Command and Control (45 page)

“
The possibility of an accidental nuclear explosion taking place is essentially negligible,” the director of nuclear safety at Kirtland Air Force Base told CBS News. The Atomic Energy Commission said much the same thing to the
New York Times
, claiming the odds were “
so remote that they can be ruled out completely.” But a number of scientists and engineers at Sandia didn't share that degree of optimism. Bob Peurifoy felt uneasy that a simple, low-voltage signal, lasting a few seconds, was still being used to arm hydrogen bombs. That kind of signal dated back to the days of Thomas Edison—and it could come from a lot of places as a B-52 fell apart. It could come from a short circuit during an otherwise uneventful flight. Peurifoy thought that a more complicated signal—a unique series of electrical pulses—could prevent a bomb from being armed accidentally. Transmitted between the ready/safe switch in the cockpit and the nuclear weapon in the bomb bay, it would operate much like a secret code, alternating long and short pulses in a pattern that fate, bad luck, or even Mother Nature couldn't randomly generate.

Another engineer, Thomas Brumleve, criticized the air of overconfidence at Sandia, the overemphasis on reliability, the faith that an accidental detonation could never happen. “
But suppose some important aspect of nuclear safety has been overlooked,” Brumleve wrote in a 1967 report. “
The nation, and indeed the world, will want to know
who was responsible
,
how it could have happened
, and
why it wasn't prevented
.”

On January 21, 1968,
a B-52 was serving as the Thule monitor. For hours it flew a “bowtie” pattern at thirty-five thousand feet, heading back and forth above the ballistic missile early warning complex in western Greenland. One of the copilots, Major Alfred D'Amario, Jr., had stuffed
three cloth-covered, foam-rubber cushions beneath the instructor navigator's seat, and someone later put a fourth one under it, keeping the cushions wedged in place with a small metal box. The cushions might ease the discomfort of a long, tedious mission. About five hours into the flight, the crew noticed that the heat wasn't working properly. The cockpit felt too cold, and so D'Amario turned on a system that pulled air from the engine
manifold into the cabin. The air was hot,
about 428 degrees Fahrenheit. It ignited the cushions, which were blocking a vent under the seat.

The radar navigator, Major Frank F. Hopkins, thought he smelled something burning. It smelled like burning rubber. The crew looked for the source of the smoke, found it, sprayed the cushions with fire extinguishers, but couldn't put out the fire. The pilot, Captain John Haug, asked the control tower at Thule for permission to conduct an emergency landing. As Haug started the descent, Hopkins opened the sextant port, a small hole in the fuselage, to let out smoke. The navigator, Captain Curtis R. Criss, tried to smother the burning cushions with a duffle bag. But the flames spread, and the smoke in the cockpit became so thick that Haug could barely see the instrument panel. He told Thule that the fire was out of control. Moments later, the plane lost all its power.

The crew would have to bail out into some harsh weather. The
temperature that day in western Greenland was -23 degrees Fahrenheit; the
windchill made it feel like -44. Haug wanted to get as close as possible to Thule and increase the odds of his crew's survival—without crashing the B-52 into the base. Although their mission was simply to keep an eye on Thule and make sure that it still existed, the plane carried four Mark 28 bombs.

Haug stayed with the plane until everyone was out and then ejected, just four miles short of the runway. The B-52 passed right over Thule, made a 180-degree turn, flew another few miles, and slammed into the ice of Bylot Sound. The explosion caught most of the men on the base by surprise, shaking the buildings and lighting up the sky. It was about four thirty in the afternoon but completely dark outside. The sun hadn't been seen in Thule for almost two months, since late November. Except for a brief period of dim light in the afternoon, the snow-covered landscape around the base seemed dark as night.
SAC headquarters was notified, for the first time, about the fire on the plane, the crash, and the explosion. The command post at Thule had no idea if there were any survivors. And then Major D'Amario walked into one of the aircraft hangars and asked to use a phone. His parachute had deposited him near a runway. D'Amario told the base commander that at least six of the seven crew members had bailed out. Security police officers split into teams and got into trackmasters to find
them, driving the large vehicles out of the base. Helicopters soon joined the search. In the Arctic weather, every minute counted:
uncovered skin could become frostbitten within two.

