However, the Japanese government warned that it would take decades to dismantle completely.

The cold shutdown condition is a key milestone in efforts to bring the plant under control, according to the BBC. It means that the water being used to cool nuclear fuel rods remains below boiling point, ensuring that the fuel cannot reheat.

The Fukushima nuclear power plant was in near-meltdown following Japan’s earthquake and tsunami in March. Explosions at four of the plant’s nuclear reactors knocked out vital cooling systems. Workers at the plant used sea water in an attempt to cool the reactors, but this reportedly caused a build-up of waste water and allowed contaminated liquid to be released into the sea.

Tokyo Electric Power Company, which operates the plant, said that the cold shutdown condition also means that the release of radioactive materials is under control and that levels of public radiation exposure have been reduced.

Prime Minister Yoshihiko Noda said: “Even if unforeseeable incidents happen, the situation is such that radiation levels on the boundary of the plant can now be maintained at a low level.”

More than 80,000 people were displaced by the problems at the power plant, having been forced to leave their homes in the area. Radiation in some places still remains too high for them to return.

Earlier this week, the government said that it could take 40 years to decommission the plant and clear up the surrounding areas.