Command and Control (20 page)

Shrimp's yield was 15 megatons—
almost three times larger than what its designers had predicted. The fireball was about four miles wide, and
about two hundred billion pounds of coral reef and the seafloor were displaced, much of it rising into a mushroom
cloud that soon stretched for more than sixty miles across the sky. Fifteen minutes after the blast, O'Keefe and the eight other men in his firing crew tentatively stepped out of the bunker. The island was surrounded by a dull, gray haze. Trees were down, palm branches were scattered everywhere, all the birds were gone—twenty miles
from ground zero. O'Keefe noticed that the radioactivity level on his dosimeter was climbing rapidly. A light rain of white ash that looked like snowflakes began to fall. Then pebbles and rocks started dropping from the sky. The men ran back into the bunker, slammed the door shut, detected high levels of radioactivity within the bunker, and after a few moments of confusion, turned off the air-conditioning unit. Inside, the radiation levels quickly fell, but outside they continued to rise. The men were trapped.

The dangers of radioactive fallout had been recognized since the days of the Manhattan Project but never fully appreciated. A nuclear explosion produces an initial burst of gamma rays—the source of radiation poisoning at Hiroshima and Nagasaki. The blast also creates residual radiation, as fission products and high-energy neutrons interact with everything engulfed by the fireball. The radioactive material formed by the explosion may emit beta particles, gamma rays, or both. The beta particles are relatively weak, unable to penetrate clothing. The gamma rays can be deadly. They can pass through the walls of a house and kill the people inside it.

Some elements become lethal after a nuclear explosion, while others remain harmless. For example, when oxygen is bombarded by high-energy neutrons, it turns into a nitrogen isotope with a half-life of just seven seconds—meaning that within seven seconds, half of its radioactivity has been released. That's why a nuclear weapon exploded high above the ground—an airburst, like the detonations over Hiroshima and Nagasaki—doesn't produce much radioactive fallout. But when manganese is bombarded by high-energy neutrons, it becomes manganese-56, an isotope that emits gamma rays and has a half-life of two and a half hours. Manganese is commonly found in soil, and that's one of the reasons that the groundburst of a nuclear weapon can create a large amount of deadly fallout. Rocks, dirt, even seawater are transformed into radioactive elements within the fireball, pulled upward, carried by the wind, and eventually fall out of the sky.

The “early fallout” of a nuclear blast is usually the most dangerous. The larger particles of radioactive material drop from the mushroom cloud within the first twenty-four hours, landing wherever wind or rain carries them. On the ground, radiation levels steadily increase as the fallout accumulates. Unlike the initial burst of gamma rays from a nuclear explosion,
the residual radiation can remain hazardous for days, months, or even years.
A dose of about 700 roentgens is almost always fatal to human beings—and that dose need not be received all at once. Radiation poisoning, like a sunburn, can occur gradually. Gamma rays are invisible, and radioactive dust looks like any other dust. By the time a person feels the effects of the radiation damage, nothing can be done to reverse it.

“
Delayed fallout” poses a different kind of risk. Minute particles of radioactive material may be pulled into the upper atmosphere and travel thousands of miles from the nuclear blast. Most of the gamma rays are emitted long before this fallout lands. But a number of radioactive isotopes can emit beta particles for long periods of time. Strontium-90 is a soft metal, much like lead, with a radioactive half-life of 29.1 years. It is usually present in the fallout released by thermonuclear explosions. When strontium-90 enters the soil, it's absorbed by plants grown in that soil—and by the animals that eat those plants. Once inside the human body, strontium-90 mimics calcium, accumulates in bone, and continues to emit radiation, often causing leukemia or bone cancer. Strontium-90 poses the greatest risk to children and adolescents, whose bones are still growing. Along with cesium-137, a radioactive isotope with a half-life of 30 years, it may contaminate agricultural land for generations.

