Important Notice: The Hanford Health Information Network (HHIN) closed in May, 2000. HHIN Web pages are provided as archived information only, and are not currently maintained. Information contained on the HHIN Web pages may be out-of-date.

Current information is available through the Hanford Community Health Project, which is updated by the Agency for Toxic Substances and Disease Registry of the U.S. Centers for Disease Control and Prevention.

The Release of Radioactive Materials from Hanford: 1944-1972

This report presents information on the release of radioactive materials into the environment from Hanford's historical operations (1944-1972). While smaller releases have continued since 1972, the Congressional mandate for the Hanford Health Information Network (HHIN) limits the Network to providing information about the releases of radioactive materials from 1944 to 1972. This publication provides a brief historical sketch and describes Hanford's releases into the air, water and soil. The last section discusses the uncertainties in the estimates of the amount of radioactive material released and whether the government continues to withhold important information.

Historical Background

In 1943, the U.S. government chose a location in southeastern Washington state for the Hanford Nuclear Reservation, now known as the Hanford Site. The federal government condemned privately-held property and moved the residents so it could build plants to make plutonium. Because of the wartime secrecy, few people knew why Hanford was built. It was not until August 6, 1945, when the United States dropped an atomic bomb on Hiroshima, Japan, that area residents and most Hanford workers learned that Hanford made plutonium. 1 Hanford had begun making plutonium in September 1944, when the B reactor began operating. Hanford plutonium was used in the first atomic explosion in July 1945 at Alamogordo, New Mexico, and in the bomb that was dropped on Nagasaki, Japan (August 9, 1945).

For more than 40 years, Hanford released radioactive materials into the environment. Although Hanford's mission of making plutonium became public knowledge in 1945, most of the public and some Hanford workers did not know about these releases until 1986. In February 1986, the U.S. Department of Energy, in response to public pressure and a request under the Freedom of Information Act, released 19,000 pages of documents, some dating back to World War II. These documents revealed that releases of radioactive materials from Hanford had contaminated the air, the Columbia River, and the soil and groundwater.

Citizen activists played an important role in making these and other Hanford documents open to the public. In the early 1980s, many citizen groups began to scrutinize the operation of Hanford. One group, the Hanford Education Action League (HEAL), raised numerous questions about the past and present safety of Hanford. HEAL, along with other groups, such as Physicians for Social Responsibility (PSR) and Hanford downwinders, pressed the U.S. Department of Energy for the release of additional historical documents. Journalists, as well as state and Native American governments, also played important roles in the release of Hanford records.

The information in these documents eventually led to the Hanford Environmental Dose Reconstruction Project (HEDR) which began in late 1987. HEDR made estimates of the radiation doses the public may have received from Hanford. The project was beset with public controversy from the start. Citizens leveled charges of conflicts of interest at the U.S. Department of Energy (which owned Hanford and was funding the study), as well as at Battelle Pacific Northwest Laboratory, a longtime Hanford contractor, which was conducting the scientific work. To try to alleviate some of the public's concern, an independent technical steering panel was created to direct the project. 2

In 1992, HEDR funding was transferred from the Department of Energy to the Centers for Disease Control and Prevention (CDC). In 1994, Battelle's HEDR contract expired and CDC hired other contractors to complete the study. The HEDR study is scheduled to complete its work in 1998.

A key step in reconstructing doses is estimating how much radioactive material was released to the environment. Scientists refer to the amount released as the source term. By reviewing Hanford's historical documents, HEDR obtained information for making release estimates. The following sections describe these source term estimates for the air, the Columbia River, and the soil and groundwater.

Air Releases

Most of Hanford's air releases came from the routine operation of the chemical plants used to separate plutonium and uranium from used reactor fuel. Some of the air releases came from the nuclear reactors along the Columbia River. 3 The major radioactive releases occurred between 1944 and 1957. The largest ones were during 1945, when there were no filters on the stacks of the separations plants. In only five months, Hanford discharged more than half of the entire amount of iodine-131 released during the entire 1944-1972 period. 4 Radioactive materials in the form of gases and particles went up the stacks.

Filters were installed in 1948 that greatly reduced, but did not eliminate, the releases to the air. More advanced filters were installed in December 1950 that further reduced the releases. However, the filters would occasionally fail and this would result in some above-normal releases. The largest of these filter failures occurred in the spring and summer of 1951. 5

In all, Hanford released over 200 radionuclides. 6 Reconstructing past doses from Hanford's releases was a huge undertaking. (By the time HEDR is complete in 1998, it will have cost about $30 million.) To help set priorities, HEDR scientists used scoping studies.

Green Run Most of Hanford's radioactive releases happened as part of routine operations. But Hanford's largest single release of iodine-131 was the result of a secret military experiment. "Green Run" refers to a secret U.S. Air Force Experiment at Hanford that released somewhere between 7,000 and 12,000 curies of iodine-131 to the air on December 2-3, 1949. The experiment was called the Green Run because it involved a processing "run" of uranium fuel that had been cooled for only a short time (16 days), and was, therefore, "green." The normal practice in 1949 was to cool the fuel 90 to 100 days before processing. The longer cooling time allows for radiation, especially iodine-131, to decay to lower levels. The reported purpose of the Green Run was to test monitoring equipment the Air Force was developing for its intelligence activities concerning the Soviet Union's nuclear weapons program. The Green Run remained a top government secret until the 1980s when reports were made public in response to Freedom of Information Act requests. The requests were filed by the Hanford Education Action League and the Spokesman-Review newspaper, both based in Spokane. The U.S. Air Force continues to withhold significant information about the Green Run including the names of the official(s) who ordered the experiment and the intelligence unit that participated in the monitoring.

Some radionuclides, while not posing a significant risk to the public, might have been a special hazard to workers, security guards and soldiers at Hanford. This situation is part of continuing HEDR work and a report is expected in 1998.

HEDR estimated the amounts of iodine-131 and other radioactive materials Hanford released into the air between 1944 and 1972. Table I (below) presents the radionuclides for which specific estimates were made. The release estimates are in curies, a unit of measurement of radioactivity. As an example, HEDR estimated that Hanford released about 740,000 curies of iodine-131 from 1944 to 1972. For comparison purposes, the Three Mile Island nuclear power plant accident in 1979 released an estimated 15 to 24 curies of iodine-131, and the Chernobyl accident released an estimated 35 million to 49 million curies of iodine-131 in 1986. Table I also presents the half-life (a measurement of the rate of radioactive decay) of each radionuclide.