The Rocky Flats Plant was a United States manufacturing complex that produced nuclear weapons parts near Denver, Colorado.Colorado Department of Public Health and Environment, Rocky Flats Site, Frequently asked questions about Rocky Flats. The facility's primary mission was the fabrication of plutonium pits, the fissionable part of a bomb that produces a nuclear explosion. The pits were shipped to other facilities to be assembled into complete nuclear weapons.What is the history of Rocky Flats?. Colorado Gov., 2011 Operated from 1952 to 1992 by private contractors Dow Chemical Company, Rockwell International Corporation and EG&G, the complex was under the control of the U.S. Atomic Energy Commission (AEC), succeeded by the Department of Energy (DOE) in 1977. The plant manufactured 1,000 to 2,000 pits per year.
Plutonium pit production was halted in 1989 after EPA and FBI agents raided the facility and the plant was formally shut down in 1992. Rockwell then accepted a plea agreement for criminal violations of environmental law. At the time, the fine was one of the largest penalties ever in an environmental law case.
Cleanup began in the early 1990s, and the site achieved regulatory closure in 2006. The cleanup effort decommissioned and demolished the entire plant, removing more than 800 structures, over 21 tons of weapons-grade material, over 1.3 million cubic meters of waste, and treated more than of water. Four groundwater treatment systems were also constructed.Colorado Department of Public Health and Environment, Rocky Flats, Site History, https://cdphe.colorado.gov/hm/rocky-flats-site-history The site of the former facility consists of two distinct areas: the "Central Operable Unit", which remains off-limits to the public as a CERCLA Superfund site, owned and managed by the U.S. Department of Energy,U.S. Department of Energy, Rocky Flats, http://www.lm.doe.gov/Rocky_Flats/Sites.aspx and the Rocky Flats National Wildlife Refuge, owned and managed by the U.S. Fish and Wildlife Service.U.S. Fish and Wildlife Service, Rocky Flats Wildlife Refuge, https://www.fws.gov/refuge/rocky_flats/ Every five years, the U.S. Department of Energy, U.S. Environmental Protection Agency, and Colorado Department of Public Health and Environment review environmental data and other information to assess whether the remedy is functioning as intended.U.S. Environmental Protection Agency, https://cumulis.epa.gov/supercpad/cursites/dsp_ssppSiteData1.cfm?id=0800360#Why The latest Five-Year Review for the site, released in August 2022, concluded the site remedy is protective of human health and the environment. However, a protectiveness deferred determination was made for PFAS.U.S. Department of Energy, Legacy Management, Update on Rocky Flats Five-Year Review, https://energy.gov/lm/articles/update-rocky-flats-cercla-five-year-review
History
1950s
Following World War II, the United States increased production of nuclear weapons. A site about northwest of Denver on a windy plateau called Rocky Flats was chosen for the facility. Contemporary news reports stated that the site would not be used to produce nuclear bombs, but might be used to produce uranium and plutonium components for use in nuclear weapons.
The construction of Rocky Flats began in July 1951 and was a significant boon to the Colorado economy. Colorado state highways 72 and 93 were constructed to access the plant. Direct government construction contracts to Colorado business were worth $26 million and employed 2,800 people.
By April 1953, the plant began operating under Dow Chemical company. What the plant made, when construction was finished, when it began making its products, and how much product it was making was secret. Routine production processes began immediately leaking plutonium into the atmosphere. A later study on the risks to public health from Rocky Flats estimated that normal operations leaked up to 130,000 microcuries of plutonium annually into the atmosphere as part of its production processes during the 1950s. This routine leakage declined in the 1960s and continued down to 60 picocuries in 1989. For residents living in the area most contaminated by Rocky Flats, this is a comparable exposure to the plutonium from fallout of nuclear weapons testing. This does not include the much higher levels of exposure as a result of the later fires.
Rocky Flats was established next to Walnut Creek and Woman Creek. Until the construction of a waste treatment facility in 1957, plutonium contaminated wastewater was discharged directly into Walnut Creek which flowed into Broomfield's drinking water supply. In 1953, a retention pond was built along Walnut Creek which accumulated plutonium in its soil. In addition to plutonium and uranium contamination, the pond absorbed chemicals used in the production process such as algicides and chromates. Sewer water was originally designed to route to trenches on the property. The original wastewater system was not 100% isolated from the sewer, resulting in the trenches also being contaminated with uranium and plutonium. These trenches filled up in 1968.
The AEC called Rocky Flats a "Weapon Production Facility" in a 1956 report. At this time, the plant was expanded with an additional $18.4 million investment from the AEC.
In June 1957 two employees were taken to the onsite hospital after an explosion in the production line. They were treated for cuts from flying glass and exposure to plutonium.
