Russia has begun to build the world’s first floating nuclear power plant despite warnings from environmentalists that it risks creating a disaster.

The £100 million vessel, the Lomonosov, is the first of seven plants that Moscow says will bring vital energy resources to remote Russian regions as well as potential foreign markets. It will house two 35-megawatt reactors capable of supplying a city of 200,000 people when it starts operations, in three years’ time.

Environmental groups and nuclear experts fear that floating plants will be more vulnerable to accidents and terrorism than land-based stations. They point to a history of naval and nuclear accidents in Russia and the former Soviet Union, most notoriously at Chernobyl in 1986.

Nils Boehmer, an expert on Russia’s nuclear industry at Bellona, a Norwegian environmental group, said that floating power plants “raised a lot of new questions because this kind of facility has never been used in the world before”.

“There is so little infrastructure in these remote areas that it will be very difficult to control the plants if something goes wrong. It will also be difficult to maintain a full cohort of engineers,” he told The Times.

“There will be a risk of hijack and terrorist attack because it is much harder to secure floating facilities. The security services in Russia have done exercises on nuclear-powered ice-breakers and found that it is very easy to take control of them.”

Sergei Kiriyenko, head of the Russian atomic energy agency, insisted that the project was safe and pointed to the disaster on board the Kursk nuclear submarine in 2000 as evidence.

The Kursk sank in the Barents Sea in 2000 with the loss of all 118 crew after a torpedo exploded on board. The floating power plants will house reactors similar to those used in the Russian submarine fleet. “The most reliable test of such a reactor was the Kursk tragedy. After the boat was raised, specialists proved that the reactor could be put into service at that very moment,” Mr Kiriyenko said.

The Sevmash plant, which will produce the floating power plants, is the largest shipbuilding complex in Russia, employing more than 25,000 people. Most of its contracts have been for nuclear submarines.

The first vessel will be towed to a bay off the northern White Sea port of Severodvinsk in 2010 to supply electricity to nearby defence facilities. The far-eastern regions of Kamchatka and Chukotka, which are governed by Roman Abramovich, the owner of Chelsea Football Club, are in line for other vessels.

The atomic energy agency said that at least 12 countries were also interested in buying floating nuclear plants. China, Indonesia, Malaysia, Algeria and Argentina have all been mentioned as potential buyers.

Vladimir Kuznetsov, a former head of the Russian nuclear inspectorate, co-authored a report on floating nuclear plants that concluded that they were “inherently unsafe”. He told The Times yesterday that there was a danger of enriched uranium, the essential component of a nuclear bomb, ending up in the wrong hands.

“There is a clear danger of nuclear proliferation if these plants are sold to other countries. There is also a very high risk of terrorist attack,” he said.

The floating plants are backed by President Putin as part of a programme to raise the proportion of Russian electricity generation from nuclear power from 17 per cent to 25 per cent. They can operate for up to 15 years without refuelling and have an expected working life of 40 years before being towed back to the production yard for decommissioning.

The United States toyed briefly with building floating nuclear plants along its eastern seaboard in the 1970s. The Westinghouse Electric Company even built a huge dry-dock in Jacksonville, Florida, to produce and launch the units.

But energy conservation measures after the 1973 oil shock made the project less attractive economically, and the accident at Three Mile Island in 1979 turned the public mood against nuclear power.

Russia has revived the idea as a solution to the problems of energy supply in its sparsely populated regions. The floating unit generates a small fraction of the power of a standard Russian land-based nuclear power plant. Russian authorities argue that their long experience of operating nuclearpowered ships shows that the technology is safe.

Once towed into position off the coast, the vessel will be linked to the onshore grid to supply heat and light to the local population.

Experts say that it can also operate as a desalination plant, producing up to 240,000 cubic metres of fresh water a day from the sea.

The Sevmash plant is expected to sell 20 per cent of its electricity to private consumers in the energy-hungry east of Russia, which often experiences power shortages in winter, when temperatures regularly plunge to minus 40C.

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