Rocky Flats is a gravelly, narrow floodplain cut by gullies as it slopes from the Rocky Mountain foothills into the plains just northwest of Denver. Unlike many places, its name is known more for what was manufactured there than for its geology. Today it is a national wildlife refuge, but for nearly four decades it was a major hub in the nation’s nuclear weapons industrial complex.
During the Cold War nuclear arms race that began after World War II, the US government in 1951 established a major nuclear weapons factory complex at Rocky Flats, located between Golden and Boulder just east of Highway 93. Its purpose was to process plutonium into metal and to manufacture plutonium bomb cores – the successors to the kind of fission bomb that destroyed the Japanese city of Nagasaki in 1945. Dow Chemical Corporation won the contract to operate the plant like a business, only this one was top secret.
With a workforce that often topped 5,000 during its four decades of production, Rocky Flats was one of the Denver area’s largest employers and over the years contributed billions of dollars to the local economies of Arvada and other suburbs in the west metro area. But the plant complex – consisting of eight major production buildings and several hundred support buildings, including a fire department – was dangerous, particularly for the men and women who worked in the production buildings. Because of the radioactive materials the plant worked with, it also posed a danger to the community – most vividly during a plutonium fire in 1969 that almost got out of control and would have contaminated the entire Denver area.
Rocky Flats was able to meet its main goal of producing plutonium bomb cores – 70,000 in all – to enable the US government to pursue a national security policy called deterrence. That risky policy holds that a country must build nuclear weapons of mass destruction to deter another country from using its own nuclear weapons out of fear of retaliation. While that policy is getting a second look today after significant reductions in nuclear arsenals it dominated the Cold War era and brought the world close to nuclear catastrophe during the 1962 Cuban Missile Crisis. Still, the work at Rocky Flats was deemed so important that in 1998 the site was added to the National Register of Historic Places for its historical significance to the United States. In 2005, following a $7 billion cleanup, most of the ten-square-mile site was designated a national wildlife refuge.
Rocky Flats contributed significantly to US history because the plant worked with one of the most important elements on Earth – plutonium. This heavy element is dangerous in any quantity. On the atomic level, plutonium 239, the main ingredient for bombs, is unstable and emits alpha particle radiation that can cause cancer by entering the body through inhalation or a wound. Rocky Flats machined plutonium and other material into hollow bomb cores about the size of misshapen grapefruits that weighed about six pounds each. The core was then surrounded with conventional explosives at a plant in Texas and made ready for a detonation that caused a nuclear chain reaction and an explosion equivalent to about 20,000 tons of TNT.
Originally stand-alone bombs like the one that destroyed Nagasaki, plutonium bombs soon came to be used to detonate much more powerful thermonuclear weapons. Officials often referred to these plutonium detonators as “triggers,” a euphemism that gave rise to the popular claim that Rocky Flats made “nuclear triggers,” a term that obscures the fact that the plant manufactured nuclear weapons of mass destruction.
Plutonium possesses some rare characteristics. It is one of only two elements (the other being uranium 235) whose nuclei can be split, or fissioned, with the resulting chain reactions creating tremendous explosions on the scale of Albert Einstein’s famous formula that E = MC² (energy equals mass times the speed of light squared). Another characteristic is that when plutonium burns, the ash it creates can be reprocessed, the proverbial phoenix from the ashes. And plutonium burned a lot at Rocky Flats, threatening both workers and the communities outside the plant. The reason is that in some forms – especially chips or flecks – plutonium is pyrophoric, meaning it ignites spontaneously in air. Documents show that the plutonium production areas at the factory experienced hundreds of fires over the years. Most were small and easily doused by workers.
The largest and most dangerous fire at the plant occurred on Mother’s Day in May 1969. Plutonium-flecked oily rags ignited spontaneously and the fire, by burning other flammable materials, spread throughout a cavernous production building containing 7,641 pounds of plutonium. Courageous firefighting and luck saved the building’s roof from burning through. General Edward Giller, a top Atomic Energy Commission official, reported to Congress in 1970 that the fire came close to contaminating hundreds of square miles. Had the fire been any bigger, he said, it may not have been containable.
