A chemical procedure used to make peanut butter will be used in Russia to reprocess rocket fuel from nuclear missiles being taken out of service.


The U.S. company Thiokol and its Russian partner Askond on Wednesday announced that they have reached a deal to process 30,000 tons of a substance known as unsymmetrical dimethyl hydrazine, or UMDH. It is known as heptyl in Russian.


The substance is highly toxic, highly unstable and extremely harmful to humans and the environment. But the START I Treaty, signed in 1991 and implemented last December, stipulates that the fuel be drained from nuclear rockets put out to pasture. That means getting rid of enough fuel to thrust 1,000 Russian missiles toward the United States.


Disposing of the liquid propellant, however, is as dangerous as the fuel itself, and presents enormous hazards.


"What to do with the fuel has posed a major technological issue and a major technological challenge," said Michael Mobbs, a Moscow-based attorney representing Thiokol. Both sides also worked under intense time pressure, because Russia's ability to warehouse UMDH for prolonged periods is hamstrung by the age of its storage facilities.


Russia rejected an initial proposal by the United States to incinerate the fuel. No one has ever dealt with such large quantities of UMDH before, and the risks of burning 30,000 tons of fuel seemed too great.


Instead, the U.S. Defense Nuclear Agency, a division of the Department of Defense, solicited bids from U.S. companies that had the technology to dispose of the UMDH without triggering a health or ecological disaster. Thiokol won the bid with a proposal to convert the rocket fuel into common commercial chemicals.


The process is called catalytic hydrogenation, and according to Mobbs, is a safe, closed process that emits no hazardous by products.


"There is hardly a chemical refinery in the world that does not use catalytic hydrogenation," he said. "It can be used to make peanut butter."


The Moscow office of Greenpeace acknowledged that heptyl is a highly dangerous substance, but a spokesman said he was unaware of plans to reprocess the fuel in Russia.


Thiokol will develop, test and assemble factories in the United States for export to Russia. Three Russian cities that already have facilities using UMDH will handle the reprocessing. One of them is the Moscow suburb of Sergiev Posad, formerly known as Zagorsk.


The first plant should be delivered at the beginning of next year.


The end products of the process are ammonia and dimethyl amine, a substance used in making detergents.


Russia will be able to sell those chemicals on the market and keep the profit.


The reprocessing plants will also remain as commercial enterprises.


The project's $25 to $30 million price tag is being paid for by the Nunn-Lugar Program, named for the two U.S. senators who sponsored a disarmament program called Cooperative Threat Reduction.


Thiokol is the company that produced the rocket engines blamed for the 1986 explosion that killed the crew aboard the U.S. space shuttle Challenger. Mobbs said much has changed since then.


"That was an old management team," he said. "That was a good many years ago."


Thiokol is joined in the venture by two American companies and the Russian company Askond.


According to a statement released by the State Committee for Defense Industries, which participated in the government-to-government negotiations, Askond is a company authorized by the Russian Federation for missile conversion.


"The management and senior staff of Askond include some of the most accomplished specialists in Russia in the engineering, testing, production and conversion of ballistic missile systems," the statement read.