In 1952, Mike's thermonuclear explosion had deposited high levels of fallout in the ocean near the test site. The following year, New York milk tainted with strontium-90 was linked to the detonation of fission devices at the Nevada Test Site. But the unanticipated size of Shrimp's yield, the volume of coral reef and seafloor displaced, and the stronger-than-expected winds combined to produce
an amount of fallout that surprised everyone involved with the Bravo test. Thousands of scientists and military personnel, watching the detonation from ships thirty miles away, were forced to head belowdecks and remain there for hours amid stifling heat. O'Keefe and his men had to be rescued by helicopter. They taped bedsheets over every inch of their bodies before fleeing the bunker, trying to avoid any contact with the fallout.

Seaplanes evacuated an Air Force weather station 153 miles from ground zero, and two days after the blast, the Navy removed scores of villagers
from the island of Rongelap in the Marshall Islands.
The villagers had seen the brilliant explosion 115 miles in the distance but had no idea the white dust that later fell from the sky might be harmful. It settled on their skin and in their hair. They walked barefoot in it for hours. About eighty of them got radiation sickness. Many also developed burns, lesions, and discolored pigment from beta particles emitted by the fallout on their skin. And Rongelap was blanketed with so much of the white dust that the island's residents weren't allowed to return there for three years.

The dangers of fallout were inadvertently made public when
a Japanese fishing boat, the
Lucky Dragon,
arrived at its home port of Yaizu two weeks after the Bravo test. The twenty-three crew members were suffering from radiation poisoning. Their boat was radioactive—and so was the tuna they'd caught. The
Lucky Dragon
had been about eighty miles from the detonation, well outside the military's exclusion zone. One of the crew died, and the rest were hospitalized for eight months. The incident revived memories of Hiroshima and Nagasaki, sparking protests throughout Japan. When Japanese doctors asked for information about the fallout, the American government refused to provide it, worried that details of the blast might reveal the use of lithium deuteride as the weapon's fuel. Amid worldwide outrage about the radiation poisonings, the Soviet Union scored a propaganda victory. At the United Nations, the Soviets called for an immediate end to nuclear testing and the abolition of all nuclear weapons. Although sympathetic to those demands, President Eisenhower could hardly agree to them, because the entire national security policy of the United States now depended on its nuclear weapons.

•   •   •

T
HE
FATE
OF
THE
L
UCKY
D
RAGON
was soon forgotten. But the Bravo test led to an alarming realization at the weapons laboratories, the Pentagon, and the White House: fallout from a hydrogen bomb was likely to kill far more people than the initial blast. At the Atomic Energy Commission,
the fallout pattern from the Bravo test was superimposed on a map of the northeastern United States, with Washington, D.C., as ground zero. According to the map,
if a similar 15-megaton groundburst hit the nation's
capital, everyone in Washington, Baltimore, and Philadelphia could receive a fatal dose of radioactivity. Residents of New York City might be exposed to 500 roentgens, enough to kill more than half of them. People as far north as Boston or even the Canadian border might suffer from radiation poisoning.

The British prime minister, Winston Churchill, was disturbed by the results of the Bravo test. Churchill had been an early proponent of defending Western Europe with nuclear weapons, not conventional forces. In 1952, Great Britain detonated a fission device, and
its first atomic bomb, the “Blue Danube,” had recently been transferred to the Royal Air Force. The Blue Danube, with
a yield of about 16 kilotons, now appeared minuscule and obsolete. “
With all its horrors, the atomic bomb did not seem unmanageable as an instrument of war,” Churchill told the House of Commons a month after the Bravo test. “But the hydrogen bomb carries us into dimensions which . . . have been confined to the realms of fancy and imagination.” A small, densely populated nation would be especially vulnerable to such a weapon. Churchill asked William Strath, an official at the Central War Plans Secretariat, to lead a top secret study of what a thermonuclear attack would do to the United Kingdom.

Strath submitted his report in the spring of 1955, and its findings were grimly apocalyptic. According to the latest intelligence, a Soviet assault on the United Kingdom would have three main objectives: destroy the airfields hosting U.S. or British bombers, destroy the British government, and “
render the UK useless as a base for any form of military operations.” That would be relatively easy to accomplish. “
The heat flash from one hydrogen bomb,” the Strath report noted, “would start in a built-up area anything up to 100,000 fires, with a circumference of between 60 to 100 miles.”
If the Soviets detonated ten hydrogen bombs along the west coast of the United Kingdom, the normally prevailing winds would blanket most of the country with fallout.
Almost one third of the British population would be killed or wounded immediately. Most of the nation's farmland would be rendered unusable for two months, some of
the most productive land might “be lost for a long time,” and supplies of drinking water would be contaminated. In a section entitled “
Machinery of Control,” the report warned that society
would collapse in much of the United Kingdom. Local military commanders would be granted “
drastic emergency powers,” and civil order might have to be restored through the use of “rough and ready methods.” Strath urged the government to release accurate information about the hydrogen bomb so that families could build fallout shelters, store canned foods, and prepare for the worst.

