WASHINGTON - The Clinton administration will announce today a two-track plan to get rid of 50 tons of highly radioactive surplus plutonium from the nation's dwindling stockpile of nuclear weapons.
Some of the toxic material will be "immobilized" - encased in glass or ceramic blocks and consigned to a permanent underground repository. The rest will be combined with conventional nuclear power plant fuel and used in commercial plants under the plan, which was made available to The Washington Post.
The Savannah River Site hopes the Energy Department will build a $500 million plant to convert plutonium into fuel for commercial power reactors. SRS may be asked to turn some of the plutonium into glass at the Defense Waste Processing Facility.
The Post didn't indicate where the repository or conversion work will be located.
Both disposition methods in the $2 billion program involve immense technical, economic and political uncertainties. But the Energy Department, after a three-year study, concurred with the National Academy of Sciences that they are preferable to all 34 other known methods of plutonium disposal. In reaching the decision, the administration followed the process prescribed by law for actions that have a major environmental impact.
Scientists recommended pursuing more than one option because, according to the NAS report, "it is crucial that at least one of these options succeed .°.°. and because the costs of pursuing both in parallel are modest in relation to the security stakes."
In selecting two methods, the Energy Department discarded such options as launching the plutonium into space or sinking it in the ocean. The department also rejected as too dangerous the "do-nothing" alternative, keeping the plutonium in secure storage.
Keeping the material in storage would be easiest and cheapest, officials said, but that would perpetuate the danger of the material falling into the hands of terrorists or rogue nations. It also could make Russia suspect that the United States plans to retrieve the plutonium some day for use in new weapons.
Publication of the Energy Department's "preferred alternatives" for disposing of the plutonium marks a milestone in the history of nuclear weapons. Material produced in secret over four decades at a cost of untold billions of dollars for the purpose of destroying the Soviet Union will now itself be destroyed - in a public process, in cooperation with Russia and under international supervision.
Plutonium, the basic building block of nuclear weapons, is extracted by a chemical process from uranium fuel irradiated in a nuclear reactor. It is highly toxic, radioactive and flammable in some forms.
The United States produced about 98 tons of it before ending production in the late 1980s. As little as 15 pounds can be fashioned, relatively easily, into a crude nuclear explosive device, according to scientists.
U.S. defense strategy assumes that this nation will maintain a reduced nuclear arsenal indefinitely. But with the size of that arsenal shrinking rapidly, the government had to decide what to do with the surplus plutonium.
The decision either to destroy it by using it as nuclear fuel or to immobilize it in glass or ceramics ends a debate over whether the material is an asset or a liability. Given the cost of producing it, some people - especially in Russia - wanted to reuse it for its energy content.
Others, including many senior officials of the Clinton administration and arms-control activists, wanted it destroyed by any method that did not involve using it as fuel. But the administration finally concluded that some fuel use is necessary.
Alerted that the administration was contemplating some use of plutonium as mixed-oxide - MOX - fuel in power plants, some arms-control activists already have begun to campaign against it. They argue it will open the door to routine commercial use of plutonium in the United States and in other countries.
Much of the material assembled by the administration for today's announcement is designed to address that argument. While some plutonium "may ultimately be burned in existing reactors, every possible means will be pursued to ensure that federal support for this unique disposition mission does not encourage other civil uses" of plutonium or the extraction of plutonium for reuse from conventional spent fuel at power plants, a summary of the plan states.
The administration is planning to release a Tuesday letter to President Clinton from a panel of prominent nuclear scientists who say it is "essential to pursue both" forms of disposition - conversion to MOX and vitrification - because vitrification alone will not satisfy Russia, however appealing it may be to the anti-MOX arms-control community.
"In fact," the letter says, "there is much reason to think that the Russians will not eliminate their plutonium stockpile at all if the United States implements only immobilization." The Russians "might then merely store their stockpile of weapons plutonium indefinitely, which is what we should most wish to avoid."
According to a senior Energy Department official, the United States and Russia agreed recently to put their plutonium storage and disposition programs under supervision of the International Atomic Energy Agency. He and other officials stressed that every aspect of the plutonium disposition program was designed with an eye toward assuring Russia that the United States really is out of the plutonium business and encouraging the Russians to follow a similar course.