientist assured him those days were over. “I’m cutting off all my Communist connections,” Compton quoted him as saying.
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Oppenheimer assembled a group of scientists in Berkeley whom he called “the luminaries” to help him with his theoretical work. Among them were Edward Teller, Hans Bethe, Robert Serber, and John Manley.

Before Glenn Seaborg’s chemists began their laboratory experiments, they spent two days with the project’s top leaders discussing how to go about studying plutonium. Met Lab officials decided that plutonium research was to have a “special category of secrecy,” Seaborg wrote in his journal, and information about it would be strictly limited to a small circle of people within the lab itself.
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To further ensure its secrecy, the leaders decided a new terminology was needed. He wrote:

The group came up with new code words for those elements derived from the last digit in the atomic number and the last digit in the atomic weight for each isotope. Thus plutonium-239, with an atomic number of 94 and an atomic weight of 239, became known for the duration of the
bomb project as 49. Soon another code name for plutonium emerged: the product.

The Chicago chemists worked with amounts of plutonium even smaller than those available to the Los Alamos chemists a year and a half later.
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Since the machine shops were already swamped with requests from the physicists, Seaborg’s men fashioned their own tiny instruments. They made balances from quartz fibers to weigh their precious millionths of a gram. Miniature pans were created from very thin platinum foil cut and shaped under the microscope. To protect the delicate instruments from air currents, they surrounded them with small cases constructed from wood and glass.

While the chemists were making their instruments, five kilograms, or about eleven pounds, of uranyl nitrate hexahydrate was being bombarded with neutrons in Berkeley. From those eleven pounds, the Berkeley group extracted one microgram of plutonium, or one-millionth of a gram.
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The precious microgram was forwarded to Chicago. Since the sample was too small to be seen with the naked eye, radiation counters were used to determine its presence. The Met Lab then turned to Washington University in St. Louis for additional help. The St. Louis cyclotron had a more powerful beam than the one at the Rad Lab, and by early August it had produced 50 micrograms of plutonium, a collective amount that was about one-tenth the size of a grain of salt.
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To make the micrograms of plutonium, the St. Louis cyclotron crew worked around the clock. It was hot, dirty work, and it gave Louis Hempelmann, one of the crew members, a lifelong appreciation for im-ponderably small amounts of plutonium. Hempelmann had begun helping out on the cyclotron soon after returning to St. Louis.
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He also had established a clinic where cancer patients were treated with radio-phosphorous made in the cyclotron. Hempelmann injected the radioactive material into the veins of patients two to three times a week. He soon grew uneasy when some of the patients developed dangerously low blood counts and even hemorrhages. While he was convinced that radio-phosphorous was still a valuable tool, he nevertheless warned doctors in a scientific paper to monitor blood counts carefully so that treatment could be halted before “irreversible toxic effects on the bone marrow are produced.”
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By August 20, 1942, Seaborg’s microchemists had isolated their first visible speck of plutonium. It was pink in color. Wrote Seaborg, “It is the first time that element 94 (or any synthetic element, for that matter) has been beheld by the eye of man.
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I’m sure my feelings were akin to those
of a new father who has been engrossed in the development of his offspring since conception.” A holiday spirit soon enveloped the Met Lab. One of the team brought in flood lamps and photographed everything in sight.

The chemists’ elation turned to wrenching disappointment five days later when Isadore Perlman went to his lab one morning to work with his microscopic allotment of plutonium and found the contents spilled on a Sunday edition of the
Chicago Tribune.
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Someone who was concerned about radiation apparently had surrounded the beaker with lead bricks, one of which had fallen over and smashed the glass. Perlman placed the newspaper into a large dish and poured nitric acid over it. Once the Sunday paper had been dissolved, he could retrieve the plutonium through a chemical process.

