IAEA double-checks Japanese tests

24 January 2012

A team of experts from the International Atomic Energy Agency has kicked off its review of Japanese nuclear safety tests with a series of open meetings in Japan.

James Lyons addresses the first open meeting of the IAEA expert mission to Japan (Image: G Webb/IAEA)

The ten-strong IAEA International Complementary Safety Assessment Review Mission is in Japan to review the methodology of the stress tests carried out at Kansai's Ohi nuclear power plant.

Two-phase stress tests were mandated by the Japanese government following the March 2011 Fukushima Daiichi nuclear power plant accident. Utilities are required to examine the safety margin of important pieces of equipment in accordance with guidelines set by the country's Nuclear and Industrial Safety Agency (NISA) and Nuclear Safety Commission (NSC). Based on the results of these initial tests, carried out while units are shut down for inspections, the government is to decide whether a reactor can or cannot resume operation.

Ohi unit 3 was the first Japanese nuclear power plant to complete the first step of the mandatory stress tests in October 2011, but in common with all Japanese power plants that have entered an outage since the Fukushima accident no permit has yet been issued for the plant to restart.

As more Japanese reactors reach their scheduled outage dates, an increasing number of plants have been forced to remain offline: on 13 January, when Shikoku Electric Power Co shut down Ikata 2 for refuelling and a mandatory periodic inspection, only five of Japan's 54 reactors were left in operation. The figure is set to drop even further as Tepco's Kashiwazaki Kariwa unit 5 and Chugoku's Shimane 2 also shut down in the next few days

James Lyons, director of the IAEA's Nuclear Installation Safety Division, is leading the team. "Our mission really is to look at the approach and methodology that NISA is using. We want to see how Japan is evaluating safety at its nuclear power plants," he said, adding that the review would contribute to improved nuclear safety both in Japan and worldwide.

The IAEA mission, arranged at the request of the Japanese government, is to spend nine days in Japan during which it will hold meetings with Japanese officials and conduct a site visit to the Ohi plant in Fukui Prefecture, before delivering a preliminary report to Japanese officials on 31 January.

Researched and written
by World Nuclear News