The Plutonium Files (6 page)

Friedell helped Stone with his neutron experiment and treated a few of his patients. With John Lawrence and other doctors, he also administered radioactive phosphorous and radioactive strontium to cancer patients.
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The radiophosphorous seemed especially effective in the treatment of breast cancer, Friedell recalled.
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But the radiostrontium, which behaves like calcium in the body, was a failure. Joseph Hamilton, in a letter written years later, said one of Friedell’s patients had almost died from too much radiation after he gave her a small amount of radioactive strontium.
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When Friedell was asked about Hamilton’s remarks, he said Hamilton was confused and must have been talking about radioactive phosphorous.
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But in an interview with fellow scientist J. Newell Stan-nard more than a decade earlier, Friedell said, “I was assigned a project very early working on radiostrontium.
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In fact I did some terrible things in my day. I took radiostrontium, and I was going to cure some tumors because it was going into bone, bone tumors. I got some into the bone (tumors), but I also got a hell of a lot into normal bone, too.”

While Hymer Friedell was doing his apprenticeship, Louis Hempelmann was finishing his residency in Boston, Massachusetts. One day he got an inquiry from a medical colleague back home in St. Louis. Washington University was building its own cyclotron; would Hempelmann
be interested in treating cancer patients with the radioactive materials created by the machine?

Hempelmann was intrigued by the offer. Washington University was his alma mater and St. Louis was his hometown.
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He had received his undergraduate degree in 1934 and his medical degree in 1938 from the university. He also had many friends and well-established acquaintances in St. Louis. His wife, Elinor Wickham Pulitzer, was the daughter of Joseph Pulitzer, publisher of the
St. Louis Post-Dispatch,
for whom the Pulitzer Prizes are named.

The idea of returning to St. Louis was attractive, but Hempelmann had absolutely no experience with cyclotrons or radiation therapy. So he decided to get a fellowship and find out more. He spent three months working in St. Louis and then struck out for the Rad Lab where all the breakthroughs were being reported and little, if anything, was being said of the failures.

Like Hymer Friedell, Hempelmann worked with Robert Stone and John Lawrence. Hempelmann was modest and unassuming and probably said little as he made the medical rounds in San Francisco or crossed the bay to Berkeley where the patients were being bombarded with neutrons. The neutron exposures left deep marks, like an iron that had burned through a sheet, on the patients’ skin. Hempelmann had a first-rate mind and would soon see for himself how hazardous radioactive materials could be if they were not carefully administered. Nevertheless, he viewed the Berkeley research as the wave of the future.

After four months in Berkeley, Hempelmann went to Memorial Hospital in New York (where Hymer Friedell had just been) and spent another month studying radiation physics.
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Then he returned home to St. Louis. Before the year was out, on Sunday, December 7, 1941, the Japanese attacked Pearl Harbor. Nearly twenty ships and 292 aircraft were destroyed, and 2,403 Americans killed and 1,178 wounded.
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The following day the United States declared war on Japan, Germany, and Italy. Hempelmann, like millions of other young men, would soon be drawn into the war.

Arthur Holly Compton, a handsome man who was just entering his fiftieth year, sat up as straight as he could in his sickbed as the group of scientists climbed the stairs to the third floor of his Chicago town house for the meeting he had called.
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With the visitors came a blast of wintry air and the sense of urgency that had seemed to grip the entire country since President Roosevelt’s declaration of war six weeks earlier. Ernest Lawrence, his handsome face reddened by cold and excitement, sat down on the bed opposite Compton. Luis Alvarez, one of Lawrence’s protégés, sat down next to his mentor. Standing close enough to participate in the discussion but far enough away to reduce the risk of catching cold was Leo Szilard, a brilliant Hungarian physicist known to his friends as “Leo the Lizard.” Two other scientists also had squeezed into the room.

