Former NRA boss calls for review of safety screening method — The Japan Times

” Japan needs to review its current method for screening nuclear plant safety, seismologist and former senior regulator Kunihiko Shimazaki said in a recent interview.

The current method risks underestimating the magnitude of possible earthquakes that may hit nuclear plants, Shimazaki, former acting chairman of the Nuclear Regulation Authority, said.

He said a review was needed on the method to calculate the design basis earthquake, or the maximum quake motion that can occur around a nuclear plant, which is currently part of the NRA’s screening procedures.

Shimazaki said that he confirmed the need for such a review after examining data on powerful quakes that hit Kumamoto Prefecture and other areas in Kyushu in April.

“The NRA has to be aware that the current screening procedures have shortcomings,” he said, adding it is “very dangerous to keep using the method.”

Before leaving the NRA in September 2014, Shimazaki was in charge of assessing quake and tsunami impacts as part of its nuclear safety screening process.

The current method risks underestimating design basis earthquakes when it is applied to vertical faults found mainly in western Japan, he said.

The design basis earthquakes for Kansai Electric Power Co.’s Takahama and Oi nuclear plants, both in Fukui Prefecture, and Kyushu Electric Power Co.’s Genkai nuclear plant in Saga Prefecture, should be recalculated based on a different method, he said.

The NRA should draw up a revised method by taking into account new data, including on strong tremors such as the Kumamoto quakes, Shimazaki said.

The No. 3 and No. 4 reactors at the Takahama plant have passed the NRA’s safety screening. The NRA is expected to approve Kansai Electric’s request for extending operational periods at the plant’s No. 1 and No. 2 reactors beyond 40 years, a basic lifetime for nuclear reactors in Japan. ”

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*Editorial: 40-year rule for nuclear reactors on verge of being a dead letter — The Asahi Shimbun

” The 40-year lifespan for nuclear reactors, established after the catastrophic accident at the Fukushima No. 1 nuclear power plant in 2011, is now in danger of being watered down to irrelevance.

The rule requires the decommissioning of aging reactors, starting with the oldest, for a gradual, carefully controlled process of phasing out nuclear power generation in this country.

The Nuclear Regulation Authority (NRA) on April 20 formally decided that the No. 1 and No. 2 reactors at Kansai Electric Power Co.’s Takahama nuclear power plant in Fukui Prefecture, which have been in service for over 40 years, meet new nuclear safety standards introduced after the devastating 2011 accident.

This is the first license renewal for a reactor that has been in operation for more than four decades under the new standards.

If they pass the remaining regulatory inspections concerning technical details by the July deadline, the reactors will likely continue to generate electricity for two more decades.

The 40-year lifespan provision was introduced through a revision to the law after the Fukushima disaster.

Just one service life extension of up to 20 years is allowed, but only as an “extremely exceptional” measure.

This exception was made to avoid a shortage of electricity. But concerns about any serious power crunch have virtually dissipated thanks to a marked rise in levels of power and energy conservation in society.

The NRA’s formal decision to extend the life of the two aging reactors came amid a series of earthquakes rocking central Kyushu around Kumamoto Prefecture which have been described by the Japan Meteorological Agency as “a deviation from the rules extracted from past experiences.”

Many Japanese are concerned that the quakes could affect Kyushu Electric Power’s Sendai nuclear plant in neighboring Kagoshima Prefecture. The NRA’s decision to grant an exception to the rule so quickly could have the effect of relaxing the safety standards and deepening public distrust of the government’s nuclear regulation.

The Abe administration is leaving all licensing decisions on individual reactors entirely to the NRA. But it has mapped out a long-term energy supply plan based on the assumption that the service life of reactors will be extended.

Prime Minister Shinzo Abe, who repeatedly pledged to lower Japan’s dependence on nuclear power as much as possible, has been changing his stance little by little without announcing any clear policy shift.

The NRA’s mission is to enhance the safety of nuclear plants from a scientific viewpoint.

But the way the nuclear watchdog assessed the safety of the reactors at the Takahama plant has raised questions about its appropriateness. The NRA has, for instance, allowed Kansai Electric Power to delay required quake resistance tests.

If it has scheduled its assessment work in a way to ensure that the July deadline will be met, the agency has got its priorities completely wrong.

A troubling situation is now emerging where decisions on whether to decommission specific reactors are effectively left to the utilities that operate them. As a result, these decisions are being based primarily on whether extending the life of the reactors will pay.

Operating many nuclear reactors in Japan, a small country with a large population that is highly prone to earthquakes and other natural disasters, inevitably entails a large risk.

This grim reality was the starting point for the reform of the nuclear power policy prompted by the Fukushima accident.

If the government sticks to the policy of maintaining nuclear power generation, the burden on society, including the costs of disposing of nuclear waste, could increase over the long term.

There is a clear global trend toward raising energy self-sufficiency through efforts to develop renewable energy sources.

A transition period may be necessary. But the only policy that makes sense is to shut down reactors steadily over a period of years.

The 40-year rule is one of the key principles of this policy. The government should remember this fact.

–The Asahi Shimbun, April 21 ”

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City to investigate NRA’s conclusion that radioactive rice unrelated to Fukushima plant work — The Asahi Shimbun

” MINAMI-SOMA, Fukushima Prefecture–Addressing cover-up suspicions, the city assembly here will investigate how the Nuclear Regulation Authority concluded that work at the crippled Fukushima nuclear plant was not the cause of radioactive contamination of rice paddies.

The assembly unanimously decided to investigate during a regular session that started on Dec. 2 in response to a petition submitted by a citizens group called “Genpatsu-jiko no Kanzen-baisho o Saseru Minami-Soma no Kai” (Minami-Soma’s group that requires complete compensation for the nuclear accident).

The group doubts the NRA’s assertion that the contamination of rice harvested in the city in 2013 was not related to debris-removal work at the Fukushima No. 1 nuclear plant. It has also expressed outrage that the government has stopped trying to confirm the cause.

“The government should continue a scientific investigation so that farmers can be engaged in rice farming without anxieties, and accurate information can be conveyed to citizens in evacuation,” the petition said.

“Suspicions remain that the NRA concealed facts with the intention of reaching that conclusion.”

The agriculture ministry had raised the possibility that work to remove debris at the Fukushima plant in 2013 scattered radioactive substances that contaminated rice paddies in Minami-Soma more than 20 kilometers away.

However, the NRA reached a different conclusion, saying that while radioactive substances were stirred up by the work, they remained within the nuclear plant compound, south of Minami-Soma.

The NRA did not specify the likely source of the contamination, and the government discontinued the investigation.

The citizens group’s petition, submitted to a regular assembly session in September, asked the city to scrutinize the process in which the NRA reached its conclusion and to gather views from several scholars.

The NRA’s public relations office declined to comment on the issue on Dec. 8.

“As the documents of the petition were not issued to the NRA, we cannot make a comment,” the office told The Asahi Shimbun.

As for the issue of determining the cause of the contamination, NRA Chairman Shunichi Tanaka has said that it is a job for the agriculture ministry.

“I absolutely cannot accept (Tanaka’s remark),” Minami-Soma Mayor Katsunobu Sakurai said. ”

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