The Apocalypse Factory

by Steve Olson

  On Monday, March 3, 1941, Seaborg and his colleague Emilio Segrè transported the irradiated uranium from the cyclotron to Gilman Hall, where the physics department had made them an extraction apparatus that they could operate by remote control. They dissolved the irradiated uranium in two liters of ether and separated out the remaining uranium, leaving behind neptunium, their new element (which was continuously being created by the decay of neptunium), and lots of fission products. They placed this solution in a tube that they carried to a nearby laboratory with a large centrifuge. There they spun the tube to separate element 94 from the lighter fission products. Six times they repeated this procedure, each time getting a purer sample of their new element. Finally they poured the purified sample into a platinum dish about the size of a dime. They labeled it Sample A and stored the sample in a cigar box.

  When Room 307 of Gilman Hall was dedicated as a national landmark in 1966, Art Wahl and Glenn Seaborg posed with the sample of plutonium that they produced there in March 1941.Courtesy of the US National Archives and Records Administration.

  The crucial test came on March 28. Seaborg and his colleagues placed their sample of element 94 in the path of neutrons being generated by the cyclotron. Almost immediately a detector began picking up the unmistakable signals of fission. More testing revealed that the new element generated even more neutrons when it fissioned than did uranium-235. That meant it could produce even more powerful atomic bombs.

  It took a while for the implications of this discovery to sink in, but they were profound. Seaborg and his colleagues had discovered a way to convert the common isotope of uranium, which could not support a chain reaction, into a previously unknown element that could. In a stroke, they had multiplied by a hundredfold the amount of energy that could be extracted from uranium. Furthermore, they had shown that they could use chemistry to separate this new element from other elements. They did not need to rely on the small difference in weight between uranium-235 and uranium-238 to produce bomb-making material. They had found a new and much easier way to make atomic bombs.

  BY THE SPRING OF 1941, Seaborg and his colleagues were no longer talking about their discoveries in public—or even with most other scientists. As soon as scientists in the United States realized that certain radioactive substances might be used to build atomic bombs, they quit publishing their results in the scientific literature, afraid that anything they said could help German scientists develop a bomb. But physicists in Germany immediately saw what was happening and drew the obvious conclusion: American physicists must be working on nuclear weapons. Physicists on both sides of the conflict concluded that they were in a race to see which country could build atomic bombs first.

  To maintain secrecy, Seaborg and his colleagues initially referred to their new element simply as 94, for the number of protons it contained. But they knew it would eventually need a real name. At first, they mistakenly thought that it would be the heaviest element ever discovered and considered such names as extremium and ultimium. “Fortunately, we were spared the inevitable embarrassment that one courts when proclaiming a discovery to be the ultimate in any field,” Seaborg later reflected.

  They decided to follow precedent. The planet Pluto had been discovered in 1930, when Seaborg was an undergraduate at UCLA. After Uranus and Neptune had been honored, Pluto seemed the logical next step. Seaborg’s group briefly considered the name plutium, but they thought that plutonium sounded better. Much was made in later years about Pluto being the god of the underworld, but Seaborg later professed to be unaware of the connotation. “I was unfamiliar with the god or why the planet was named for him,” he said. “We were simply following the planetary precedent.”

  * As is usually the case in science, Seaborg worked with several collaborators. Labeling him the “discoverer” of element 94 requires a judgment call about the extent to which he was responsible for the direction of the research.

  Chapter 4

  THE DECISION

  DESPITE THE SECRECY SURROUNDING PLUTONIUM, WORD OF SEABORG’S achievement spread quickly through the small network of scientists and policymakers who were thinking about atomic bombs. Almost immediately, they saw something that seemed too fortuitous to be true.

  The Berkeley scientists had discovered a way to create a bomb-making material—plutonium-239—by bombarding uranium-238 with neutrons. But neutrons were hard to generate in quantity: cyclotrons could never make enough to produce atomic bombs.

  However, Fermi and Szilard, at Columbia University, were working on a device—a nuclear reactor—that could generate plenty of neutrons beyond those needed to keep a chain reaction going. Furthermore, the isotope that needed to be bombarded with neutrons, uranium-238, was right there in the reactor’s uranium ore! A nuclear reactor would make plutonium simply by operating. It was like driving a car that created more gasoline the farther it went.

  Meanwhile, Seaborg had shown that plutonium could be separated from irradiated uranium using conventional chemical processes. If all these processes were combined, a fuel for atomic bombs could be made just with nuclear reactors and chemical processing plants.

  GOVERNMENT OFFICIALS HAD KNOWN almost since the discovery of fission that atomic bombs might be possible if enough uranium-235 could be separated from natural uranium ore. But they did not do much to follow up on the possibility until Seaborg and his colleagues discovered plutonium in the spring of 1941, and one man was at the forefront of that change. Vannevar Bush was, in the estimation of biographer G. Pascal Zachary, the “engineer of the American century.” Educated at Tufts College and the Massachusetts Institute of Technology, Bush spent the first 20 years of his professional life doing research, teaching, and rising through the ranks of the MIT administration. Known as Van to his friends—he considered his first name “a nuisance”—he developed techniques for detecting submarines during World War I, built a forerunner of today’s electronic computers, and cofounded the company now known as Raytheon. But he wanted to do more than invent. He wanted inventions to be used.

