Postscript : A Diplomatic Fallout : Twenty-seven years later, Denmark reopens the file on Danes who helped clean up the crash of an American B-52 carrying nuclear bombs. Plutonium may also be missing.

When President Clinton announced plans in January to declassify hundreds of millions of secret Cold War-era documents held by federal agencies, Denmark and its sensitivities were probably far from his mind.

But a trove of newly released U.S. documents, spirited to Copenhagen over the Internet, has reawakened a 27-year-old diplomatic quarrel involving the 1968 crash near Thule, Greenland, of a nuclear bomb-laden B-52, the dispersal of plutonium and other toxic materials over what is in fact Danish soil and the health of more than 1,000 Danes.

“The government now believes that earlier investigations didn’t look into all the possible damage,” said Lars Tybjerg, the Danish prime minister’s chief adviser on economic and domestic policy.

Having reviewed the newly public documents, the Danish government now wants to know whether as much as two kilograms of plutonium are unaccounted for, and what the United States can do to find traces of the highly toxic element and clean them up.

The release of the files has also prompted Denmark to design a new study of people who were working near the crash site in 1968, some of whom have been saying for years that they suffer from premature aging, extreme fatigue, undiagnosed skin diseases, immune system deficiencies and other problems.

The Greenlanders, Danish citizens, have been examined several times already, and most of the previous tests have failed to establish a link between their health complaints and their possible exposure to nuclear and chemical contaminants in the wake of the bomber crash. One test suggested they might have a higher rate of cancer, but it was not conclusive.

In any case, Danish families affected by the crash remain deeply suspicious. They argue that their country is small and has no nuclear power plants or weapons installations and, consequently, lacks the experience to properly evaluate the health consequences of a nuclear accident.

“If you go to your family doctor and say, ‘I think I’m sick because I’ve been exposed to radiation,’ they don’t take you seriously,” said Sally Schnell, the widow of a onetime transportation personnel manager near the crash site.

Schnell said she has become “a kind of mother for the Thule workers” since her husband died in 1991, having made it her life’s work to bring the men who claim to have been affected together informally and pool information about their symptoms.

In Copenhagen, the government wants to allay these suspicions, taking the new information and carrying out “a thorough investigation, one which can be carried out without any possible complaint that the researchers were biased,” said Tybjerg, the prime minister’s adviser. “If this new investigation demonstrates that these poor people have been damaged, or have a higher-than-normal mortality, then of course they would have to be compensated. And 75% of the bill would be shipped across the ocean” to the United States.

It was January, 1968, when a B-52 bomber with four 1.1-megaton hydrogen bombs on board crashed on the sea ice just off the coast of Greenland--a huge arctic island and a county of Denmark. The bomber was part of “Operation Chrome Dome,” the United States’ Cold War program to keep a fleet of nuclear bombers in the air 24 hours a day, close enough to Soviet airspace to make clear to the Soviets that the United States would strike back if Moscow initiated a nuclear attack.

The Chrome Dome airplanes were cruising three routes in those years, one over the Mediterranean, one over Alaska and one from the northeastern United States up to Greenland. It was the seven-member crew of a B-52 on this last route that found it too cold in the cockpit one January day, turned up the heat full blast and accidentally started an electrical fire in the heater’s wiring.

With smoke filling the cockpit and electrical power shutting down, the crew tried to make an emergency landing at Thule, the United States’ air base in coastal Greenland. But the pilots lost control of the plane and ordered the crewmen to eject at 8,000 feet. Six of them parachuted safely onto the snow and ice, but the seventh never got out of the plane and was killed as the B-52 crashed in a huge fireball.

“The plane had just been re-tanked in the air and contained 124,000 pounds of fuel,” said Lars Melgard, a Copenhagen librarian who operates a public archive on nuclear power and nuclear weapons. “People inside the barracks at Thule lost their footing from the shock wave.”

The huge fire consumed all four of the bombs aboard the plane without detonating them.

There were also political shock waves. News of the crash--and the bombs--outraged the Danes, who happened to be holding an election the day after the crash. The foreign minister reminded Washington that by treaty, the United States had the right to operate a base in Greenland but not to ferry nuclear bombs over Danish territory.

