Russia's controversial floating nuclear power plant has headed out for its first sea voyage.

The floating plant, the Akademik Lomonosov, was towed Saturday out of the St. Petersburg shipyard where it was constructed. It is to be towed through the Baltic Sea and around the northern tip of Norway to Murmansk, where its reactors are to be loaded with nuclear fuel.

The Lomonosov is to be put into service in 2019 in the Arctic off the coast of Chukotka in the far east, providing power for a port town and for oil rigs.

The project has been widely criticized by environmentalists. Greenpeace has dubbed it a "floating Chernobyl."