The stress tests to review nuclear plant safety don’t include lessons from the Fukushima No. 1 disaster, effectively ignoring the reason for running the checks, according to two government advisers.
The stress tests were initiated after the earthquake and tsunami wrecked the Fukushima plant last March, causing radiation leaks in the worst nuclear disaster since Chernobyl in 1986.
Yet the checks ignore the potential for two natural disasters to occur at the same time, which is what happened at Fukushima, said Masashi Goto, a former atomic plant designer who is a member of the Nuclear and Industrial Safety Agency’s stress test advisory committee. The tests also don’t take into account the ages of plants, he said.
“The safety review system used before the Fukushima accident was wrong,” said Hiromitsu Ino, a professor emeritus at the University of Tokyo, who also serves on the committee. “The same system is being used for the current stress tests without taking into consideration the causes of the Fukushima accident.”
The stress tests are computer-simulated disaster scenarios and don’t include a review of potential human error and multiple equipment failure, Goto told reporters last week.
Tokyo Electric Power Co.’s 40- year-old Fukushima No. 1 power station was hit by three explosions and reactor core meltdowns after the quake and tsunami damaged power supplies, disabling cooling systems.
Test results have been submitted to the government for 14 of Japan’s 54 reactors, even though a committee charged by the state to detail the causes of the Fukushima disaster will publish its report only in July.
NISA has approved the results for the first round of stress tests on two reactors at Kansai Electric Power Co.’s Oi nuclear station in Fukui Prefecture. Kepco will need approval from local citizens and the central government before it can restart the reactors.
“Stress tests should be undertaken on Fukushima No. 1 before the accident to see if they can actually correctly simulate what happened,” Ino said at the briefing in Tokyo with Goto. “It’s completely wrong for NISA to approve stress tests before getting an answer to those kind of questions.”
Tepco partly agreed with the recommendation made by Ino and Goto’s advisory committee by saying it will run a stress test to simulate tsunami hitting the Fukushima No. 1 plant, according to Ino.
Still, the utility doesn’t plan to run a simulation test for an earthquake or a combination, and Tepco’s tsunami calculation doesn’t consider reactor damage from debris or explosions of leaked fuel, all of which occurred on March 11, Goto said.
NISA has no plans to change the way the reviews are being conducted, Tatsuya Taguchi, a NISA official in charge of nuclear safety regulatory standards, said Jan. 27. The concerns of Ino and Goto have been discussed, Taguchi said.
“We are doing the best we can to reflect reality,” Taguchi said.
Mitsubishi Heavy Industries Ltd., a maker of nuclear plant equipment, runs the disaster simulations for the utilities, which pass the results to NISA, Ino and Goto said.
The reports are reviewed by the Japan Nuclear Energy Safety Organization, which employs former MHI staff, raising a potential conflict of interest, they said.
Some members of the advisory committee receive research funding from Mitsubishi Heavy and related firms, Ino and Goto said. Representatives of communities hosting reactors haven’t been included in the safety review, they said.
MHI spokesman Hideo Ikuno said Jan. 27 the firm isn’t in a position to comment.