The Soviet ambassador to Washington, meanwhile, appeared at the State Department with a memorandum complaining about “dangerous and even provocative flights” that violated “generally accepted principles and international law.”

And at the Pentagon, Defense Secretary Robert S. McNamara took stock of the situation and swiftly ordered all nuclear bombs taken off the Chrome Dome planes.

Later that year, he grounded the operation completely, shifting the United States’ reliance to land-based intercontinental nuclear missiles.

The Thule crash, after all, was the second major accident in two years involving B-52s, nuclear weapons and civilians.

In 1966, a B-52 on the Mediterranean Chrome Dome route tried to refuel at high altitude and collided with its tanker plane. Both planes crashed near Palomares, Spain, and two of the B-52’s four nuclear bombs underwent the conventional explosion that is the first step of a nuclear bomb blast. Although there was no nuclear detonation, the conventional blast alone sprayed the bombs’ radioactive material over a populated area.

And there were other incidents involving U.S. nuclear bombers during the Cold War--never a full-fledged nuclear detonation, but fires, non-nuclear explosions and radioactive contamination.

Nuclear weapons carry safety features designed to prevent an accidental nuclear blast. But because the bombs contain conventional explosives, in addition to nuclear material, they can undergo lesser, conventional detonations and shower an area with radioactive material.

First to the wreck near Thule were Greenlanders, small groups of Inuit hunters with their dog sleds, who mushed to the crash site to look for survivors. Soon after came hundreds of U.S. military personnel, far better equipped than the Greenlanders, with bulldozers, cranes, anti-radiation “moon suits” and Geiger counters.

The military personnel quickly set about picking up fragments of the ruined aircraft, identifying what bits of the bombs could still be found after the fire and scraping up vast quantities of contaminated snow and ice, which was sent back to the United States for treatment and storage.

No one today knows who gave the order, but at some point several hundred of the Danish support staff at the base--civilian truck drivers, construction workers, cooks and the like--were asked to step in and help clean up the wreckage of the top-secret military plane.

One of them was Ole Markussen, who returned to Denmark proper after his stint in Greenland, married Sally Schnell and by the early 1970s began to fall seriously ill.

“It started with getting tired easily, catching colds easily and then a bad stomach,” Schnell said. “He thought, ‘Oh, I’m catching the flu.’ But each day it got a little bit worse.”

Markussen died a slow and painful death, and Schnell nursed him for years, growing frustrated that no one could explain to her satisfaction why his body and mind were falling apart. She refused to accept the Danish government’s position--before the new documents came out--that the Thule workers’ health problems must be the result of the rowdy, alcohol- and tobacco-laced lifestyle typical on Arctic military bases and construction sites.

Markussen’s death certificate lists a hole in his stomach as the cause of death, Schnell said, but she wants to know how it came to be there. “I think his problems came from inhaling the radioactive air--plutonium or whatever else was released,” she said.

Although the new documents do not shed clear light on just which airborne toxic matter Markussen and his colleagues might have inhaled, they do show that about six kilograms of plutonium were aboard the B-52--and that only 2.2 to 3.9 kilograms of plutonium were retrieved from the ice and brought back to the United States.

“We seem to have a lot of plutonium unaccounted for,” Melgard said. “I don’t like plutonium unaccounted for on Danish territory.” He and Schnell are both angry at their government’s willingness to accept Washington’s previous assurances that all was well.

Tybjerg, the governmental adviser, said the newly released documents have also raised questions about what non-nuclear, chemical poisons may have been released into the atmosphere when the plane crashed and its fuel tanks exploded and burned.

Schnell admitted that the thought of yet another round of medical tests makes her impatient. Sometimes, she said, she wishes the government would just release the compensation money she and the other Thule workers are asking for--about $100,000 apiece.

But on the other hand, she said, the thought that the forthcoming medical tests may yield new information gives her hope.

“I’m not just doing this for the (compensation) money,” she said. “I want the information, for doctors and scientists, so that they can give better treatment to people. I never expected anyone to be able to make my husband well again, but I wish they could have made it possible for him to have had a more dignified life.”