Haug parachuted onto the base as well, and made his way to a different hangar. He and D'Amario had suffered only scrapes and bruises. About an hour after the crash, the gunner, Sergeant Calvin Snapp, was found in good shape near the dump. A couple of parachutes and ejection seats were spotted from a helicopter, three miles from Thule, along with footprints in the snow. Security police followed them to the base of a nearby mountain, where Major Hopkins and a copilot, Captain Richard Marx, had gone looking for help. Marx had bruises and abrasions; Hopkins, a broken arm. The body of Captain Leonard Svitenko, another copilot, was discovered at around midnight. He'd died leaving the plane. And almost a full day after the crash, the last remaining crew member, the navigator, Captain Criss, was found wrapped in his parachute, six miles from the base, suffering from frostbite, hypothermia, a dislocated shoulder. Criss was forty-three years old and eventually lost both of his feet.
But he later worked as a postmaster in Maine, kept playing golf, and lived for another forty years.

The B-52 had struck the ice at a speed of almost six hundred miles per hour, about seven miles west of Thule. The high explosives of the four hydrogen bombs fully detonated upon impact, and roughly 225,000 pounds of jet fuel created a large fireball. For five or six hours, the fire burned, until being extinguished by the ice. When the first Explosive Ordnance Disposal team arrived at the site two days later, using flashlights and traveling from Thule on a dogsled, they found a patch of blackened ice about 720 yards long and 160 yards wide. Pieces of the bombs and the plane were scattered across an area of three square miles. The pieces were small—and highly radioactive. Tiny particles of plutonium had bonded with metal and plastic debris, mixed with jet fuel, water, and ice. Plutonium had risen in the smoke from the fire and traveled through the air for miles.

The one-point safety tests of the Mark 28's core, performed secretly at Los Alamos during the Eisenhower administration, had been money well spent. If the Mark 28 hadn't been made inherently one-point safe, the bombs that hit the ice could have produced a nuclear yield. And the partial
detonation of a nuclear weapon, or two, or three—without any warning, at the air base considered essential for the defense of the United States—could have been misinterpreted at SAC headquarters. Nobody expected the Thule monitor to destroy Thule. Instead, the Air Force had to confront a less dangerous yet challenging problem: how to decontaminate about three square miles of ice, about seven hundred miles north of the Arctic Circle, during the middle of winter, in the dark.

Generators, floodlights, a helicopter pad, sleds, tracked vehicles, and half a dozen prefabricated buildings were brought to the crash site. New roads from the base were cut through the snow. A “Hot Line” was drawn around the contaminated area, with restrictions on who could enter it and decontamination control points for everyone who left it. Once again hundreds of young airmen walked shoulder to shoulder, looking for bomb parts and pieces of a B-52. Most of the debris was small, ranging from the size of a dime to that of a cigarette pack. Some of it had fallen through a gash in the ice, cut by the crash, that later refroze. The ice was about two feet thick; the water below it six hundred feet deep. Pieces of the bomb and the plane were carried away by the current or settled on the bottom of Bylot Sound.

Arctic storms with high winds complicated the recovery and cleanup efforts, spreading plutonium dust and hiding it beneath the snow. But the levels of contamination were more accurately measured at Thule than at Palomares. A new device, the Field Instrument for the Detection of Low-Energy Radiation (FIDLER), looked for the X-rays and gamma rays emitted by plutonium, instead of the alpha particles. Those rays traveled a longer distance and passed through snow. Over the next eight months, the top two inches of the blackened ice within the Hot Line were removed, trucked to the base, condensed, packed in containers, shipped to Charleston, South Carolina, and then transported by rail to the AEC facility in Aiken.
The radioactive waste from Thule filled 147 freight cars.