The chemists soon discovered that plutonium was an “absolutely crazy” metal.
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Small amounts undergo spontaneous combustion in air; therefore, it must be handled in an atmosphere devoid of oxygen. Depending on its chemical compound, it can be blue, green, purple, yellow-brown, red, or pink. “Plutonium is so unusual as to approach the unbelievable,” Seaborg once observed:

No one who held plutonium ever forgot its seductive warmth. Leona Marshall Libby, one of the few female scientists at the Met Lab, said it felt like a “live rabbit.” But Arthur Compton thought it was much hotter.
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“I held in my hand a heavy lump of plutonium, gold-plated to protect me from the alpha particles.
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Its temperature was so high from its own radioactivity that it almost burned my fingers.”

Through the summer and fall of 1942, while Seaborg’s team continued their plutonium research, Fermi’s group continued its work on the chain reaction under the West Stands of Stagg Field. A towering pile of graphite blocks embedded with uranium was erected. Flat on top and
bulging at the sides, the edifice resembled a huge crushed bowling ball. On December 2 Fermi was ready to conduct his first test to see if the pile would actually sustain a chain reaction. It was cold in Chicago that day, about ten degrees above zero. Gas rationing had begun the day before, and the streetcars and elevated trains were jammed.

Threaded down through the pile were cadmium rods that absorbed neutrons and would be used to control the reaction. As Fermi ordered one rod after another removed, the clickety-clack of the neutron counter soon became a roar. When the pile had achieved a sustained reaction for a few minutes, Fermi ordered the control rods reinserted. As the counters subsided, the Met Lab scientists stood around in dazed silence. A bottle of Chianti in a brown paper bag was presented to Fermi. One of the greatest barriers to building a successful bomb had just been hurdled. The unflappable Fermi later said operating a pile was as easy as driving a car.

With the successful operation of Fermi’s pile, the stage was set to build a pilot plant where grams of plutonium could be produced.
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Less than three months later, construction began on a graphite reactor, code-named the X-10 plant, at the Clinton Engineer Works in Oak Ridge, Tennessee. The Clinton Engineer Works, which subsequently became the official headquarters of the Manhattan Project, was a 56,000-acre tract of land located in the foothills of the Smoky Mountains, ancient hills covered with forests and teeming with deer. Several vast factories where uranium-235 would be produced also were located in the rolling hills and valleys. The bomb builders, still unsure whether enough uranium or plutonium could be produced to make a weapon, were hedging their bets and pursuing several ways to produce enriched uranium, as well as plutonium.

The construction on the Tennessee reactor was still in its initial stages when a decision was made to build a full-scale plutonium facility in an even more isolated region. A huge windswept chunk of land in eastern Washington state near the small town of Hanford was selected. This site became known as the Hanford Engineer Works. There the chemical separation methods that Seaborg’s team developed in Chicago would be scaled up a billionfold.

In the summer of 1942, when it looked as if Enrico Fermi’s pile would actually work, the physicists began to worry about their own safety. The scientists realized that the crude nuclear reactor would be a source of copious amounts of radiation. Fermi’s pile would not only create the highly desirable plutonium, it would also create many different radioactive fission products from the middle of the Periodic Table. Extracting plutonium from this radioactive stew would be an extremely hazardous undertaking.

The physicists, Arthur Compton wrote in his memoirs, “knew what had happened to the early experimenters with radioactive materials.
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Not many of them had lived very long. They were themselves to work with materials millions of times more active than those of these earlier experimenters. What was their own life expectancy?” Compton decided there was only one thing to do: “We must bring to Chicago the most competent men we could find in the field of the physiological effects of ionizing radiations.”

Compton put out feelers to various scientists and medical doctors. Several advised him that Robert Stone was the man for the job. As a member of the National Cancer Advisory Council, Compton knew of Stone’s experimental use of neutrons for cancer treatment. Although the neutron experiment could hardly be considered a success, Compton nevertheless was impressed by Stone’s work at the Rad Lab and invited him to come to Chicago and take over the Met Lab’s new Health Division, which would be on an equal footing with the physics, chemistry, and
engineering divisions. Stone would have a seat at the table with Comp-ton, Fermi, Seaborg, and the other members of the innermost sanctum. “Stone’s exceptional qualification for this work on which the very lives of our workers depended was evident,” Compton wrote.
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