by Steve Olson
Chapter 5
THE MET LAB
WHEN SEABORG STEPPED OFF THE TRAIN IN CHICAGO, THE TEMPERATURE was 40 degrees—a shock to his California sensibilities. On the platform he read the headline of the Chicago Sun: “Tokyo Fears New Bombings; Reports Fires in Four Cities.” It was a story about the Doolittle Raid of the previous day. After Pearl Harbor, President Roosevelt demanded that his military leaders retaliate against Japan as soon as possible. Organized and led by Jimmy Doolittle, a 43-year-old MIT PhD and stunt pilot who pioneered the concept of instrument flying, 16 B-25 bombers took off from the aircraft carrier USS Hornet and dropped high explosives and incendiary bombs on Tokyo, Yokohama, and several other cities, killing more than 50 people and injuring more than 400. The bombers could not return to the Hornet and land, so most of them crashed-landed in China after their crews bailed out. Remarkably, most of the 80 crew members survived and eventually returned to the United States. The raid provided a great morale boost in the United States, demonstrating that Japan could be bombed by US forces. It also caused severe reprisals in China, where the Japanese army punished people in the villages that had aided the US airmen.
The day after his arrival, Seaborg met with Arthur Compton and some of the other people assembling at the Metallurgical Laboratory, which was the code name designed to disguise the bomb-making project in Chicago. He then had lunch at the Quadrangle Club with, among others, his Berkeley colleagues Joe Kennedy and Art Wahl. They had come to Chicago for a top-secret, two-day conference about the production of plutonium. Though no one knew whether a chain reaction was possible in the spring of 1942, the scientists and engineers in Chicago were already thinking about how to build large-scale reactors to produce plutonium—and blenching at the prospect. The fissioning uranium atoms inside a reactor would produce intense radioactivity, so the reactor’s operators would need to be shielded by thick layers of concrete and metal. Some of the elements produced by splitting uranium atoms would be radioactive gases that could not be retained in the reactor; “a stack 200 to 300 feet high might be used to carry off the gases,” Seaborg wrote in his journal that night. Fission would generate immense quantities of heat that would need to be removed from the reactor to keep it from melting or catching fire. And the reactor had to work right the first time. Once it was operated, its components would become too radioactive for anyone to enter and fix anything that had gone wrong.
Then there was the problem Seaborg had come to Chicago to solve: What was the best way to separate the plutonium from the other elements in the irradiated fuel? Several options were in the running. It might be possible to deposit plutonium from a solution onto a charged piece of metal. Maybe plutonium could be boiled away from other elements at temperatures of a couple thousand degrees. Perhaps plutonium could be added to a mixture of solvents that later could be separated, with the plutonium attaching itself to only one of the solvents.
But Seaborg was always partial to the technique he and Wahl had used in Berkeley. They would dissolve the plutonium in acid and mix chemicals into the solution that caused the plutonium to form a solid. They then would separate out this precipitate, redissolve it, and repeat the process. If this were done over and over, the plutonium should eventually become pure enough to use in a bomb.
The problem, as Seaborg readily acknowledged, was that they could perform this separation in a laboratory, but could they do it in a factory? The facilities that would be needed to separate plutonium would be huge, and chemical processes behave differently at large scales. Seaborg and his colleagues had many problems to solve in Chicago, but this was the biggest: Would they be able to scale up their tabletop chemistry by a factor of a billion?
But first Seaborg, as the leader of the Met Lab’s chemistry group, had to find enough men to run his laboratory. He began to call and write letters to all the chemists he knew, and then to all the chemists they knew. He couldn’t tell anyone what they were doing in Chicago, though he could hint at its importance. “We’re working on something that’s more important than the discovery of electricity,” he would tell potential recruits. “Come here and I’ll tell you what it is.” Once recruits signed on to the project, Seaborg loved to watch their reactions as he told them about plutonium. “Some stare in disbelief; some are dumbfounded and are glassy-eyed or open-mouthed; others become excited and pour out a torrent of questions.” Creating a new element in nuclear reactors to make atomic bombs—it sounded like science fiction.
