The center, part of Moscow's non-proliferation initiative to create a network of enrichment centers under the UN nuclear watchdog's supervision, will be based at a chemicals plant in Angarsk, Siberia. The center will also be responsible for the disposal of nuclear waste.
"This is an important document that will create conditions for Armenia to join the nuclear non-proliferation regime," Russian nuclear chief, Sergei Kiriyenko, told reporters after talks between Russia and Armenia's prime ministers, Viktor Zubkov and Serzh Sarkisyan, respectively.
Uranium enrichment is planned to begin in Angarsk in 2013. Kazakhstan joined the initiative in 2006, when the Central Asian state, which holds 15% of the world's uranium reserves, signed an agreement with Russia to set up their first enrichment joint venture.
Ukraine said earlier it could also join the project. Russia previously said it would grant any country the use of the future center, proposed by President Vladimir Putin to defuse tension over Iran's controversial nuclear program.
Kiriyenko also said the two countries would establish a joint venture to prospect and produce uranium in Armenia, whose uranium deposits are estimated at up to 60,000 metric tons.
"Armenia and Russia will each hold 50% in the joint venture," he said, adding that Russia would invest $3 million in additional prospecting in the ex-Soviet state.
Kiriyenko said Russia would bid in a tender for the construction of a 1,000-MWt power unit on the site of the 1976 nuclear power plant, which he said could start in 2010-2011. He stated that Russia had a good chance of winning the tender, estimated as being worth $1 billion.
Armenia has been under pressure from the EU to close its sole nuclear power plant, which generates 40-50% of its electricity, due to possible environmental threats.
In September 2003, the plant came under the five-year trust management of INTER RAO UES, a subsidiary of Russia's state NPP operator Rosenergoatom and UES electricity monopoly.
Kiriyenko was formally dismissed on Monday as head of the Federal Nuclear Power Agency to focus on his other job as chief of the Rosatom state corporation, set to take on the agency's functions and step up the construction of nuclear power plants at home and abroad.