Friday, December 14, 2012

Japan's Nuclear Regulatory Authority: Higashidori Nuke Plant in Aomori May Have Active Faults, Restart Doubtful

While the nation is engrossed with the upcoming Lower House election on December 16, the much-maligned Nuclear Regulatory Authority goes out and does one field survey after another at the nuclear power plant sites. It has just declared the fractured zones underneath the reactor at Tsuruga Nuclear Power Plant as "active faults", indicating it won't even conduct the safety inspection for the restart.

Now, after spending two days in Higashidori Nuclear Power Plant in Aomori, the same group of researchers headed by Dr. Shimazaki, deputy chairman of NRA says it is likely that the faults that run through the plant compound are active faults that moved as recently as less than 100,000 years ago. Just like in the case of Tsuruga Nuke Plant, all 5 experts agreed.

Go go, Nuclear Regulatory Authority's geologists and seismologists, before LDP shuts you down.

From Kahoku Shinpo (12/15/2012):

東通「活断層の可能性」再稼働困難になる恐れ 規制委調査

NRA's investigation on Higashidori "Active faults possible", restart may be difficult


On December 14, the field survey team of the Nuclear Regulatory Authority concluded the two-day investigation of the faults in the compound of Higashidori Nuke Plant operated by Tohoku Electric Power Company (Higashidori-mura, Aomori Prefecture). The team leader Dr. Kunihiko Shimazaki, NRA's deputy chairman, said that some of the faults "may have been active as recent as less than 100,000 years ago." All five members of the team pointed out to the possibility of active faults.


The results will be discussed in the meeting in Tokyo on December 20. Tohoku Electric may be forced to review its seismic assessment of the nuclear reactors, and the restart of the plant may become difficult.


For the two faults, "F-3" and "F-9" that run north-south on the west side of the reactors, the survey team went in the trench to closely examine the geological features around the faults. The researchers also studied the documents that Tohoku Electric had submitted, including the application for permission to install nuclear reactor.


According to the seismic design standard set by the national government, an active fault inside the compound that is newer than 120,000 to 130,000 years ago has to be considered. Deputy Chairman Shimazaki raised the possibility that "F-3" and "F-9" faults moved more recently than 100,000 years ago, and said "If we consider that possibility, it explains the change in strata such as small faults nearby like "s-14" and "s-19".


Deputy Chairman Shimazaki said of the December 20 meeting, "Basically, the point of discussion will be whether we can say these "are not active faults" or not."


Vice President of Tohoku Electric Takeo Umeda said, "Scholars may have their own opinions, but we have ours and we will talk about them in the December 20 meeting." He emphasized again the company's view that there is no active fault that would necessitate the review of seismic design.

Thanks to Dr. Shimazaki, I now fully understand the position of Tohoku Electric, or any nuclear power plant operator. Tohoku Electric does not see any active fault because that's not what they are looking for. They are looking for confirmation that there is no active fault, and as long as there is no such confirmation they can keep looking. To keep on looking is as good as no fault.

This is what Dr. Shimazaki said in the press conference on December 10 when he announced the active faults in Tsuruga Nuke Plant:

After all, the plant operator is in a very delicate position, particularly those who actually do the investigation may be placed in a very delicate position, I suspect. Basically, [the operator] continues the investigation in order to prove that it is not an active fault, and as long as it cannot prove that it has to continue the investigation, so to speak. That is a totally different position than ours.

Aomori Prefecture is conservative. I don't know about long time ago, but ever since the nuclear facilities have started to be built in the prefecture - Rokkasho Reprocessing Plant, Higashidori Nuke Plant, Ooma Nuke Plant - the prefecture heavily depends on government special subsidies and special taxes it can assess these nuclear operators. The plant operators also give generous "gifts" to the municipalities where the plants are located. It will vote LDP in the coming election, according to press reports, maybe in all 4 districts.


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