His group set up in several rooms on the top floor of the university’s Jones Hall. They were typical college chemistry laboratories, with metal sinks, concrete benches, and noisy fume hoods. Barricades and a guard station separated the project’s chemists from the students and faculty members down the hallway. As the size of the group grew to a couple of dozen men, with an average age of about 25, they fell into a routine. They worked all day, broke for dinner, and then came back to the laboratory after dinner, with Saturday nights and Sunday afternoons off. Seaborg said he was not opposed to romantic activities so long as the night work did not suffer.
Motivation was always near at hand. “It’s hard for anyone who didn’t live through World War II to imagine the desperation and sense of impending doom that we felt,” Seaborg later wrote. In 1942, much of the US Pacific fleet lay at the bottom of Pearl Harbor, Germany controlled continental Europe, and Japan dominated East Asia. Gas and food were rationed throughout the United States, and cities practiced blackouts in case of enemy attack. German science and engineering led the world, and Seaborg and his colleagues were convinced that the Germans were far ahead in building a bomb. “Scientists like me thought less about the benefit of having the bomb than about the potentially disastrous consequences of not having it. Every day, we would follow the war’s distant events in the newspapers—German tanks rolling across North Africa, Germans advancing across Russia—events over which we had no control. We could just as easily awaken one day to read the news that Germany had unleashed a powerful new bomb. Every day, every moment, counted.”
In the summer of 1942, the leaders of the American bomb project assumed that German scientists had been working on nuclear weapons for more than three years, ever since fission was discovered in Berlin late in 1938. If the Germans had achieved a chain reaction, they could already be manufacturing and separating plutonium. On June 20, Seaborg recorded in his journal Compton’s remark that the Germans could have six atomic bombs by the end of the year. “We were fighting for survival, pure and simple.”
THE SCIENTISTS AND ENGINEERS gathered at the Met Lab in the summer of 1942 had another source of unease. They knew that their work was important to the war effort and that security was essential. They accepted the armed guards in the hallways outside their offices and the badges they had to wear to gain access to their labs. But the military’s involvement was going well beyond that.
On June 17, 1942, President Roosevelt approved a plan developed largely by Bush and Conant to have the US Army Corps of Engineers begin building large-scale plants for the separation of uranium-235 and the production of plutonium. Bush had always foreseen turning the project over to the Corps, since it had the expertise to build such plants and a budget big enough to hide the expenditures from Congress. The Corps of Engineers organizes its construction work around engineer districts, and the project’s first headquarters was at 270 Broadway in Manhattan. The project was therefore organized under the Manhattan Engineer District, and the effort to build atomic bombs eventually became known as the Manhattan Project.
Ten days after Roosevelt approved Bush’s plan to have the army build the production facilities for atomic bombs, Compton held a meeting for the group leaders of the Met Lab. He told them that their job, as outlined by Bush, was to demonstrate the feasibility of a chain reaction and then to design a pilot plant to produce plutonium. However, the Corps of Engineers would be in charge of designing and running the production plants. Furthermore, Compton said, the scientists at the lab might have to be inducted int
o the army.
The room exploded with objections. They would never be able to do good work as part of the military, the scientists said. They wouldn’t be able to meet and talk with each other in the ways that good research demanded. They would have to follow orders and do what they were told, regardless of what they thought they should do.
Already, practically before it had begun, the scientists could feel themselves losing control of the project. They had signed on because of the threat that Germany would get atomic bombs first. They thought that, with a few good engineers and construction teams, they could design, build, and operate the plutonium production facilities themselves. As usual, Szilard, who by this time had moved with Fermi, Anderson, and Zinn to Chicago to work at the Met Lab, was among the most adamant in arguing that scientists should remain in charge of the project: “Those who have originated the work on this terrible weapon,” he wrote, “and those who have materially contributed to its development have, before God and the World, the duty to see to it that it should be ready to be used at the proper time and in the proper way.”