The date was January 24, 1942. The scientists had met at Arthur Compton’s home to decide where a central laboratory should be located for further investigations into the chain reaction. Compton was the head of a National Academy of Sciences committee that had just finished a study concluding that an atomic bomb could be built. It was the most positive and concrete report written to date, providing estimates of the time it would take to build such a weapon, the amount of fissionable material needed, and what it would cost. Although the United States was now officially at war and President Roosevelt recognized that raw materials and manpower would soon be in short supply, he nevertheless was so impressed by Compton’s report that he had given his approval for the
project to proceed to the construction phase on January 19, just five days before the meeting in Compton’s sickroom.

Many scientific advances had been made since December 1938 when radiochemists Otto Hahn and Fritz Strassman split the uranium nucleus in their Berlin laboratory. The German scientists could hardly believe what had happened. They checked and rechecked their findings, and then Hahn contacted a trusted colleague, Lise Meitner, a superb physicist who had been forced to flee Nazi Germany and was living in Sweden. Meitner thought deeply, conducted numerous calculations, and talked the matter over with a nephew, Otto Frisch, also a physicist. She suspected the uranium atom, when it captured the neutron, had become unstable and divided into two parts. Using Albert Einstein’s theory of mass and energy, she calculated the energy released from one atom was equal to 200 million electron volts.
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Meitner was convinced that Hahn and Strassman had indeed split the uranium atom and wrote them a letter of congratulations. Then her nephew set out for Copenhagen to tell Niels Bohr, the great Danish physicist, of the discovery.

Bohr, who was about to board a boat for America, struck his forehead in sudden understanding when he heard the news. As his ship lurched across the Atlantic, Bohr pondered the scientific implications of the discovery. When he reached the United States, Bohr inadvertently leaked news of the Hahn-Strassman experiment and the Meitner-Frisch interpretation to fellow scientists. The information spread like wildfire. The profound ramifications of the discovery were immediately understood by scientists in the United States as well as those working in England, France, Germany, Russia, and Japan.

The physicists suspected that when a uranium atom splits, it might eject two or three more neutrons. Those neutrons could smash into other atoms and break them up. Soon a chain reaction would be ignited in which geometrically increasing amounts of energy would be released. A controlled reaction could be used to generate heat and power. An uncontrolled reaction could lead to an explosion of unimaginable proportions.

Leo Szilard, a balding, portly scientist, had prophesied such a chain reaction even before the German chemists had split the uranium nucleus. When he heard the results of the Hahn-Strassman experiment, his mind leapt ahead to Hitler, whose September 1939 invasion of Poland was still some months away. The Nazi leader would be unstoppable with an atomic weapon in his arsenal.

Szilard, who had an imaginative, restless mind and an uncanny ability
to see into the future, was deeply worried by the news. After discussing the matter with fellow Hungarian scientists Eugene Wigner and Edward Teller, he asked Albert Einstein, then working at Princeton University, if he would use his enormous scientific prestige to help him get a letter of warning to President Roosevelt. Einstein, who had known Szilard for many years, agreed. In a letter dated August 2, 1939 and delivered several months later through an intermediary, Einstein warned Roosevelt that “extremely powerful bombs of a new type” could be constructed.
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The Germans, he added, were already investigating the chain reaction phenomenon.

Responding cautiously at first to Einstein’s appeal, Roosevelt authorized a group of civilian and military representatives to look into the potential military applications of nuclear fission. Scientists working in laboratories at Columbia, Princeton, and Berkeley soon realized that while a bomb was theoretically possible, constructing such a weapon was fraught with enormous technical difficulties. Chief among them was finding a way to enrich uranium to the point it could be used in a fission bomb.

While work progressed on this difficult task, a young chemist in Berkeley named Glenn Seaborg continued the promising research which had been started by his colleague, Edwin McMillan. As soon as news of the German breakthrough reached Berkeley, McMillan had begun bombarding uranium with neutrons produced by the cyclotron. During the process, McMillan and fellow scientist Philip Abelson discovered a new element that lay beyond uranium, then the heaviest known element in the Periodic Table. McMillan called the ninety-third element neptunium, after the planet Neptune. McMillan suspected there was another, even heavier element beyond neptunium, but before he could confirm his hunch, he agreed to go to MIT’s newly established radar laboratory to help with defense work.

