Pandora's Keepers (12 page)

Compton was not above some personal lobbying of his own. After submitting the report to Bush, he arranged a game of tennis
with his personal friend, Vice President Wallace. As they chatted on the court, Compton told Wallace that Bush would soon
be showing the president a report. “Please give it your most careful attention,” he said. “It is possible that how we act
on this matter may make all the difference between winning and losing the war.”
²⁹

Bush carried Compton’s report to the White House on November twenty-seventh. The weather that day was cold and the news was
bleak. Hitler’s armies, which had invaded Russia in June, had reached the outskirts of Moscow and a crisis was brewing between
America and Japan in the Far East. Bush proposed to Roosevelt an all-out effort to build a bomb. He told FDR that although
Britain was ahead of the United States in bomb research, it lacked the resources to build one and looked to America to do
so, if it was possible. The United States was the only country with uncommitted and protected resources sufficient to make
an atomic bomb during the war.

Roosevelt followed intently. He had listened to Sachs and his account of the refugee physicists’ fears, and had politely thanked
Einstein. But what he had now was not a vague idea but a clear proposal for action that came with the combined authority of
British science and an American scientist whom he trusted. This combination had the commanding prestige that was necessary
to give credibility to something as implausible as a one-kilogram device with an explosive force of some two thousand tons.
And so, on December 6, 1941—just one day before Japan attacked Pearl Harbor and plunged the United States into the war—FDR
put the vast resources of the government behind an all-out effort to build an atomic bomb.
³⁰
The authority for deciding how the bomb would be used went to the Top Policy Group he had named earlier. The assumption that
the bomb would be built quickly for use during the war was implicit in the decision to develop it.

Now the entire governmental machine began to get to work on the effort, code-named the Manhattan Project, after the headquarters
of the Army Corps of Engineers’ district tasked to manage it. Bush appointed Conant to oversee the scientific project from
Washington and gave Compton responsibility for academic research throughout the country. Bush also made clear the government’s
intent to maintain authority over the project and to transfer it to the army’s control when large-scale production of fissionable
materials became necessary. His reasons were simple: Bush knew the money was running out from sources at his disposal and
much more was going to be needed. By bringing in the military, he could conceal the project’s costs within the Army Corps
of Engineers’ enormous appropriation under line items dubbed “Procurement of New Materials” and “Expediting Production.” Roosevelt
did not want to have to justify the Manhattan Project on the Hill. This might slow down the project and jeopardize its secrecy.
³¹

Many of the physicists who would soon be brought into the Manhattan Project were refugees, recent immigrants to the United
States. This was partly because they included some of the world’s best physicists, but there was another reason as well: many
native-born American physicists had been swept up earlier in military research on radar and the proximity fuse, which appeared
to have a more immediate military application to Allied success in the war. As a result, refugees were the main remaining
source of available scientific brainpower to work on the project. The very restrictions and limitations imposed upon refugee
scientists—which had delayed the government’s embrace of the project—facilitated their leading roles in the bomb’s development
once the government decided to support it.
³²
This irony would have a significant, if unstated, impact down the road, when disputes arose about the long-term political
consequences of what the scientists and the government were doing.

In the end, the refugee physicists and their native-born colleagues did not protest their loss of control over the project
in December 1941. Most of them, in fact, welcomed it because they thought it would insulate them from political pressure and
criticism. Their acceptance of this condition was the tacit price of their admission into the project. It was also a measure
of their loyalty by those at the top. “I think [Ernest Lawrence] now understands this,” Bush said, “and I am sure Arthur Compton
does, and I think our difficulties in this regard are over.”
³³
The government was giving physicists, whom Bush and others in top councils considered “somewhat naive and lacking in discretion,”
³⁴
the responsibility for making an atomic bomb, not for helping to decide how it would be used.

