Nuclear safety advisers slam stress tests

February 01, 2012

By SOPHIE KNIGHT / Staff Writer

Two advisers to Japan’s nuclear safety agency have slammed stress tests being conducted on idle nuclear reactors, saying they do not guarantee the safety of the facilities and calling into question the impartiality of the U.N. nuclear agency, which approved Japan’s handling of the tests on Jan. 31.

Masashi Goto, a former nuclear power plant designer, and Hiromitsu Ino, emeritus professor at the University of Tokyo, who both served as members of an advisory committee to Japan's Nuclear and Industrial Safety Agency (NISA) for the stress tests, said the International Atomic Energy Agency (IAEA) had sent a delegation to merely rubberstamp the process.

At a news conference in Tokyo on Jan. 27, both Goto and Ino criticized the narrow scope of the test criteria and the lack of citizen involvement.

“The calculations are all based on ideal scenarios: ‘If this piece of equipment breaks, then will another kick in?’” said Ino. “It doesn’t look at complex scenarios, such as system-wide failure due to the aging of the plant, or human error."

The stress test model, which was imported from Europe, assesses the extent to which nuclear power plants can physically withstand “site-specific natural disasters”—namely, earthquakes and tsunami—and whether they have sufficient safety procedures in place to avoid power loss.

The Japanese government announced last July that all the nation's nuclear plants would undergo the tests following the meltdown at the Fukushima No. 1 nuclear power plant caused by the magnitude-9.0 Great East Japan Earthquake earlier that year.

All but three of Japan’s 54 reactors are now offline, and must pass the stress tests as well as gain the approval of both local and national governments before they can be put back online.

The tests do not assess aging of plant equipment or other potential causes of accidents, such as fires, plane crashes, tornadoes or lightning.

According to Goto, even the scenarios for the two disasters the tests purport to simulate are insufficient.

“The tsunami was not just an issue of water; there was rubble and boats flowing in, large amounts of fuel, fires out at sea—none of those factors were considered. Is it sufficient that a plant can withstand an earthquake 1.8 times stronger than that it was designed for? What happens if an earthquake twice as strong hits?” he said, referring to the magnitude used in a stress test simulation at the Oi nuclear power plant in Oi, Fukui Prefecture.

Ino described the stress tests as an “optimistic desk simulation” in a written critique distributed at the conference. He argued that the tests will only be meaningful if they replicate the conditions at the Fukushima plant when the accident occurred.

Although high radiation levels inside the plant are still impeding investigations into damage caused by the earthquake rather than the giant tsunami it spawned, Ino said water gauge readings taken from the pressure vessel suggests that the quake ruptured pipes, and that this should be reflected in the stress test criteria.

Ino also voiced doubts about the impartiality of the IAEA, citing the organization's previous assessment of the Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture, following the 2007 Chuetsu-Oki earthquake, when the agency said the damage was less than expected without having any knowledge of the condition of the reactor pressure vessel or pipes.

“It is highly unlikely that the IAEA can undertake a fair assessment. The agency promotes the nuclear industry and it is only investigating the stress tests for a short time,” he said. “The last IAEA report was very flimsy, and I fear it’ll be the same this time."

James Lyons, the head of the IAEA delegation that left Japan on Jan. 31, emphasized that the IAEA’s mission was to refine the review of the stress tests, not to change the criteria of the tests.

“What we saw was a process that we felt comfortable with,” he said at a news conference on the same day. “We were looking to provide suggestions on how they could improve the process but that doesn’t call into question the adequacy of the original process.”

The IAEA released a preliminary report approving Japan’s implementation of the stress tests, saying they were “generally consistent” with the agency’s own safety standards, as well as issuing recommendations and suggestions for the secondary assessment to be undertaken by the NISA.

One of the recommendations was to improve communication with residents living in the immediate vicinity of the plant, and to allow them to attend discussion sessions about the result of the stress tests.

In his critique, Ino described a meeting of the advisory committee on Jan. 18 in which citizens were shut out and forced to watch the proceedings via a monitor from another room.

“It is inadmissible that the citizens’ right to closely observe the review process was inhibited, the minimum requirements of democracy for such a crucial decision-making on whether or not to reopen nuclear power plants after a historic nuclear disaster,” he wrote.

According to Goto, residents would be hard to please even if they were more involved in the process.

“In reality what would make nuclear power really safe would be to make entire plants earthquake-proof, everything down to the wiring system,” he said. “That’s the viewpoint of the residents, and if you can’t do it for financial reasons then I think they wouldn’t want nuclear power at all.”

An IAEA spokesman, Greg Webb, said that the agency's mission is to improve safety regulations among member countries. However, he stressed that the IAEA cannot guarantee the safety of any nuclear power plant and does not have the power to shut plants or keep them open.

“Nuclear safety is a national responsibility in any country. No country has asked the IAEA to be a safety watchdog. We don’t conduct nuclear safety inspections,” he said at the news conference.

By SOPHIE KNIGHT / Staff Writer
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Masashi Goto, left, and Hiromitsu Ino at a news conference in Tokyo on Jan. 27 (The Asahi Shimbun)

Masashi Goto, left, and Hiromitsu Ino at a news conference in Tokyo on Jan. 27 (The Asahi Shimbun)

  • Masashi Goto, left, and Hiromitsu Ino at a news conference in Tokyo on Jan. 27 (The Asahi Shimbun)

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