Rocky Flats
Historical Public Exposures Studies

Background

Project Overview

Researchers identified radioactive materials and chemicals released between 1952 and 1989 from the former Rocky Flats Nuclear Weapons Plant as part of the nine-year Historical Public Exposures Studies on Rocky Flats. The plant, which is owned by the U.S. Department of Energy (DOE), is now known as the Rocky Flats Environmental Technology Site. The purpose of the studies was to determine potential cancer risks to residents living in surrounding communities resulting from the contaminants released off the site.

Activities at Rocky Flats included processing, purifying, machining and preparing plutonium for the manufacture of pits, the key component of what became known as "triggers" for nuclear weapons. The plant also manufactured other weapons parts using uranium, beryllium, stainless steel and other materials. The parts were shipped to Texas where the nuclear weapons were assembled. In addition, plutonium was reprocessed, or recycled, from retired warheads. Plutonium operations at Rocky Flats were suspended in late 1989 and never resumed. The DOE officially ended nuclear weapons production at the plant in 1992.

Rocky Flats is located 16 miles northwest of downtown Denver in northern Jefferson County. The site includes a 350-acre industrial area surrounded by 6,100 acres of open space, called the "buffer zone."

Former Colorado Governor Roy Romer and Admiral James Watkins, then-Secretary of the DOE, signed an Agreement in Principle in June 1989 providing the state of Colorado with the funding for health-related studies and other Rocky Flats oversight activities.

The Colorado Department of Public Health and Environment invited national scientific experts to help design the research. To increase public accountability, the experts recommended the research be done in two phases by two different contractors.

Phase I of the Historical Public Exposures Studies, a dose reconstruction and toxicologic review, began in 1990. ChemRisk, a division of McLaren/Hart Environmental Engineering, conducted Phase I. Radiological Assessments Corporation conducted Phase II, a toxicity assessment and risk characterization, from 1992 to 1999.

Project Administration and Oversight

The Rocky Flats Historical Public Exposures Studies project was administered by the Colorado Department of Public Health and Environment and overseen by a 12-member Health Advisory Panel appointed by former Governor Roy Romer.

The Health Advisory Panel provided independent scientific oversight for contractors conducting the Historical Public Exposures Studies and facilitated public participation in the process. Panel members were selected to represent a wide range of interests, affiliations and expertise. Some panel members were selected based on their scientific expertise--toxicology, epidemiology, risk assessment, meteorology, environmental modeling, medicine and radiation health physics. Other members were chosen based on their community connections--a resident who lived near Rocky Flats and a local government official.

Government agencies represented during the studies included the Colorado Department of Public Health and Environment, the DOE and the U.S. Environmental Protection Agency.