Russia's state nuclear energy corporation was expected to switch off a nuclear reactor Sunday in a closed city in Siberia.
The reactor has been producing weapons-grade plutonium for four decades, a senior U.S. nonproliferation official said Saturday.
The reactor, ADE-4, is one of two in the city of Seversk that have been extraneous remnants of the Soviet Union's nuclear weapons program since the Cold War. For 15 years, they produced plutonium that the Kremlin neither needed nor wanted.
Opened in secret in the 1960s to feed the arms race, the reactors have continued to operate because of their peculiar construction as defense-industry suppliers.
The Defense Ministry stopped purchasing plutonium in 1993, rendering the reactors obsolete for their primary purpose. But the reactors could not be closed, and plutonium was still produced, because the reactors were also a primary source of heat and power to the bitterly cold regions along the Tomsk River, where no equivalent utility sources had been built.
Russian energy officials said switching off the weapons-material reactors, which are powered by uranium and produce plutonium as a byproduct, would have meant cutting off a large fraction of the utilities for the cities of Seversk and Tomsk. The cities have a combined population of about 600,000.
"That is obviously critical when you are facing temperatures of 40 below," said William Tobey, deputy administrator of the National Nuclear Security Administration, a semiautonomous agency in the U.S. Department of Energy that coordinates nonproliferation programs.
Under a cooperative program between the Russians and the Americans, the United States has provided $285 million to underwrite the refurbishment of a coal plant to provide an alternate utility service to the region, Tobey said.
The plant has been refurbished enough to switch off the first reactor this week. It is expected to be completed and in full service by June, allowing the second reactor, ADE-5, to be turned off as well.
Although an agreement on the program was reached in 1997 and work on the coal plant began in 2005, Russia notified the United States of its plans to turn off the reactor only Friday, two U.S. officials said. It had been expected to close later this year.
Officials at Rosatom, the Russian state nuclear energy corporation, could not be reached for comment Saturday.
Tobey declined to say how much plutonium the reactors had produced, saying that Russia had opposed the public release of data related to its nuclear programs.
(KATHIMERINI, 04/21/2008)