Oi reactors pass stress test, safety panel says


Staff Writer

The Nuclear Safety Commission approved on Friday the results of the first-stage stress test for two reactors at the Oi power plant in Fukui Prefecture, clearing another key condition for bringing them back online.

The brief approval meeting sparked outrage among the nuclear foes present.

The Friday approval is the first from the safety commission, a government nuclear advisory body, for the stress tests now being conducted by the Nuclear and Industrial Safety Agency, the country’s main nuclear regulatory body under the Ministry of Economy, Trade and Industry.

Prime Minister Yoshihiko Noda and three relevant ministers will soon begin the process of judging whether to authorize the restart of the Oi plant’s reactors 3 and 4, shut down in light of the meltdown crisis at the Fukushima No. 1 plant.

The central government has said the consent of local governments will be needed to restart any reactors, though this is not a legal requirement.

Only two of Japan’s 54 reactors are currently operating. The rest have been suspended for regular inspections, and utilities can’t restart them until their safety is confirmed through the stress tests and approval from political leaders.

The tests, based on computer simulations, are supposed to check the ability of reactors to withstand huge earthquakes and tsunami beyond those assumed under the initial design conditions.

The first stage examines the possibility of accidents that would lead to damage in a reactor’s core, and the second stage will gauge how nuclear materials would be released to the outside environment. The second stage is not necessarily a condition for a utility to restart a reactor, according to the government.

Kansai Electric Power Co., which runs the Oi plant, submitted test results saying the two reactors could withstand an earthquake 1.8 times more powerful than required under the government safety guidelines and tsunami up to 11.4 meters high.

NISA reviewed Kepco’s stress test report and approved it in February, saying the utility has taken sufficient measures to prevent the reactors from facing a situation similar to the Fukushima accident, such as a total power loss that could develop into meltdowns of fuel rods.

The safety commission has been reviewing whether NISA’s judgement was appropriate through discussions with external experts and officials from NISA and the utility.

The commission’s decision Friday to approve the test results angered nuclear opponents who were observing the extraordinary meeting, which lasted for only about five minutes.During the brief meeting, some observers shouted “Stop this meeting!” and “This is a crime!”

As commission Chairman Haruki Madarame closed the meeting and quickly left the room, some people climbed over tables placed between the commission members and observers and demanded that officials bring the chairman back.

Afterward they emphasized that the safety commission’s approval was unacceptable and expressed their dismay that the meeting did not have any discussion.

They said the causes of the Fukushima crisis have not been fully investigated, and some of the experts who participated in the stress test have not approved the results.

They also pointed out that Madarame himself said the first-stage stress test is not enough to ensure safety. The nuclear opponents said clearance of the second stage should be made a prerequisite for restarting reactors.

Madarame has already expressed his intension to resign as commission chairman.

“How can a person who is leaving soon be responsible for restarting the Oi reactors?” one of the opponents asked.