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LOOKING BACK: The Destructive Legacy of Plutonium Reprocessing
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James P. Thomas

On February 27, 1986, the Department of Energy released a six-foot-high stack of documents, 19,000 pages in all, concerning the Hanford plutonium plant in south-central Washington State. Most of the documents had been classified as secret or otherwise not available to the public. The shocking contents of those documents helped launch an unprecedented wave of scrutiny of America’s nuclear weapons complex.

Within three years, safety concerns forced the closure of nearly every major U.S. nuclear weapons manufacturing plant. Over the past 20 years, pressure from citizens, tribes, and state officials has forced the government to provide far more information about Hanford’s lethal legacy, although some important details remain classified.

The 1986 collection encompassed 40 years of environmental monitoring reports on plutonium manufacturing at the Hanford Nuclear Site. Originally part of the Manhattan Project, Hanford contributed nearly two-thirds of America’s weapons-grade plutonium. It was built and operated under government contract by corporations such as DuPont (1943-1946) and General Electric (1946-1964).

Before the 1986 revelations, the public and even many workers knew few details about what Hanford had done during its 40-year history of producing plutonium for the U.S. nuclear weapons arsenal. What those six feet of documents revealed was disturbing: Hanford’s routine plutonium operations had inundated parts of four states— Idaho, Oregon, Montana, and Washington—with large amounts of radioactive materials. Some had even seeped over the border and into Canada. Hanford’s plutonium factory discharged hundreds of thousands of curies[1] of radioactive iodine-131 into the air and millions of curies of various radionuclides into the Columbia River, some of which reached the Pacific Ocean. Nearly all of Hanford’s environmental releases occurred between 1944 and 1964.

Most surprising of all, the huge releases were not the result of accidents, but rather the consequence of routine operations. Although Hanford officials were aware of the danger posed to nearby residents, they were far more concerned with preserving secrecy and increasing plutonium production. Hanford scientists even avoided collecting samples of the contamination so as not to raise any public concern. No wonder it took more than four decades for those exposed to learn of Hanford’s menace.

Because the two wartime reprocessing plants initially had no stack filters, Hanford spewed nearly all of its total iodine-131 atmospheric releases during the first three years (1944-1947). Prevailing winds blew the iodine-131 onto pastures throughout eastern Washington, northeastern Oregon, and the Idaho panhandle. Cows and goats grazed on the contaminated pasture grass, concentrating the radioactive contamination in their milk. People unwittingly drank the contaminated milk, especially young children, whose rapidly developing thyroids received the largest doses. Stable iodine is a nutrient required for the proper development and functioning of the thyroid gland, but those people whose thyroids are exposed to radiation during childhood are at higher risk for developing thyroid cancer later in life. The earlier in life a person is exposed, the higher the risk. Even though Hanford managers knew as early as the first year of operations about the milk contamination, they decided against notifying the public.

Hanford’s plutonium-production reactors pumped more than 100 million curies into the Columbia River. DuPont built three reactors during World War II, and General Electric added five larger ones as the Cold War escalated. All eight had once-through cooling. This process pumped river water directly through the reactor core, where trace amounts of minerals became activated in the intense radiation field.

Following a short time in hold-up basins to allow for some radioactive decay and thermal cooling, the still-contaminated water poured back into the Columbia River. Hanford engineers initially designed the basins to retain the cooling water from four to six hours before its return to the river. Yet, as the reactor’s operating levels dramatically increased in the late 1950s to produce plutonium for the escalating U.S. nuclear arsenal, the retention time dropped to as little as 15 minutes. The result was a dramatic increase in the amount of radioactive contamination present in drinking water for nearby towns and in aquatic life and animals dependent on the river. By chance, scientists discovered significant contamination in oysters along the Pacific coasts of Washington and Oregon. The effluents from Hanford’s plutonium-production reactors made the Columbia River the most radioactively polluted waterway outside of the Soviet Union.

People who had lived in the area during the years of highest releases (1945-1964) wanted to know whether their health problems were caused by radiation from Hanford. In response to these concerns, the federal government launched two scientific studies about the Hanford releases and their impact. The first was the Hanford Environmental Dose Reconstruction (HEDR) project. Its purpose was to estimate the amount of ionizing radiation released from Hanford, to determine which areas were contaminated, and to calculate the dose levels of radiation that individuals sustained.

