Radioactive contamination from the Rocky Flats Plant
Encyclopedia
]
The Rocky Flats Plant
, a former a U.S. nuclear weapon
s production facility in the state of Colorado, caused radioactive contamination within and outside its boundaries and also produced "area-wide contamination of the Denver
area." The contamination resulted from decades of emissions, leaks and fires that released radioactive isotope
s, largely plutonium
(Pu-239), into the environment. The plant was located about 15 miles upwind from Denver and has since been shut down and its buildings demolished and completely removed from the site.
According to a scientific study, "In the more densely populated areas of Denver, the Pu contamination level in surface soils is several times fallout", and the plutonium contamination "just east of the Rocky Flats plant ranges up to hundreds of times that from nuclear tests."
As noted in a scientific journal, "Exposures of a large population in the Denver area to plutonium and other radionuclides in the exhaust plumes from the plant date back to 1953." Moreover, in 1957 there was a major Pu-239 fire at the plant, followed by another major fire in 1969. Both of these fires resulted in this radioactive material being released into the atmosphere, with the then-secret 1957 fire being the more serious of the two. The contamination of the Denver area by plutonium from these fires and other sources was not reported until the 1970s, and as of 2011 the U.S. Government continues to withhold data on post-Superfund
cleanup contamination levels.
Elevated levels of plutonium have been found in the remains of cancer victims living near the Rocky Flats site, and breathable plutonium outside the former boundaries of the plant was found in August 2010. No government studies of the plutonium contamination and its effect on health are being held as of 2011, and private groups and researchers remain concerned about long-term consequences of the contamination.
After operating for 40 years, only ending after great public protest and a combined Federal Bureau of Investigation
(FBI) and United States Environmental Protection Agency
(EPA) raid in 1989 that stopped production, the Rocky Flats Plant was declared a Superfund
site in 1989 and began its transformation to a cleanup site in February 1992. Removal of the plant and surface contamination was largely completed in the late 1990s and early 2000s. Nearly all underground contamination was left in place in order to reduce costs to the U.S. Government, which provided liability indemnification to the defense contractors that operated the plant.
the Rocky Flats Plant
nuclear weapons production facility was built with high security conditions by the U.S. Government -- but without consulting local or state authorities for permission -- about 15 miles to the northwest of Denver. Throughout the 1950s and 1960s, only employees knew of the work being done there, and even they had only a working knowledge of their specific responsibilities. The general public was kept entirely uninformed.
Plutonium
, used to construct the weapons' fissile component, can spontaneously combust at room temperatures in air. Major plutonium fires in 1957 and 1969 occurred at Rocky Flats and spread radioactive contamination in the Denver metropolitan area. Isopleth diagrams from scientific studies show the city of Denver included in the area where surface sampling detected plutonium.
Estimates for the amount of plutonium released to the environment from the major fires vary between tens of grams to hundreds of kilograms. Hundreds of other small plutonium fires and intentional incinerations also occurred at Rocky Flats that were not nearly as destructive.
As documented in FBI reports and court records, FBI agents and prosecutors became aware that Rockwell workers had been mixing hazardous and other wastes with concrete to create one-ton solid blocks called pondcrete
. These were stored in the open under tarps on asphalt pads. The workers had also directed liquid contamination into a series of holding ponds, even after regulators had closed the ponds due to ground-water contamination. Liquid from the sewage plant, meanwhile, had been "spray irrigated" over fields via sprinklers, mainly to avoid the cost --and the regulatory and public reviews -- that would come from directly discharging the contaminated waste into creeks.
The pondcrete turned out to be weak storage. Relatively unprotected from the elements, the blocks began to leak and sag. Nitrates, cadmium and low-level radioactive waste -- some of which with a 24,000-year half-life -- began to leach into the ground and run downhill toward Walnut Creek and Woman Creek. There they would sometimes meet the liquids from the sprinklers, for they also had run-off that flowed into the creeks.
Most of the plutonium from Rocky Flats was oxidized plutonium, which does not readily dissolve in water. In terms of waterborne Pu-239 contamination, a large portion of the plutonium released into the creeks sank to the bottom and is now found in the streambeds of Walnut and Woman Creeks, and on the bottom of local public reservoirs just outside of Rocky Flats: Great Western Reservoir, no longer used for city of Broomfied consumption as of 1997, and Standley Lake
, a drinking water supply for the cities of Westminster, Thornton, Northglenn and some residents of Federal Heights.