More bad news was on the way. The Corps of Engineers works by letting contracts to industrial organizations. For the Manhattan Project, the engineering firm Stone & Webster was lined up to build the production plants. The Met Lab scientists would advise Stone & Webster on the design, but the company’s personnel, not the scientists, would be in charge of building and operating the plants.
In a famous photograph taken at the University of Chicago, Enrico Fermi and his assistant Herb Anderson are standing in the bottom left and bottom right corners, respectively. Leo Szilard is standing next to Anderson. Courtesy of Los Alamos National Laboratory.
To the Met Lab scientists, this was both insulting and dangerous. Stone & Webster had no experience or history with nuclear physics. The project could not possibly work unless it was run by experts. A big engineering firm would have “no knowledge at all of nuclear physics, and very little knowledge of the other engineering problems,” recalled Met Lab physicist Eugene Wigner, who even then was working on the design of the production reactors. Furthermore, the involvement of industry suggested the production of atomic bombs on an industrial scale. That made it seem as if the United States would keep building bombs after the war. But only a few bombs would be enough to keep Germany from using any atomic bombs it might manage to build.
Compton remained firm. He told the Met Lab scientists that the construction and operation of plutonium production plants were far beyond their experience and capabilities. They would be much more valuable as advisors than construction managers. That meeting, and subsequent ones on the same issue, ended in an impasse. The controversy would fester throughout the war and beyond.
Chapter 6
PLUTONIUM AT LAST
SHORTLY AFTER COMING TO CHICAGO, SEABORG HAD AN IDEA. AT that point, plutonium had never been made in quantities large enough even to see. Its existence had always been inferred by the radioactive signals it emitted. But the Met Lab desperately needed plutonium to study. How could the chemists, physicists, metallurgists, and engineers learn about its properties without having a sample they could hold in their hands?
In June, Seaborg and his team loaded 300 pounds of a uranium compound into plywood boxes of different sizes and shapes. Trucked to St. Louis, the boxes were wedged into the target area of a cyclotron at Washington University. On July 27 the irradiated uranium arrived back at the University of Chicago. Many of the boxes had cracked open, spilling their highly radioactive contents. Seaborg told the other chemists to wear rubber gloves and lab coats and stay as far away from the irradiated uranium as possible. But whether they were as careful as they should have been is questionable. “We were told to take precautions,” wrote Dan Koshland, one of the chemists Seaborg had recruited who later went on to become editor of Science magazine. “Almost unanimously, we young scientists discarded this advice because we believed we were in a necessary war against an evil Hitler bent on global domination. With our friends dying on the battlefield, slowing research to be extremely cautious about our own lives seemed inappropriate.”
The chemists hauled the irradiated uranium to the fourth floor of Jones Laboratory. In huge cauldrons on the outdoor balconies of the lab, trying to shield themselves behind lead plates as they worked, the chemists dissolved the uranium in ether. They then began the painstaking task of precipitating and dissolving and precipitating and dissolving the uranium, plutonium, and fission products. “We were pretty young, ranging from 20 to probably 30 years old,” one of the chemists later told an interviewer:
The whole operation was carried out in the spirit of what one might say was boisterous fun. At any one time there might be as many as eight or 10 of us shaking up the ether solutions and extracting it. At other times, as during the evaporation, there were of course fewer people involved. There was a lot of kidding and joking. By this time we had come to know each other well, we were all single, we ate lunch together, many of us had dinner together. We might even take a few minutes for a beer together. We were like a close-knit, small family.
Seaborg had hired two chemists who were experts at working with very small quantities of materials, a technique known as microchemistry. But these quantities were even smaller than those they had used before, and one of Seaborg’s hires coined the term ultramicrochemistry to describe what they were doing. Watching through microscopes, they used hypodermic needles as pipettes, operated micromanipulators to scale down their movements, and weighed their compounds by hanging them at the end of a single quartz fiber. Seaborg called it weighing invisible material with an invisible balance.