Raid and Shutdown
Managers at Rocky Flats did not always follow the rulebook in making decisions. In 1952, for example, they settled a dispute with rancher Marcus Church by giving him keys to fence locks and allowing him to move cattle through the top-secret plant. “Cattle can’t talk,” one employee said, noting that Church only moved his cattle a few times. “Nobody said anything, although it didn’t get back to Washington, where they’d make a big deal out of it.” The Old West and the New West were making accommodations.
Other management decisions were not so humorous. Many had to do with the disposal of large amounts of nuclear and toxic chemical waste created during the production process. The plant’s top priority was producing bomb cores, so the waste that could not be shipped off the site immediately was simply buried or stored outside in ponds or in metal barrels that leaked. Such environmentally unsound practices in industries around the nation came under increasing scrutiny after the Environmental Protection Agency (EPA) was established in 1970. But weapons plants such as Rocky Flats claimed they were exempt from such jurisdiction because of the Atomic Energy Act of 1954.
That immunity argument worked until challenged in court during the mid-1980s, at about the same time whistleblowers informed FBI officials of potentially illegal practices at Rocky Flats. A whistleblower was also the source for newspaper stories in 1987 about a metal/woodworking shop at the plant making items for private use such as medallions, staircases, and foot massagers. An atmosphere of wrongdoing, along with reports from EPA regulators, contributed to the FBI-EPA raid on the plant on June 6, 1989, to find evidence of environmental crimes. This dramatic, if symbolic, raid occurred as the Cold War nuclear arms race was winding down and federal priorities were shifting toward environmental protection and away from nuclear weapons production. Indeed, in November 1989, five months after the raid and the same month the Berlin Wall fell, plutonium operations at Rocky Flats were halted.
A little more than two years later, President George H.W. Bush declared the plant’s weapons-making mission over, and cleanup began. The contaminated site was cleaned up enough so that most of the land was transferred from the US Department of Energy (DOE) to the US Fish and Wildlife Service as a national wildlife refuge in 2007. But DOE retained ownership of about 1,300 acres, 20 percent of the area, in the most contaminated central industrial section of the plant site. As of 2014, the refuge, with its planned biking and hiking trails, had not been opened to the public for what the US Fish and Wildlife Service said are financial reasons.
The significance of the Rocky Flats complex can be seen largely through its legacies: the bombs it manufactured, its former workers, the environment, and the community. On a national level, the hollow plutonium bomb cores made at Rocky Flats are present in the US nuclear arsenal, which in 2014 amounted to 7,700 weapons (of the 17,300 nuclear weapons possessed by nine nations around the world, Russia has the largest number, with 8,500).
The US plutonium bombs were produced by the more than 20,000 men and women who worked at Rocky Flats over the years, some of them for decades. Most are proud of the work they did, although many were stung by antinuclear protestors outside the plant who called them names such as “murderers.” Many workers are happily retired, while others suffer from illnesses caused or suspected to have been caused by their former jobs. For example, chronic beryllium disease, similar to black lung disease, definitely killed or sickened a few hundred plant workers. Cancer, a disease whose origins are harder to pinpoint, has afflicted many workers – some of whom died while others continue to fight for health compensation.
It is clear from various studies that radiation contamination from Rocky Flats went off the site, but the significance is still disputed. On-site contamination is indisputable. Rockwell International Corporation took over from Dow in 1975 as the plant’s contractor. In 1992, following the FBI-EPA raid, Rockwell settled a criminal action proceeding by the government by pleading guilty to ten environmental crimes and agreeing to pay a fine of $18.5 million. Some members of the grand jury investigating the case, along with activists and other citizens, complained that the settlement was not tough enough.
The record shows that Rocky Flats was a secretive, dangerous industrial complex, particularly as it aged. By the 1980s, the major plutonium-processing building had far exceeded its designed lifetime. Publicity about the plant, both before and after the 1989 raid, made it seem sinister. Many people in nearby communities continue to wonder aloud whether radiation from the plant caused the illnesses or deaths of friends or relatives. State health department data, such as the cancer registry, do not support such fears, but they still persist. Uncertainty, risk, and evidence are weighed differently by various individuals and groups. For example, antinuclear activists often see danger because of the unknowns, while many officials see the available data and information as demonstrating that risks are negligible. The debate is sure to continue after the national wildlife refuge is opened to the public.