Oak Ridge was a remote rural area surrounding the Clinch River eighteen miles from Knoxville, Tennessee. It was beautiful
country, rolling hills dotted with dogwood, oak, and pine trees, and situated between the Great Smoky Mountains to the east
and the Cumberland Mountains to the west. It answered all the requirements for a sprawling plant to separate U-235 isotopes:
an isolated area in the midst of the vast power grid of the Tennessee Valley Authority, an abundant water supply, relatively
few people to relocate, good access by road and train, and a mild climate that permitted outdoor work the year round. Here
on a 59,000-acre site, 32,000 construction workers built and 47,000 operating personnel maintained a gigantic forty-two-acre
separation plant flanked by facilities covering some fifty additional acres and containing more than six thousand miles of
pipe that was the largest factory complex on earth when it was finished.

U-235 was separated at Oak Ridge by three different methods—no one knew which would prove most effective. The first method
was electromagnetic separation, using giant cyclotrons designed by Ernest Lawrence. Uranium atoms were stripped of electrons
in a vacuum. Then they were electrically charged and thus made more susceptible to outside magnetism. The heavier U-238 was
more sluggish, so the lighter U-235 could gradually and painstakingly be separated out. The enormous separation chambers contained
vacuum pumps, more powerful than any ever built, that pushed through millions of gallons of oil a day; the magnet coil windings
required 27,750,000 pounds of silver (the metal, worth $400 million at 1940s prices, was borrowed from the Treasury Department).

The second method was gaseous diffusion, developed by Columbia University physicists Harold Urey and John Dunning. When ordinary
uranium was mixed with fluorine, the resulting compound—uranium hexafluoride—was a gas. When the uranium hexafluoride gas
was forced through the microscopic membrane holes of a filter (or “barrier,” as it was also called), the lighter U-235 passed
through faster and the gas on the far side was marginally enriched with the desired isotope. When the process was repeated,
the proportion of U-235 increased a little more. Bomb-grade uranium—containing 90 percent U-235—required thousands of passes
through the filters.

The third method of U-235 separation was thermal diffusion, pioneered by a former student of Lawrence’s working at the Naval
Research Laboratory named Philip Abelson. The apparatus was simple. Long, vertical, concentric pipes were enclosed in cylinders
that resembled a gigantic church organ. Each cylinder was composed of a thin nickel pipe within a copper pipe. These two pipes,
in turn, were encased in a third one made of galvanized iron. When uranium hexafluoride gas was passed between the hot nickel
pipe and the cool copper pipe, the lighter U-235 concentrated near the hot nickel wall and moved upward, while the heavier
U-238 moved downward along the cool copper wall. The enriched uranium was then skimmed off at the top. Thermal diffusion could
increase the percentage of U-235 in natural uranium by only a small amount, but the enrichment was sufficient to supplement
the gaseous diffusion method as another source of material for the electromagnetic racetracks, whose efficiency soared tremendously
when fed with even slightly enriched uranium.

The names of the processing plants at Oak Ridge sounded like the combination to a safe: X-10, Y-12, S-50, K-25. All plants
except X-10, a plutonium research lab, performed the same function: extracting precious U-235 from U-238. At S-50, thermal
diffusion was employed; at Y-12, electromagnetic separation was applied; at K-25, the process was gaseous diffusion. K-25
was the largest building ever constructed up to that time. It was a sight to behold. Spread over 2 million square feet, the
U-shaped structure was half a mile long and four hundred feet wide on each side. It was so vast that foremen rode bikes from
one part of the building to another. Twelve thousand people, working in three shifts, kept K-25 running day and night, seven
days a week. When it was operating, a continuous hum—a high-pitched sound resembling the buzzing of a bee swarm—came from
the plant, mixing weirdly with the noises from the nearby woods. The electricity for these mammoth facilities came from the
nearby TVA and an on-site powerhouse that was the largest power installation ever built. By war’s end, Oak Ridge would be
consuming the equivalent of the total power output on the American side of Niagara Falls—or one-seventh of all electricity
generated in the United States.