Additionally, thousands of 55-gallon drums of nuclear waste from milling operations were stored outside in an unprotected earthen area called the 903 pad storage area, where they corroded and leaked radionuclides over years into the soil and water. An estimated 5,000 gallons of plutonium-contaminated oil leached into the soil between 1964 and 1967. Portions of this high-level radioactive waste became airborne in the heavy winds of the Front Range
, with Denver being downwind.
An early, focused study by Dr. Carl Johnson, health director for Jefferson County, showed a 45 percent increase in congenital birth defects in Denver suburbs downwind of Rocky Flats compared to the rest of Colorado. Moreover, he found increased cancer rates for those living closer to the plant, and he estimated 491 excess cancer cases whereas the DOE
estimated one. Real estate interests pressed the county to fire Johnson, claiming his findings hurt their industry. After electing a real estate investor to the county board, they succeeded.
Additional individual radiological victims directly related to Rocky Flats are featured in the film Dark Circle. These include Rocky Flats employee and brain cancer victim Don Gabel (who died during filming), Beth Campbell and Ruth Wiebe. The dramatic effects on the livestock of rancher Lloyd Mixom are also discussed.
, and the Superfund remediation of Rocky Flats did not include offsite areas, nor Denver, nor its suburbs. U.S. Government efforts to make the area surrounding the former plant into the Rocky Flats National Wildlife Refuge
have been controversial due to the pervasive contamination, much of which is underground and not remediated.
officials told the Denver Post that the fire “resulted in no spread of radioactive contamination of any consequence.” The public was not informed of substantial contamination from the 1957 plutonium fire until after the highly visible 1969 fire, when civilian monitoring teams confronted government officials with measurements made outside the plant of radioactive contamination suspected to be from the 1969 fire, which consumed hundreds of pounds of plutonium (850 kg).
The 1969 fire raised public awareness of potential hazards posed by the plant and led to years of increasing citizen protests and demands for plant closure.
Despite plutonium incineration and hundreds of accidental fires that began in the 1950s, including the major plutonium fires of 1957 and 1969, airborne-become-groundborne radioactive contamination extending well beyond the Rocky Flats plant was not publicly reported until beginning in the 1970s by way of isopleth maps showing the contamination in millicuries of plutonium per square kilometer (Carl J. Johnson, Cancer Incidence in an Area Contaminated with Radionuclides Near a Nuclear Installation, AMBIO, 10, 4, October 1981, page 177 and Table 3).
Independent researchers also discovered cesium-137 and strontium-90 near the Rocky Flats plant, providing evidence that each of the major fires and explosions in 1957 and 1969 had involved a criticality accident
. Rocky Flats officials denied that criticality had ever taken place at the facility. In the 1957 fire an explosion occurred in the ventilation system whose filters had initially trapped a good deal of escaping plutonium oxide before they were in turn destroyed, releasing Pu-239 to the atmosphere. The 1969 fire "also burned through the filters in the building's exhaust system, and witnesses reported that plutonium-contaminated smoke rose into the atmosphere from a ventilation duct on the roof."
The Rocky Flats Plant
Rocky Flats Plant
The Rocky Flats Plant was a United States nuclear weapons production facility near Denver, Colorado that operated from 1952 to 1992. It was under the control of the United States Atomic Energy Commission until 1977, when it was replaced by the Department of Energy .-1950s:Following World War II,...
, a former a U.S. nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
s production facility in the state of Colorado, caused radioactive contamination within and outside its boundaries and also produced "area-wide contamination of the Denver
Denver, Colorado
The City and County of Denver is the capital and the most populous city of the U.S. state of Colorado. Denver is a consolidated city-county, located in the South Platte River Valley on the western edge of the High Plains just east of the Front Range of the Rocky Mountains...
area." The contamination resulted from decades of emissions, leaks and fires that released radioactive isotope
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
s, largely plutonium
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...
(Pu-239), into the environment. The plant was located about 15 miles upwind from Denver and has since been shut down and its buildings demolished and completely removed from the site.
According to a scientific study, "In the more densely populated areas of Denver, the Pu contamination level in surface soils is several times fallout", and the plutonium contamination "just east of the Rocky Flats plant ranges up to hundreds of times that from nuclear tests."
As noted in a scientific journal, "Exposures of a large population in the Denver area to plutonium and other radionuclides in the exhaust plumes from the plant date back to 1953." Moreover, in 1957 there was a major Pu-239 fire at the plant, followed by another major fire in 1969. Both of these fires resulted in this radioactive material being released into the atmosphere, with the then-secret 1957 fire being the more serious of the two. The contamination of the Denver area by plutonium from these fires and other sources was not reported until the 1970s, and as of 2011 the U.S. Government continues to withhold data on post-Superfund
Superfund
Superfund is the common name for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 , a United States federal law designed to clean up sites contaminated with hazardous substances...
cleanup contamination levels.