During the summer of 1968, after Bylot Sound thawed, a Navy submersible searched for part of a Mark 28 bomb. The plutonium cores of the primaries in all four weapons had been blown to bits, and most of the uranium from their secondaries had been recovered. But a crucial piece of one
bomb was still missing, most likely the enriched uranium spark plug necessary for a thermonuclear blast. It was never found—and the search later inspired erroneous
claims that an entire hydrogen bomb had been lost beneath the ice.

The Air Force did a much better job of handling the press coverage at Thule than at Palomares. It helped that the B-52 had crashed near one of the most remote military installations in the world, far from any cities, towns, or tourists. An accident that contaminated three square miles of a large metropolitan area would have gained more attention. The Air Force admitted, from the outset, that nuclear weapons had been involved in the crash. Dozens of journalists were flown to Thule within days of the accident and supplied with a good deal of information. Few had the desire to remain in the Arctic for long. And a couple of other news stories—the seizure of the USS
Pueblo
by North Korea and the Tet offensive in Vietnam—quickly pushed Thule off the front page.

The Air Force account of the accident, however, was deliberately misleading. Denmark had imposed a strict ban on nuclear weapons, and its NATO allies were forbidden to bring them into Danish territory or airspace. For more than a decade, the Strategic Air Command had routinely violated that prohibition at Thule.
The B-52 that crashed onto the ice, the Pentagon told reporters, had been on a “training flight” and had radioed that it was preparing to make an emergency landing.
A handful of people within the Danish government and its military were no doubt aware that B-52s had been flying nuclear weapons over Danish territory every day for almost seven years. But they may not have known that atomic bombs were
stored in secret underground bunkers at Thule as early as 1955. Hydrogen bombs were deployed there the following year. Before the introduction of SAC's airborne alert, Thule was a convenient spot for American bombers to land, refuel, and pick up their weapons en route to the Soviet Union. The early hydrogen bombs were so heavy that prepositioning them in Greenland would allow SAC's planes to make the long round-trip flight to Russia over the North Pole. Dozens of
antiaircraft missiles with atomic warheads were later placed at Thule to defend the base from a Soviet attack. But none of these facts were shared with the Danish people.

The airborne alert program was terminated the day after the Thule accident. The risks no longer seemed justifiable, and many B-52s were now being used to bomb Vietnam. SAC's ground alert was unaffected by the new policy. Hundreds of planes, loaded with hydrogen bombs, still sat beside runways all over the United States, ready to take off within minutes. And a B-52 secretly continued to fly back and forth above Thule, day and night, without nuclear weapons, just to make sure it was still there.

•   •   •

T
WENTY
-
THREE
YEARS
AFTER
Sandia became a separate laboratory, it created a nuclear weapon safety department. An assistant to the secretary of defense for atomic energy, Carl
Walske, was concerned about the risks of nuclear accidents. He had traveled to Denmark, dealt with the aftermath of the Thule accident, and come to believe that the safety standards of the weapons labs were based on a questionable use of statistics. Before a nuclear weapon could enter the stockpile, the odds of its accidental detonation had to be specified, along with its other “military characteristics.” Those odds were usually said to be one in a million during storage, transportation, and handling. But the dimensions of that probability were rarely defined. Was the risk one in a million for a single weapon—or for an entire weapon system? Was it one in a million per year—or throughout the operational life of a weapon? How the risk was defined made a big difference, at a time when the United States had about thirty thousand nuclear weapons. The permissible risk of an American nuclear weapon detonating inadvertently could
range from one in a million to one in twenty thousand, depending on when the statistical parameters were set.

Walske issued new safety standards in March 1968. They said that the “
probability of a premature nuclear detonation” should be no greater than one in a billion, amid “
normal storage and operational environments,” during the lifetime of a single weapon. And the probability of a detonation amid “abnormal environments” should be no greater than one in a million. An abnormal environment could be anything from the heat of a burning airplane to the water pressure inside a sinking submarine. Walske's safety standards applied to every nuclear weapon in the American stockpile. They
demanded a high level of certainty that an accidental detonation could never occur. But they offered no guidelines on how these strict criteria could be met. And in the memo announcing the new policy, Walske expressed confidence that “
the adoption of the attached standards will not result in any increase in weapon development times or costs.”