Lawrence toured the sprawling complex as it was being built, and thrilled at the spectacle. “What you’re doing here is very
important,” he told construction workers assembled to hear him give a pep talk. Oak Ridge was a realization of his vision
of big physics, and it made him feel proud—like King Henry V addressing his troops before the Battle of Agincourt. “A hundred
years from now, people may not remember that there was a war on now,” he told them, emotion rising in his voice, “but they
will remember what you were doing.”
³⁵
Privately, Lawrence was awed by what lay ahead. “When you see the magnitude of that operation there,” he wrote after returning
to Berkeley, “it sobers you up and makes you realize that whether we want to or not, we’ve got to make things go. We must
do it!”
³⁶

The magnets of the cyclotrons that Lawrence had built at Oak Ridge were 250 feet long, and each contained thousands of tons
of steel. They were a hundred times larger than the magnet of the 184-inch Berkeley cyclotron—previously the largest in the
world. Their magnetic field was so strong that a wrench would be wrested from a workman’s hand, or if he held onto it, he
would be pulled against the magnet. But the U-235 separated by these giant cyclotrons offered itself up in only minuscule
quantities. Yields were so low from the tons of uranium ore being processed that workers carefully plucked mere specks from
their white overalls with tweezers. There were times when they got down on their hands and knees to look for tiny bits of
the precious fissionable material.

In south-central Washington State, the small town of Hanford sat in the midst of a vast area of sagebrush and sand, twenty
miles north of Richland, bounded on three sides by a huge bend in the Columbia River. This unusual combination—large amounts
of water flowing through sparsely peopled desert—made the site suitable for another prong of the Manhattan Project. The Columbia
River would provide the enormous amount of water necessary to cool three gigantic piles to be built there for the production
of plutonium, an alternative (and more easily obtained) source of fissionable material for the bomb. The isolated location—the
population density was just 2.2 persons per square mile—would mitigate the effects of any accidental radioactive release and
be easy to guard. In time, the Hanford facility would grow to more than 428,000 acres—500 square miles.
³⁷

To recruit a massive labor force of construction workers for the Hanford site at a time when every war industry in America
was begging for manpower was an extraordinary task. The White House cabled regional employment offices, giving preference
by direction of the president himself to the Hanford Engineering Works, as it was called, and authorizing them, if necessary,
to draft workers from the aircraft industry. In some towns of the Northwest, clergymen were asked to promote Hanford from
the pulpit. Veterans of many big public works projects—men who had helped construct huge dams and power plants—had never seen
so many people working in the same place at the same time. Living in barracks and trailer camps, they created a massive, sprawling
physical plant. The statistics were stunning: 540 structures, more than 600 miles of blacktop, 158 miles of track. Eventually,
132,000 workers (working 126 million man-hours) signed on—nearly as many as had labored to build the Panama Canal. Hanford
soon became the fourth-largest city in the state of Washington. The ultimate price of Hanford would reach $358 million, or
nearly $5 billion in 2004 dollars.
³⁸

Hanford’s three all-important piles—each one processed two hundred tons of uranium for two hundred days—produced the plutonium,
but equally important were the chemical-separation plants that treated the uranium slugs irradiated in the piles. These slugs
were so radioactive when they came out that they glowed.
³⁹
Three chemical-separation plants were built in isolated and heavily guarded desert areas south of nearby Gable Mountain.
For safety reasons—the plutonium in the irradiated slugs was also highly radioactive—the plants were placed ten miles from
the nearest pile and well apart from one another. No one wanted to discover an atomic blast by accident.

The separation plants were sinister-looking, windowless structures with walls eight feet thick—in effect, huge concrete coffins
eight hundred feet long and eighty feet wide. Each contained an underground row of forty cells where the irradiated slugs
were processed. The operating gallery that ran above the cell rows was a silent, deadly radioactive tunnel with glaring electric
lamps, where no human being could survive. Because of plutonium’s deadly toxicity, metallurgists had to be specially trained
to handle it. They wore rubber gloves, worked behind protective shielding, and manipulated the plutonium with long tongs.
Not only was the air filtered and ventilated, but a microscopist was hired to analyze its dust. In these gargantuan coffin-
like structures, workers operating remote-control machinery around the clock tortuously squeezed out plutonium in a concentration
of about 250 parts per million, a half-pound radioactive pellet from every ton of irradiated uranium.