The Tokyo Electric Power Co. (Tepco) has sought for help from nuclear power authorities in France to help them contain the crisis at the Fukushima power plant in quake-hit Japan.
TEPCO has asked for support from concerns including the Electricite de France (EDF), Areva and the Nuclear Energy Agency, according to French industry and energy minister Eric Besson.
On 28 March, water contaminated with radiation 100,000 times over normal was found in concrete tunnels extending beyond one reactor.
According to Japanese Prime Minister Naoto Kan, the situation at the nuclear power station requires high levels of vigilance.
Earlier, EDF had also announced a set of relief measures including sending experts and robots to the Fukushima plant following radiation leaks at the plant.