After McMillan moved east, Seaborg wrote to him and asked for permission to continue his research.
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McMillan said he would be “pleased” to have Seaborg’s help. Seaborg enlisted the aid of Arthur Wahl, then a graduate student, and Joseph Kennedy, an instructor in UC-Berkeley’s chemistry department, and the assault on the new element began.

Seaborg, a tall scientist with blond hair and hazel eyes who had received his Ph.D. in chemistry at the age of twenty-five from University of California at Berkeley, had been chagrined when he learned that the
Germans were the first to report splitting the uranium atom. But he soon suspected that there was still-uncharted country beyond uranium where new elements were waiting to be identified. Seaborg, who would go on to identify many of those elements, recalled years later, “The new land had not really been discovered.”
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Seaborg’s team began their backbreaking attack on the ninety-fourth element in the fall of 1940. First the uranium had to be bombarded in the cyclotron, where some of it would be transmuted to plutonium. Then the plutonium would have to be isolated through a series of tedious chemical processes. By Tuesday, February 25, 1941, the team had solid evidence that they had isolated the ninety-fourth element.
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It was later confirmed to be plutonium-238, a very radioactive isotope of plutonium with a half-life of about eighty-six years.

But Seaborg was not yet through with his labors. With the help of Emilio Segre, one of Enrico Fermi’s colleagues, he continued to bombard uranium samples in the cyclotron in order to isolate a second isotope, plutonium-239. As the radioactivity increased, the men donned goggles and lead gloves and worked behind lead shields.
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They placed the radioactive mixture in a centrifuge tube, which was inserted into a lead beaker. Then they carried the lead beaker from room to room in a wooden box with long poles, which served as handles. Seaborg and his colleagues finally isolated a minuscule speck of plutonium-239 on March 6. About two weeks later, they completed tests showing that plutonium-239, with a half-life of about 24,000 years, would fission violently.

Although it would be nearly a year before the new substance got its formal name, Seaborg’s team followed McMillan’s lead and called the ninety-fourth element plutonium, after the small planet Pluto that orbits the sun at the outer edges of the solar system. “It really should have been called ‘plutium,” Seaborg said, “but we liked how plutonium rolled off the tongue.”
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Pluto was also the name of the Greek god of the underworld. Deaf to prayers and unmoved by sacrifices, Pluto was the most hated and feared of all the gods. He owned a helmet that rendered him invisible.

Plutonium, also feared and invisible when it was first discovered, offered scientists a second and perhaps more plausible way to build a bomb. Ernest Lawrence immediately recognized its potential. Plutonium-239, he told government officials, could be used to create a “super bomb.” But how would plutonium be produced? Assuming a cyclotron could make a milligram a month, it would take about 500,000 years to
scrape together enough plutonium for a bomb.
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But some other apparatus that could be used to produce plutonium—a nuclear reactor, for example—might do the trick.

At Columbia University, Enrico Fermi was already hard at work on the problem. Fermi, who was awarded the Nobel Prize in 1938 for the discovery of new radioactive substances and his work with slow neutrons, had actually been the first to split the atom in 1934 but didn’t recognize it as such. He was an undisputed genius, a small, wiry man who had learned English from reading Jack London stories. In a drafty laboratory, Fermi and his assistants were engaged in the grimy job of trying to build a crude nuclear reactor by layering chunks of uranium and graphite on top of each other. Fermi called his towering creations “piles” because that’s exactly what they looked like. Fissioning uranium would produce the neutrons; graphite would act as a moderator and slow the neutrons down. Fermi believed the “pile” would be able to sustain a controlled chain reaction once the technicalities were worked out. And then they would have the plutonium they needed to build the bomb.

On the day the scientists crowded into Arthur Compton’s sickroom (actually the bedroom of one of his children), all of these facts were known. With Compton listening, each of the men began pitching his respective university as the best place to build the chain-reacting pile and perform the chemical research on plutonium. Szilard, who was working at Columbia with Fermi, argued that the project should remain in New York. To disassemble the experimental piles, pack up the scientists’ families, and move halfway across the country would mean a loss of valuable time.