The Strath report was kept secret, its plea for greater openness ignored. Instead, Prime Minister
Churchill ordered the BBC not to broadcast news about the hydrogen bomb that might discourage the public. Telling the truth about nuclear weapons, the British government feared, would weaken popular support for a defense policy that required them. Churchill had already chosen a different sort of response to the threat of thermonuclear war. “
Influence depended on possession of force,” he told advisers, not long after the Bravo test. Great Britain would develop its own hydrogen bombs. Once again, the appeal of the H-bomb lay in its symbolism. “
We must do it,” Churchill explained. “It's the price we pay to sit at the top table.”

The Eisenhower administration also struggled with how to handle public fears of the hydrogen bomb. The head of the Atomic Energy Commission, Lewis Strauss, waited almost a year to acknowledge that the Bravo test had spread lethal fallout across thousands of square miles. While Strauss tried to limit publicity about the dangers of fallout, the Federal Civil Defense Administration (FCDA) conveyed a different message. Val Peterson, the head of the FCDA, advised every American family to
build an underground shelter “right now.” Once the Soviets deployed their hydrogen bombs, Peterson added, “
we had all better dig and pray.”

The FCDA had argued for years that people could survive a nuclear attack by seeking some form of shelter. An animated character, Bert the Turtle, urged America's schoolchildren to “duck and cover”—to hide under classroom tables or desks as soon as they saw the flash of an atomic bomb. And a widely distributed civil defense pamphlet, “Survival Under Atomic Attack,” provided useful and encouraging household tips:

YOUR CHANCES OF SURVIVING AN ATOMIC ATTACK ARE BETTER THAN YOU MAY HAVE THOUGHT. . . .
EVEN A LITTLE
MATERIAL GIVES PROTECTION FROM FLASH BURNS, SO BE SURE TO DRESS PROPERLY. . . .
WE KNOW MORE ABOUT RADIOACTIVITY THAN WE DO ABOUT COLDS. . . .
KEEP A FLASHLIGHT HANDY. . . .
AVOID GETTING WET AFTER UNDERWATER BURSTS. . . .
BE CAREFUL NOT TO TRACK RADIOACTIVE MATERIALS INTO THE HOUSE. . . .

The destructive power of the hydrogen bomb forced civil defense planners to alter their recommendations. Suburban families were advised to remain in underground shelters, windowless basements, or backyard trenches for four or five days after a thermonuclear blast. Urban families were told to leave their homes when an attack seemed likely. Eisenhower's plans for an interstate highway system were justified by the need to evacuate American cities during wartime.
Val Peterson called for concrete pipelines to be laid alongside the new roads, so that refugees could sleep inside them and avoid fallout. “
Duck and cover,” one journalist noted, was being replaced by a new civil defense catchphrase: “Run for the hills.”

Hoping to boost morale and demonstrate that a nuclear war would not mean the end of the world, the FCDA staged Operation Alert 1955 during June of that year. It was the largest civil defense drill in the nation's history. During a mock attack,
sixty-one cities were struck by nuclear weapons, ranging in yield from 20 kilotons to 5 megatons. As air-raid sirens warned that Soviet bombers were approaching, fifteen thousand federal employees were evacuated from Washington, D.C. The president and members of his Cabinet were driven to secret locations and remained there for three days. Throughout the United States, families climbed into shelters or rehearsed their escape routes. In New York City, everyone was cleared from the streets and kept indoors for ten minutes, bracing for the arrival of a Soviet hydrogen bomb—whose ground zero, for some reason, would be
the corner of North 7th Street and Kent Avenue in Williamsburg, Brooklyn.