Elevated levels of plutonium have been found in the remains of cancer victims living near the Rocky Flats site, and breathable plutonium outside the former boundaries of the plant was found in August 2010. No government studies of the plutonium contamination and its effect on health are being held as of 2011, and private groups and researchers remain concerned about long-term consequences of the contamination.
After operating for 40 years, only ending after great public protest and a combined Federal Bureau of Investigation
Federal Bureau of Investigation
The Federal Bureau of Investigation is an agency of the United States Department of Justice that serves as both a federal criminal investigative body and an internal intelligence agency . The FBI has investigative jurisdiction over violations of more than 200 categories of federal crime...
(FBI) and United States Environmental Protection Agency
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
(EPA) raid in 1989 that stopped production, the Rocky Flats Plant was declared a Superfund
Superfund
Superfund is the common name for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 , a United States federal law designed to clean up sites contaminated with hazardous substances...
site in 1989 and began its transformation to a cleanup site in February 1992. Removal of the plant and surface contamination was largely completed in the late 1990s and early 2000s. Nearly all underground contamination was left in place in order to reduce costs to the U.S. Government, which provided liability indemnification to the defense contractors that operated the plant.
Sources of contamination
During the Cold WarCold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...
the Rocky Flats Plant
Rocky Flats Plant
The Rocky Flats Plant was a United States nuclear weapons production facility near Denver, Colorado that operated from 1952 to 1992. It was under the control of the United States Atomic Energy Commission until 1977, when it was replaced by the Department of Energy .-1950s:Following World War II,...
nuclear weapons production facility was built with high security conditions by the U.S. Government -- but without consulting local or state authorities for permission -- about 15 miles to the northwest of Denver. Throughout the 1950s and 1960s, only employees knew of the work being done there, and even they had only a working knowledge of their specific responsibilities. The general public was kept entirely uninformed.
Plutonium
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...
, used to construct the weapons' fissile component, can spontaneously combust at room temperatures in air. Major plutonium fires in 1957 and 1969 occurred at Rocky Flats and spread radioactive contamination in the Denver metropolitan area. Isopleth diagrams from scientific studies show the city of Denver included in the area where surface sampling detected plutonium.
Estimates for the amount of plutonium released to the environment from the major fires vary between tens of grams to hundreds of kilograms. Hundreds of other small plutonium fires and intentional incinerations also occurred at Rocky Flats that were not nearly as destructive.
As documented in FBI reports and court records, FBI agents and prosecutors became aware that Rockwell workers had been mixing hazardous and other wastes with concrete to create one-ton solid blocks called pondcrete
Pondcrete
Pondcrete is a mixture of cement and sludge. Its role is to immobilize hazardous waste and, in some cases, lower-level radioactive waste, in the form of solid material...
. These were stored in the open under tarps on asphalt pads. The workers had also directed liquid contamination into a series of holding ponds, even after regulators had closed the ponds due to ground-water contamination. Liquid from the sewage plant, meanwhile, had been "spray irrigated" over fields via sprinklers, mainly to avoid the cost --and the regulatory and public reviews -- that would come from directly discharging the contaminated waste into creeks.
The pondcrete turned out to be weak storage. Relatively unprotected from the elements, the blocks began to leak and sag. Nitrates, cadmium and low-level radioactive waste -- some of which with a 24,000-year half-life -- began to leach into the ground and run downhill toward Walnut Creek and Woman Creek. There they would sometimes meet the liquids from the sprinklers, for they also had run-off that flowed into the creeks.
Most of the plutonium from Rocky Flats was oxidized plutonium, which does not readily dissolve in water. In terms of waterborne Pu-239 contamination, a large portion of the plutonium released into the creeks sank to the bottom and is now found in the streambeds of Walnut and Woman Creeks, and on the bottom of local public reservoirs just outside of Rocky Flats: Great Western Reservoir, no longer used for city of Broomfied consumption as of 1997, and Standley Lake
Standley Lake
Standley Lake is a lake located in Westminster, Colorado. The lake serves as a reservoir and is also used for recreation. It is the prominent feature of the surrounding Standley Lake Regional Park....
, a drinking water supply for the cities of Westminster, Thornton, Northglenn and some residents of Federal Heights.
