The amount of plutonium buried at the Hanford Nuclear Reservation in Washington State is nearly three times what the federal government previously reported, a new analysis indicates, suggesting that a cleanup to protect future generations will be far more challenging than planners had assumed.
Plutonium waste is much more prevalent around nuclear weapons sites nationwide than the Energy Department’s (DOE) official accounting indicates, but the problem is most severe at Hanford, a 560-square-mile tract in south-central Washington that was taken over by the federal government as part of the Manhattan Project
The plutonium does not pose a major radiation hazard now, largely because it is, according to DOE, under “institutional controls” like guards, weapons and gates. But because it takes 24,000 years to lose half its radioactivity, it is certain to last longer than the controls and the gates.
The fear is that in a few hundred years, the plutonium could reach an underground area called the saturated zone, where water flows, and from there enter the Columbia River. Because the area is now arid, contaminants move extremely slowly, but over the millennia the climate is expected to change, experts say.
The finding on the extent of plutonium waste signals that the cleanup, still in its early stages, will be more complex, perhaps requiring technologies that do not yet exist. But more than 20 years after the Energy Department vowed to embark on a cleanup, it still has not “characterized,” or determined the exact nature of, the contaminated soil.
In 1996, the department released an official inventory of plutonium production and disposal. But Mr. Alvarez analyzed later Energy Department reports and concluded that there was substantially more plutonium in waste tanks and in the environment. The biggest issue is the amount of plutonium that has leaked from the tanks, was intentionally dumped in the dirt or was pumped into the ground.
Gerry Pollet, executive director of the environmental group Heart of America Northwest, said the government should embrace a cleanup plan that assures that even thousands of years into the future, an unsuspecting public will not be overexposed. “What is reasonably foreseeable is that there are people who will be drinking the water in the ground at Hanford at some point in the next few hundred years,” Mr. Pollet said. “We’re going to be killing people, pure and simple.”
The new analysis indicates that the chemical plutonium separation process was not nearly as efficient as the government claimed and that a lot of the plutonium was left behind in various stages. It also suggests that estimates of plutonium production by the Energy Department and its predecessors, including the Atomic Energy Commission and the Manhattan Project, were not nearly as accurate as scientists and bureaucrats said they were.
A preliminary estimate based on waste characterization data indicates that from 1944 to 2009 about 12.7 metric tons of plutonium was discarded at U.S. nuclear weapon production facilities. This is more than three times than the U.S. Department of Energy’s (DOE) last official estimate of waste losses (3.4 tons) made in 1996. Of the 12.7 tons, about:
- 2.7 tons in high-level radioactive wastes are stored as liquids in tanks and as granulated material in bins on the sites of former U.S. military reprocessing plants;
- 7.9 tons are in solid waste, which DOE plans to dispose at the Waste Isolation Pilot Project (WIPP) a geological repository in New Mexico for transuranic wastes. About half is already emplaced; and
- 2.1 tons are in solid and liquid wastes buried in soil prior to 1970 or held up in facilities at several DOE sites. The DOE considers most of this plutonium to be permanently disposed.
Sources: Plutonium Wastes from the U.S. Nuclear Weapons Complex by Robert Alvarez, Senior Scholar, Institute for Policy Studies, Washington, D.C. July 7, 2010; available at: http://djcoregon.com/wp-files/pdfs/alvarez-plutonium-wastes-07-12-10.pdf / New York Times, 11 July 2010
Contact: Heart of America Northwest