Russia 's nuclear power plants are dangerously under-prepared for earthquakes and other disasters, said a state review conducted after Japan 's Fukushima disaster and obtained by AFP Thursday.

The unusually candid report was presented to a council chaired by President Dmitry Medvedev on June 9 and obtained by the Oslo-based environmental NGO Bellona Foundation, which released a copy to AFP.

Russia has until now steadfastly defended its 10 nuclear power plants and 32 reactors against criticism and Prime Minister Vladimir Putin on April 30 pronounced the country's nuclear safety system "the best in the world."

But the State Council review revealed 32 glaring weaknesses including reduced seismic impact safety standards and a lack of a clear strategy for securing spent nuclear fuel and other radioactive waste at many plants.

"The strength (stability) of engineering structures of most nuclear power plants does not meet current regulatory document requirements for stresses that occur from extreme natural impacts," the report said.

"Spent nuclear fuel storage facilities near reactors ... are in a critical condition" at the Beloyarsk nuclear power plant in Ural Mountains region of Sverdlovsk , it added.

The Beloyarsk plant was the second constructed by the Soviet Union and first went on line in 1964.

The report was released to senior government officials and a select group of Russian non-governmental organisations but not publicised in the Russian media.

Rosatom state nuclear agency chief Sergei Kiriyenko mentioned the report in passing over the weekend and said the various recommended changes would cost around five billion rubles ($180 million).

Environmentalists said the report for the first time acknowledged problems whose Soviet-era shortcomings have been criticised by watchdogs and Russian neighbours such as Norway for many years.

"We knew everything" in the report, Bellona's Russian nuclear programme director Igor Kudrik told AFP.

"But this is honest information from Rosatom itself that there are problems, and we are kind of surprised that they admitted it publicly in such a dramatic manner," he added.

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