On September 11, 1957, a plutonium fire occurred in one of the gloveboxes used to handle radioactive materials, igniting the combustible rubber gloves and plexiglas windows of the box. Metallic plutonium is a fire hazard and pyrophoric; under the right conditions it may ignite in air at room temperature. The fire escaped containment in under thirty minutes and the firefighters were forced to use water, a risky decision on plutonium fire, to put out the fire in the glovebox. After putting out the original source, there was an explosion in the ventilation system. The fire burned the filters that normally removed the plutonium from the building's air resulting in the release of 21 curies of plutonium into the atmosphere. For comparison the Fat Man, used 448 curies of plutonium for its core. The accident resulted in the contamination of Building 771 and caused $818,600 in damage. At the time, the AEC spokesman significantly downplayed the risk of plutonium exposure and estimated only $50,000 in damages.
An incinerator for plutonium-contaminated waste was installed in Building 771 in 1958. The offgas was treated with scrubbers and filters and eventually released to the atmosphere. The ash was occasionally able to be reprocessed for plutonium recovery.
1960s
In 1960, one of the workers who responded to the 1957 fire petitioned the state legislature to create a way for workers that receive unsafe doses of radiation on the job to be compensated for the health effects. Smaller incidents, such as a 1962 fire, continued to threaten the safety of the workers without posing a significant public health risk.
Throughout the 1960s, the plant continued to enlarge and add buildings. The AEC sponsored $4.5 million in new construction contracts at Rocky Flats for 1960 and $3 million in 1962 . Payroll reached $26 million annually by 1962.
The 1960s also brought more contamination to the site. By 1967, of plutonium-contaminated lubricants and solvents had accumulated on Pad 903. A large number of them were found to be leaking, and low-level contaminated soil was becoming wind-borne from this area. At least some of the leakage had been detected as early as 1962. From 1954-1970, radioactive waste, including the barrels, was moved to Idaho National Laboratory. After removing the barrels, it was discovered that the winds, which frequently exceeded 100mph, had moved plutonium contaminated soil off the 903 Area. It was then paved over with asphalt in 1969 to prevent further spread of the contaminated soil. Later analysis completed in 1999 for the CDPHE estimated that between 6 and 58 curies of plutonium spilled on to Pad 903 soil due to barrel leakage.
In 1965, there were at least 24 fires at the plant. In the worst of these, 400 employees were exposed to airborne plutonium. Twenty-five workers received over seventeen times the federal limit for plutonium exposure.
In 1968, Dow Chemical covered up leaks of tritium through the plant's smokestack. They chose not install an alarm system to notify the plant of ongoing leakage of radioactive material. In 1972 the AEC disclosed information about these leaks to the public. However, the details as to why there was tritium at Rocky Flats in the first place were classified and remained classified at least through 1992.
Mother's Day 1969 Fire
On May 11, 1969, there was a major fire in a glovebox in Building 776/777. Later investigations disagree on what caused the fire and what time it began. The 1999 report for the Colorado Department of Public Health and Environment said the fire was started around 2pm by a pressed plutonium block which spontaneously ignited. This agrees with some contemporary accounts and the AEC's position. Other fire investigators said the fire was started around 10am by plutonium-contaminated oil rags, and the AEC buried that information to protect individuals from liability. Given the fire crew's experience with the 1957 fire, the fire captain again determined to use water to put out the fire. After six hours the fire was extinguished. The AEC commended the heroism of the firefighters. As in the 1957 fire, the air filters which normally removed plutonium from the building's exhaust were destroyed by the fire, and in this case between 10 and 60 mCi of plutonium was released.
This was likely the costliest industrial accident to occur in the United States up to that time. Approximately $20 million of plutonium was consumed in the fire and there were $50 million of other damages. Congress granted $45 million of the funding for the repairs in an emergency, closed door session at the AEC's request. Cleanup from the accident took two years. Much of the plutonium was recovered during the cleanup.
The U.S. congress ordered an investigation into the accident, which found government officials helped cover up details of the fire by abusing classified information protocols. National Center for Atmospheric Research scientists stated that plant officials also misled the public in press statements about the size and damage from the fire. Dow Chemical employees falsely claimed that their air filtration systems continued to work during the fire and no plutonium was released into the atmosphere. The investigation also found that the AEC ignored safety recommendations after the 1957 fire which may have prevented this accident. The investigation recommended extensive improvements to the building to increase safety. AEC officials such as Major General Giller and Chairman Glenn Seaborg publicly emphasized the need to keep Rocky Flats running and not allow the damage from the fire to delay the Safeguard Program. Senator Robert Byrd highlighted the interdependence of the AEC sites such as Los Alamos, Hanford, and Rocky Flats. Only at the end of the 1400 page congressional testimony did the government recognize that the fire had halted all US nuclear weapons production capability. Leo Goodman, a consultant for the United Auto Workers, criticized Seaborg's leadership of the AEC because Seaborg owned the patent on the discovery of plutonium and was profiting off the AEC's plutonium production.
1970s
In 1970, some members of the public with scientific backgrounds formed the Colorado Committee for Environmental Information to seek information about the public health impact of Rocky Flats. They encouraged the AEC to relocate the plant, but the AEC rejected the idea on the basis that the cost of at least $500 million was unacceptable.