Earthquake caused ‘no significant damage’ to Japanese nuclear plant – IAEA

The impact of an earthquake last year on the Kashiwazaki Kariwa nuclear power plant in Japan caused no major harm to safety equipment, the United Nations International Atomic Energy Agency (IAEA) said today.

The seven-unit plant, the world's biggest, shut down safely during the earthquake and remains shut down. A very small radioactive release at the time of the earthquake was below public health and environmental limits, the IAEA said.

Phillipe Jamet, who led a team that recently viewed key internal components in the plant, said they found "no significant damage to the integrity of the plant."

The IAEA team's site visit followed three days of discussions with Japanese regulatory officials, the plant's operators, and other experts that the Agency called "open and constructive."

The team recommended an international cooperative effort which could expand ongoing Japanese studies and make a contribution to the evolution of international safety standards.

The 16 July 2007 earthquake significantly exceeded the level of seismic activity for which the Kashiwazaki Kariwa plant, in the coastal prefecture of Niigata, north west of Tokyo, was designed.

The Director General of the IAEA, Mohamed ElBaradei, said today that an international response to the earthquake is appropriate because of its relevance to other nuclear plants worldwide. He welcomed Japan's continued cooperation with the effort.

The earthquake also caused fractures on the surface of the site. Before the reactors at the Tokyo Electric Power Company (TEPCO) owned plant started up, between 1985 and 1997, it was acknowledged that geological faults ran deep beneath the site but were considered stable, the team said.

Geologists are investigating if surface fractures caused by the earthquake correspond to deeper faults. The team observed one fault during its site visit and was able to conclude that it was stable. Confirmation of the stability of others is underway, the IAEA said.