  In 1939, Bush moved from Massachusetts to Washington, DC, to become president of the Carnegie Institution of Washington. From his new office just eight blocks north of the White House, Bush was ready to do what he thought he could do best: shepherding inventions from America’s labs into the federal government, and especially into the military. But he also knew that “you couldn’t get anything done in that damn town unless you organized under the wing of the President.” Through a Carnegie trustee who was Franklin Roosevelt’s uncle, he arranged a meeting with the president on June 12, 1940. There he gave Roosevelt a memo proposing a National Defense Research Committee that would “correlate and support scientific research on mechanisms and devices for warfare.” After less than 15 minutes of discussion, Roosevelt approved the plan. Bush would remain independent of government and continue to be paid through the Carnegie Institution, but he now had a direct line to the president and funds from the White House budget to prepare new technologies for the military.

  Many technologies were on the verge of making wartime contributions—radar, new kinds of submarine detectors, electronic devices to set off explosives as they neared their targets. But one loomed above the rest—what Bush called “this uranium headache.” As he told a friend in the spring of 1941, “I wish that the physicist who fished uranium in the first place had waited a few years before he sprung this particular thing on an unstable world.” Rumors were emerging from Europe that German physicists were working on fission, and Bush acknowledged that he was “scared to death” of a Nazi bomb. But isolating enough uranium-235 to make a bomb looked like it would take years, if it could be done at all, and the news about plutonium was just starting to emerge from Berkeley.

  As would happen often in the next few years, Bush turned for advice to a committee. The National Academy of Sciences, chartered by President Lincoln in 1863 during the darkest days of the Civil War, was mostly an honorific society for esteemed scientists. But its Act of Incorporation
also states that “the Academy shall, whenever called upon by any department of the Government, investigate, examine, experiment, and report upon any subject of science or art.” In the spring of 1941, Bush gave the Academy the most important assignment it had ever received: to review the possible military uses of fission.

  The Academy created a six-member committee, chaired by Arthur Compton, dean of science at the University of Chicago, to conduct its review. In 1927, Compton had won a Nobel Prize for his discovery of what is known as the Compton effect, which demonstrated that light can behave like a particle as well as a wave. He was also an intensely religious man: “God can have no quarrel with a religion which postulates a God to whom men are as His children,” he once told a reporter from Time magazine, which put him on the cover of its January 13, 1936, edition. Yet he had no qualms about leading a committee charged with investigating the engines of war: “As long as I am convinced, as I am, that there are values worth more to me than my own life, I cannot in sincerity argue that it is wrong to run the risk of death or to inflict death if necessary in the defense of those values.”

  The Academy committee, which included Berkeley’s Ernest Lawrence, submitted its report on May 17. The committee noted that separating large quantities of uranium-235 from uranium ore would probably take at least three to five years, even under optimistic assumptions. But there was another possibility, the committee pointed out. If a nuclear reactor could be built, and if plutonium could be chemically extracted from the irradiated uranium such a reactor would produce, bombs using plutonium could be built “within twelve months from the time of the first fission chain reaction,” according to the committee. It recommended “strongly intensified” research on both isotope separation and plutonium production. “Within a half dozen years the consequences of such investigations may be crucial in determining the nation’s military position.”

  Arthur Compton (left) was chair of the National Academy of Sciences committee that advised Vannevar Bush (right) about the prospects for developing atomic bombs. Corbis via Getty Images.

  After a few days of reflection, Bush found himself unsatisfied with the report. The pressure to do something more than study the problem was growing. Bush had been receiving secret information from a committee in England that also had been examining fission. It had concluded that an atomic bomb could be built within three years and that, as it stated in its own report, “the first side to perfect this scheme will gain a decisive and crushing victory.” But Britain, holding out against the Nazis, with its factories straining to produce armaments, could not hope to undertake a massive bomb project. American scientists should take the lead, their British counterparts urged.

  Bush was also beginning to realize how important atomic bombs would be after the war, regardless of whether they were used during it. The British nuclear program was well ahead of the American program. If the United States did not accelerate its work on fission, Britain could emerge from the war with the lead in nuclear technologies. Furthermore, the first country to build atomic bombs would gain tremendous political power—whether that country was the United States, Britain, Germany, or the Soviet Union. “I still shudder when I think what sort of a world it would have been if we had quit, and Russia had completed the job,” Bush later wrote.

  He asked the Academy committee to look at the issue again, but this time with additional members who could provide an engineering perspective on the project. The committee delivered its second report to Bush on July 11. That report was as skeptical as the first about the prospects for separating uranium-235, stating that the technologies being studied showed “little, if any, more promise of immediate or even early application than at the time of the previous report.” But the committee, and especially Lawrence, was increasingly optimistic about the prospects for plutonium. “If large amounts of element 94 were available it is likely that a chain reaction with fast neutrons could be produced,” Lawrence wrote in an appendix to the report. “In such a reaction the energy would be released at an explosive rate which might be described as a ‘super bomb.’”