Additionally, thousands of 55-gallon drums of nuclear waste from milling operations were stored outside in an unprotected earthen area called the 903 pad storage area, where they corroded and leaked radionuclides over years into the soil and water. An estimated 5,000 gallons of plutonium-contaminated oil leached into the soil between 1964 and 1967. Portions of this high-level radioactive waste became airborne in the heavy winds of the Front Range
Front Range
The Front Range is a mountain range of the Southern Rocky Mountains of North America located in the north-central portion of the U.S. State of Colorado and southeastern portion of the U.S. State of Wyoming. It is the first mountain range encountered moving west along the 40th parallel north across...
, with Denver being downwind.
Effects on health
Despite the fact that elevated levels of plutonium have been found in deceased bone-cancer victims such as 11 year-old Kristen Haag, whose home was six miles away from Rocky Flats, related long-term health studies for the general population of the Greater Denver Metropolitan Area do not exist and are not on-going as of 2011.An early, focused study by Dr. Carl Johnson, health director for Jefferson County, showed a 45 percent increase in congenital birth defects in Denver suburbs downwind of Rocky Flats compared to the rest of Colorado. Moreover, he found increased cancer rates for those living closer to the plant, and he estimated 491 excess cancer cases whereas the DOE
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
estimated one. Real estate interests pressed the county to fire Johnson, claiming his findings hurt their industry. After electing a real estate investor to the county board, they succeeded.
Additional individual radiological victims directly related to Rocky Flats are featured in the film Dark Circle. These include Rocky Flats employee and brain cancer victim Don Gabel (who died during filming), Beth Campbell and Ruth Wiebe. The dramatic effects on the livestock of rancher Lloyd Mixom are also discussed.
Other effects
Denver's automotive beltway to this day lacks for a component in the northwest sector, partly due to concerns over plutonium contamination, which prevailing winds spread over the area during and since the fires. Notably, plutonium has a 24,000-year half-lifeHalf-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
, and the Superfund remediation of Rocky Flats did not include offsite areas, nor Denver, nor its suburbs. U.S. Government efforts to make the area surrounding the former plant into the Rocky Flats National Wildlife Refuge
Rocky Flats National Wildlife Refuge
The Rocky Flats National Wildlife Refuge is a United States National Wildlife Refuge located approximately 16 miles northwest of Denver, Colorado. The site was previously occupied by the Rocky Flats Plant, a nuclear weapons production facility...
have been controversial due to the pervasive contamination, much of which is underground and not remediated.
Reporting of contamination
No radioactivity warning, advisement or cleanup was provided to the public in the 1957 fire, the worse of the two major fires. At the time of the 1957 fire, AECAEC
AEC is a three-letter abbreviation that may refer to:Governance* African Economic Community* ASEAN Economic Community* Asian European Council, a Paris-based non-partisan policy research organization...
officials told the Denver Post that the fire “resulted in no spread of radioactive contamination of any consequence.” The public was not informed of substantial contamination from the 1957 plutonium fire until after the highly visible 1969 fire, when civilian monitoring teams confronted government officials with measurements made outside the plant of radioactive contamination suspected to be from the 1969 fire, which consumed hundreds of pounds of plutonium (850 kg).
The 1969 fire raised public awareness of potential hazards posed by the plant and led to years of increasing citizen protests and demands for plant closure.
Despite plutonium incineration and hundreds of accidental fires that began in the 1950s, including the major plutonium fires of 1957 and 1969, airborne-become-groundborne radioactive contamination extending well beyond the Rocky Flats plant was not publicly reported until beginning in the 1970s by way of isopleth maps showing the contamination in millicuries of plutonium per square kilometer (Carl J. Johnson, Cancer Incidence in an Area Contaminated with Radionuclides Near a Nuclear Installation, AMBIO, 10, 4, October 1981, page 177 and Table 3).
Independent researchers also discovered cesium-137 and strontium-90 near the Rocky Flats plant, providing evidence that each of the major fires and explosions in 1957 and 1969 had involved a criticality accident
Criticality accident
A criticality accident, sometimes referred to as an excursion or a power excursion, is an accidental increase of nuclear chain reactions in a fissile material, such as enriched uranium or plutonium...
. Rocky Flats officials denied that criticality had ever taken place at the facility. In the 1957 fire an explosion occurred in the ventilation system whose filters had initially trapped a good deal of escaping plutonium oxide before they were in turn destroyed, releasing Pu-239 to the atmosphere. The 1969 fire "also burned through the filters in the building's exhaust system, and witnesses reported that plutonium-contaminated smoke rose into the atmosphere from a ventilation duct on the roof."