Nuclear plant releases in Rocky Flats, Colorado
The Rocky Flats nuclear plant, located 26 kilometers northwest of Denver, Colorado, operated from 1952 to 1989 and was involved in the production of nuclear weapons. Throughout its operational history, the plant was associated with several incidents that resulted in low-level radioactive contamination of nearby land and water bodies, posing potential public health risks to the surrounding communities. Notable incidents occurred in 1957, 1969, and 1973, involving the release of plutonium and other radioactive materials due to accidents and improper waste management practices.
The site became infamous for the mishandling of hazardous materials and the environmental risks posed by the storage of contaminated substances. Public concern over safety practices led to investigations, culminating in a significant federal raid in 1989, which revealed extensive violations. Following the closure of the plant, extensive cleanup efforts were undertaken, involving the removal of radioactive waste and the restoration of contaminated areas. By 2005, the cleanup was deemed complete, and the land was eventually repurposed into a national wildlife refuge, which opened to the public in 2018, offering recreational opportunities while emphasizing environmental restoration.
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Nuclear plant releases in Rocky Flats, Colorado
THE EVENTS: Short- and long-term releases from the Rocky Flats nuclear plant in central Colorado that caused low-level radioactive contamination of off-site reservoirs and land areas
DATES: Notable incidents in 1957, 1969, and 1973; other long-term releases during operational years 1952-1989
One of thirteen nuclear weapons production facilities operating in the United States during the Cold War, Rocky Flats was the site of a number of radioactive and toxic releases during its four-decade operational history. Releases from Rocky Flats had the potential to be a major public health hazard because of the facility’s proximity to a large population center.
The Rocky Flats nuclear plant site stands 26 kilometers (16 miles) northwest of downtown Denver. From 1952 to 1989, the plant’s primary mission was to produce nuclear weapon trigger assemblies. This required the machining of plutonium, uranium, beryllium, and other metals. Plutonium was also recovered from obsolete weapons and recycled at the plant. Radioactive americium 241, a decay product of plutonium, was separated and recovered in this process.
Over the four decades of the plant’s operation, emergencies threatened the surrounding and environment. On September 11, 1957, and May 11, 1969, for example, plutonium stored inside glove boxes at the plant spontaneously combusted, allowing plutonium dust and to escape to the outside through the ventilation systems.
During the late 1950’s and the 1960’s more than five thousand drums of oil accumulated on-site that had become contaminated with plutonium and the solvent carbon tetrachloride during machining operations. In 1967 and 1968 the barrels—many of them corroded and leaking—were removed, leaving the soil on which they had stood exposed to the elements. Subsequent windstorms blew the contaminated soil east and southeast of the plant. In 1969 the former storage area was asphalted over to contain the remaining contamination.
In 1973 the radioactive tritium entered the plant’s during plutonium processing. It was discharged in to an on-site holding pond. From there, it entered Walnut Creek, which carried the radioactive to Great Western Reservoir, a source of drinking water for the Colorado of Broomfield. Fortunately, radionuclide concentrations were not detected above levels believed to present a health concern.
Some plant workers went public with their concerns that proper safety guidelines were being disregarded. One infamous example involved a substance known as pondcrete. Until the mid-1980’s the plant discharged hazardous chemical wastes mixed with low-level radioactive wastes to solar ponds to reduce the volume of the wastes through evaporation. Beginning in 1985, as the were being phased out, was dredged from them, mixed with Portland cement, and placed in large plastic-lined cardboard boxes. The pondcrete was supposed to form solid blocks that could be shipped elsewhere for burial, but much of the radioactive, toxic mixture remained mushy. The blocks were stacked in a parking lot and left exposed to the weather for three years, and the decomposing pondcrete was washed into the soil by rain and snowmelt.
Requests from the public for specific information on hazards at the plant were frequently denied by officials, who claimed that such records were classified. A series of investigations finally resulted in a 1989 raid by Federal Bureau of Investigation (FBI) agents and Environmental Protection Agency (EPA) staff, who seized plant records. Evidence of the mishandling of hazardous materials at the plant resulted in an $18.5 million fine for Rockwell International, the company that managed the plant for the U.S. Department of Energy (DOE), and termination of its contract. That same year, Rocky Flats was placed on the National Priorities List (NPL), making it a Superfund cleanup site.
The next management company, EG&G, was also accused of safety violations, despite its expenditure of $50 million on repairs. In 1993, Secretary of Energy James Watkins announced the end of nuclear production at Rocky Flats.
Studies of tissue and urine samples from people living near the plant found that they had received doses much lower than those normally caused by natural background radiation. As part of the cleanup and processes, a new water supply for Broomfield was constructed, along with catch basins and diversion ditches to control contaminated runoff. Radioactive and hazardous chemical wastes, as well as decontaminated construction materials from demolished industrial facilities, were transported off-site to licensed repositories. Still-useful nuclear materials were shipped to other DOE facilities. On-site landfills were covered to meet final closure criteria, and treatment systems were installed as part of the cleanup.
In late 2005, cleanup of chemical and radiological contamination within the 1,619-hectare (4,000-acre) buffer zone surrounding the former plant site was declared complete. The EPA deleted this portion of the Rocky Flats site from the NPL in 2007 and handed the land over to the U.S. Fish and Wildlife Service for use as a national wildlife refuge. The 5,237-acre park began offering hikes in 2015. It fully opened to the public in 2018, offering hiking trails, bicycling, horseback riding, and cross-country skiing.
Bibliography
Ackland, Len. Making a Real Killing: Rocky Flats and the Nuclear West. Albuquerque: University of New Mexico Press, 2002.
Layzer, Judith A. “Government Secrets at Rocky Flats.” In The Environmental Case: Translating Values into Policy. 2d ed. Washington, D.C.: CQ Press, 2006.
Rood, Arthur S., and John E. Till. Estimated Exposure and Lifetime Cancer Incidence Risk from Routine Plutonium Releases at the Rocky Flats Plant: Independent Analysis of Exposure, Dose, and Health Risk to Off-Site Individuals. Neeses, S.C.: Radiological Assessments Corporation, 1999.
"Rocky Flats National Wildlife Refuge." U.S. Fish and Wildlife Service, www.fws.gov/refuge/rocky-flats. Accessed 22 July 2024.
U.S. Department of Energy. Second Five-Year Review Report for the Rocky Flats Site, Jefferson and Boulder Counties, Colorado. Grand Junction, Colo.: Author, 2007.