Russia shut down a reactor capable of producing weapons-grade plutonium on Thursday - the last of its kind in the world - days after the country participated in a historic US nuclear security summit, the Ria Novosti news agency reported. Russian President Dmitry Medvedev had announced the imminent shutdown of the reactor, which has been operational in the Siberian city of Zheleznogorsk since 1964, at the summit.
Plutonium can be used in nuclear weapons, among other things, DPA reported.
Moscow had abandoned the production of weapons-grade plutonium in 1995. Since then, the Zheleznogorsk reactor had only produced electricity and heat. A power station being built with US help will eventually take over that task.
Two other reactors capable of producing weapons-grade plutonium had previously been shut down in 1992.
Russian Foreign Minister Sergei Lavrov and US Secretary of State Hillary Rodham Clinton signed a pact in Washington on Tuesday that paves the way for each country to destroy 34 metric tonnes of weapons-grade plutonium starting in 2018.
Sergei Kiriyenko, head of the state nuclear energy corporation Rosatom, estimates that the pact will cost Russia 2.5 billion to 3 billion dollars. The US has pledged to provide Russia with 400 million dollars for Moscow's effort.
The amount of plutonium to be destroyed would be sufficient to build 17,000 nuclear weapons, Kiriyenko said.