By August 20, they had succeeded in isolating a tiny pinkish speck of plutonium. “Today was the most exciting and thrilling day I have experienced since coming to the Met Lab,” Seaborg wrote that night. It was the first time an artificial element had been created in large enough quantities to see with the naked eye. That evening, at the regular Thursday meeting of the research associates, Seaborg said he “felt like passing out cigars.”
BY THAT TIME, people had been working with radiation for more than four decades, and its potential for harm was well known. Radiation kills cells by knocking electrons off atoms, and it is particularly tough on fast-dividing blood, skin, and gastrointestinal cells. Pierre and Marie Curie developed radiation burns that took months to heal, and Marie later died of radiation poisoning. Thomas Edison almost lost his eyesight after inventing the first commercial fluoroscope, which used X-rays to image bones, and his fluoroscopy assistant, Clarence Dally, had to have both arms amputated before dying, in 1904, of radiation-induced cancer.
By the 1920s, professional societies representing X-ray workers in the United States and Europe had developed standards to protect against occupational exposures. But even then experts on radiation and health were debating an issue that remains unresolved today. Is exposure to any amount of radioactivity dangerous, or is there a level that the body can tolerate without harm? In the 1920s and 1930s, the latter viewpoint prevailed. Radiation scientists generally assumed that the body could repair damage caused by low levels of radiation. This idea was embodied in the concept of a tolerance dose below which there was no danger.
The work at the Met Lab took this issue to an entirely new level. For the first time, people would be able to manufacture vast quantities of radioactive substances in nuclear reactors. These reactors would produce fission products, plutonium, and other transuranic elements that had never existed before. The people working in reactor facilities would need to be shielded from intense radiation, as would the people responsible for disposing of the reactors’ radioactive by-products. Even the people living near reactors would be exposed to unprecedented levels and types of radioactive materials emitted into the air and water; they, too, would need to be protected.
To deal with these and other health issues, Compton set up a health division in the Met Lab that had two main tasks. The first was to protect workers and the public against the ra
dioactivity generated by the project. The second was to learn more about the hazards posed by the radioactive materials. Together, these two endeavors became known as health physics, a name chosen in part to disguise the Met Lab’s activities. Health physics remains a thriving discipline today.
To protect workers, the health division adapted standards developed before the war for X-ray technicians and other radiation workers. For example, workers at the Met Lab carried dental X-ray film in their security badges. If the film was fogged when it was developed, a worker had gotten too much exposure.
But detectors had to be used to be effective. Seaborg, for example, was always adamant about protecting the health of his chemists, but they found it awkward to hold a beaker with one hand and a lead shield with the other. Instead, his team rotated people in and out of radioactive areas and drew blood from them every day to see if their white blood cell counts had dropped, which would indicate that their radiation exposures had reached dangerous levels.
Careful monitoring of the Met Lab personnel began to reveal some of the hazards of the atomic age. One time a Met Lab worker was walking by a soda machine when a portable radiation monitor she was wearing went off. When the man delivering syrup to the soda machine had arrived that morning, he discovered that he had forgotten to bring a hose from the truck. Rather than retrieving his own hose, he poked around the lab to find one he could use. Fortunately, the mistake was caught before too many people drank the plutonium-laced sodas the machine had been dispensing.
Learning more about the health effects of radiation required doing research on living organisms. Sometimes the members of the health division volunteered as guinea pigs, exposing themselves to radiation and monitoring the effects. They also did animal experiments, both at the University of Chicago and elsewhere. Once a dog being used in plutonium exposure experiments at the Met Lab escaped into the surrounding neighborhood. The residents of the stately brick mansions on Woodlawn Avenue must have wondered about the white-coated researchers chasing a probably highly radioactive dog up and down the street. Another time the chemists at the Met Lab got nervous about the radioactive wastes they were pouring down the sink. First they spiked wastewater from the lab with a strong banana oil to try to figure out where it was entering the sewer. Failing to distinguish the scent of banana from the other smells in the sewer, they tried unsuccessfully to measure the radioactivity of the sewer water as it flowed by. Finally, they opened the cesspool near the lab that collected solid material and found it to be, in the words of one chemist, “quite radioactive.” They closed it up and hoped for the best.