  If isotope separation were the only route to a bomb, the Manhattan Project might never have happened. But Seaborg’s discovery of plutonium in early 1941 provided a second option, and by that summer this second option was a powerful inducement. Even if isotope separation failed, plutonium production could work. And the availability of two routes to a bomb meant that Germany, which certainly had the scientific talent to discover plutonium, could get there two ways as well.

  The next time Bush met with Roosevelt to discuss fission research was on October 9, 1941. By this time, Bush’s mind was made up: “I knew that the effort would be expensive, that it might seriously interfere with other war work. But the overriding consideration was this: I had great respect for German science. If a bomb were possible, if it turned out to have enormous power, the result in the hands of Hitler might enable him to enslave the world. It was essential to get there first, if an all-out American effort could accomplish the difficult task.” At the meeting with the president, Bush described the amount of material needed for a bomb, the cost of production plants, and how much time would be needed to build a weapon. He could not guarantee that the effort would be successful, but the science was promising and the implications of success profound. Again, Roosevelt quickly approved the plan—a greatly expanded research project was clearly warranted. But any steps toward production of bomb-making materials or of a bomb itself would require further approval from the three men at the meeting—Bush, Roosevelt, and vice president Henry Wallace—plus two others who would make pivotal decisions about atomic strategy throughout the war: Secretary of War Henry Stimson and Army Chief of Staff George Marshall.

  Even with Roosevelt’s okay, Bush wanted the blessing of his scientific advisors before initiating a massive research program. The same day he met with Roosevelt, he asked the National Academy of Sciences committee for a third assessment of fission. This report, delivered on November 6, 1941, was much less equivocal than the earlier two. “Within a few years the use of explosive fission may become the predominant factor in military action,” the report stated. Regardless of whether atomic bombs used uranium-235 or plutonium, they would be weapons “of superlatively destructive power,” the committee wrote. “This seems to be as sure as any untried prediction based upon theory and experiment can be.”

  NOW THAT BUSH HAD the president’s support, he moved quickly to reorganize the government’s fission program. He put Ernest Lawrence and Harold Urey, a physicist at Columbia University, in charge of overseeing the work on isotope separation—the former because he was convinced he could convert his cyclotrons into devices for doing the job. A planning board under the direction of Eger Murphree, a chemical engineer at the Standard Oil Development Company, started considering how to scale up laboratory-sized experiments to industrial-sized processes. And he put the University of Chicago’s Arthur Compton, the chair of the National Academy of Sciences committee, in charge of research on the chain reaction and the production of plutonium.

  At this point, the use of plutonium to construct an atomic bomb was still a long shot. Seaborg had discovered it less than a year earlier, and its basic properties and chemistry remained murky. Most people did not even know that a new element had been discovered, since Seaborg and his colleagues had kept their work secret. But Compton, after being proselytized by Lawrence, was a convert to plutonium. On Saturday, December 6, 1941, he met Bush and Bush’s second-in-command at the National Defense Research Committee, Harvard University president James Conant, for lunch at the old Cosmos Club on Lafayette Square, just north of the White House. There the conversation turned to plutonium. Conant, an expert on acids and bases who had worked on the development of poison gases during World War I, remained highly skeptical about plutonium’s prospects. Almost nothing was known about its chemistry, he pointed out. Who knew if it could be extracted from irradiated uranium? And doing so would be extremely difficult because of the intense
radioactivity of the accompanying fission products.

  Compton responded, “Seaborg tells me that within six months from the time the plutonium is formed he can have it available for use in the bomb.”

  Conant replied, “Glenn Seaborg is a very competent young chemist, but he isn’t that good.”

  The next morning—Sunday, December 7, 1941—350 Japanese aircraft launched from six aircraft carriers attacked the US naval base at Pearl Harbor. More than 2,400 Americans were killed, and another 1,100 were wounded. All eight battleships in the harbor were damaged and four were sunk, along with several smaller ships. The next day the United States declared war on Japan; three days later Hitler declared war on the United States. America’s isolation from the rest of the world had ended.

  THE NEXT MONTH, Seaborg was relieved of all his teaching responsibilities at Berkeley so he could work full-time on plutonium. The university had received $400,000 for bomb-related work, though much of that went to adapting Lawrence’s cyclotron to separate uranium isotopes. Still, Seaborg now had the resources to begin addressing a long list of questions he had about plutonium: Can it fission without being hit by a neutron? How long does it take to decay? Are there better ways to separate it from other elements?

  In March 1942, Compton’s assistant came to Berkeley to tell Seaborg that he should plan on moving to Chicago. Compton had decided that all the work on plutonium should be concentrated in a single place, and he had chosen his own university as the location. Seaborg boarded the train for Chicago on April 17, 1942. He arrived two days later, at 9:30 in the morning. It was his thirtieth birthday.