The second was an epidemiology study that assessed whether those exposed as children to Hanford’s atmospheric releases of iodine-131 were at a higher risk for thyroid cancer than those without similar exposures. Funded by the Centers for Disease Control and Prevention (CDC), scientists at the Fred Hutchinson Cancer Research Center in Seattle conducted the Hanford Thyroid Disease Study (HTDS).

In 1987 the Energy Department directed the Pacific Northwest National Laboratory (PNNL) to carry out the HEDR project. This choice was controversial as Battelle, which operated PNNL, was a longtime contractor at Hanford. Because of concerns about a conflict of interest, the Energy Department created a Technical Steering Panel to guide the study in 1988 and transferred funding to the CDC in 1992. The final reports were issued in 1994.

Because Hanford’s environmental monitoring program had not collected enough samples throughout its 40 years of operations to support a dose reconstruction effort, Battelle had to develop computer models to estimate the amounts of radiation released from the plants, how those releases were transported through the environment, and what foods were consumed by people in the exposure area and in what amounts. HEDR’s work established that as many as two million people had been exposed to potentially harmful amounts of radiation.

The second study examined more than 3,000 people who had been exposed as young children during 1945-1947, the years of highest release of iodine-131. The HTDS final report was released in 2002. Study scientists concluded that the exposures to iodine-131 had not raised the number of thyroid cancers in the study population more than what would otherwise have been expected. Other scientists have criticized the study’s statistical analysis because it failed to properly account for the large uncertainty in the thyroid dose estimates. The critics posit that if the full range of dose uncertainty were incorporated into the analysis, the results would be consistent with previous epidemiology studies. The combined cost of HTDS and HEDR was approximately $53 million.

Shortly after HEDR released a preliminary set of dose estimates in 1990, lawyers representing thousands of former residents filed suit against the contractors who had operated Hanford for the federal government. The first trials were held in 2005 with mixed results. Of the six cases that went to the jury, the plaintiffs won two, and the defendant contractors won four. Each side has appealed the verdicts. To date, the litigation has cost the federal government more than $70 million, as it indemnified the contractors and agreed to pay all of their legal costs.

In addition to the huge amount of radiation transported off the Hanford site, the plutonium manufacturing operations created a vast inventory of wastes. More than 400 billion gallons of radioactive and toxic chemical wastes were discharged to the soil, contaminating more than 200 square miles of groundwater. Years beyond their design life, 177 underground storage tanks hold approximately 50 million gallons of high-level wastes. More than one-third of these tanks have leaked. Mammoth quantities of solid wastes have been buried in unlined disposal trenches. When one considers the numerous leaks from transfer pipes at the site as well as the contamination of the reactors and process buildings, it is not difficult to imagine why some observers have labeled Hanford a national sacrifice zone.

Although cleanup of Hanford originally was estimated to cost $50 billion and to take until 2018 to complete, recent estimates put costs at more than $60 billion and completion at 2035 at the earliest. Yet, the Energy Department has already spent more than $31 billion on the project. With more than 30 years left, the total expenditures could approach $100 billion.

Hanford is not alone. The Energy Department also is cleaning up reprocessing wastes in South Carolina and Idaho. A commercial attempt at reprocessing spent fuel operated for six years in West Valley, New York, but the plant became so contaminated that it became inoperable. The federal government took over the cleanup 24 years ago, but even with this massive effort, much of the job remains to be done.

Despite the lessons of Hanford and these other locations, the Bush administration continues to press Congress to fund the development of a new “responsive infrastructure” to provide the United States with the capability to produce additional nuclear weapons. As the U.S. experience with manufacturing materials for nuclear weapons attests, producing nuclear weapons is costly, not only in dollars but in environmental and health consequences. These costs need to be weighed against strategic objectives.

If the United States continues to maintain nuclear weapons as part of its national security establishment, then it needs to ensure that the development of those weapons does not put its citizens at risk. All manufacturing facilities should be scrutinized to ensure they are in compliance with established environmental, safety, and health standards. Countries should also learn from the U.S. production woes and think twice before constructing any new sites.


James P. Thomas is a Seattle-based consultant in historical research and policy development. He has been involved in Hanford plutonium plant issues since 1984 as a citizen activist, research director of the Hanford Health Information Network, and a paralegal.


1. A curie is a unit of measure for radioactivity. By way of comparison, the accident at Three Mile Island released an estimated 15-24 curies of iodine-131.

Posted: November 1, 2006