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Credibility of nuclear safety regulation


December 22, 2012


EDITORIAL: Nuclear safety watchdog’s quake risk assessments deserve respect





The Nuclear Regulation Authority has said that the Higashidori nuclear power plant operated by Tohoku Electric Power Co. in Aomori Prefecture sits on faults that are probably active.

The assessment was supported by all members of the NRA expert panel, according to the nuclear safety watchdog.

We cannot help but wonder why experts who examined the same faults before the construction of the nuclear power plant and later didn’t realize this.

The panel’s opinion came as a fresh reminder that the government’s past inspections of plans to build new nuclear power plants were disturbingly slipshod. The actual safety assessments were left totally to the electric utilities planning to build the facilities.

Before examining the faults running under the Higashidori plant, the NRA also checked the faults underneath two other nuclear power plants--Kansai Electric Power Co.’s Oi plant in Fukui Prefecture and Japan Atomic Power Co.’s Tsuruga plant, also in Fukui Prefecture.

The assessments have all delivered a heavy blow to claims by the electric power companies that the plants are safe.

Some executives within the power industry are complaining that the NRA’s commissioners and experts involved in the fault checks are dominated by people in the anti-nuclear camp.

But the experts commissioned to assess the faults are independent researchers selected from a list of candidates recommended by the Japanese Society for Active Fault Studies and other organizations after their relations with utilities were checked for a possible conflict of interest.

The panel’s field surveys and assessment meetings were open to the public, and final judgments were made through a transparent process. Both the government and the private sector should heed the panel’s conclusions seriously.

The utility and the governor of the prefecture where the plant is located have questioned the “scientific grounds” on which the assessment was made. Behind their criticisms are concerns that the safety warning could put the utility in serious financial trouble and have a huge negative impact on the local economy.

These are certainly important concerns that should be dealt with, but they don’t provide justification for modifying the safety assessment by the scientists.

If scientists allow concerns about economic interests to affect their safety assessments in any way, the credibility of nuclear safety regulation will be destroyed.

This is a lesson that must never be lost in light of the earthquake and tsunami disaster last year that triggered meltdowns at the Fukushima No. 1 nuclear power plant.

If electric utilities and local communities challenge the credibility of the expert assessments concerning faults, the NRA should call on them to prove their arguments in public.

Basically, which side has a stronger case should be determined through exhaustive and purely scientific debate.

The problem is that the appointments of the members of the watchdog have yet to be approved by the Diet due to political conflict and the Lower House election held earlier this month.

Some politicians of the victorious Liberal Democratic Party are arguing that the NRA’s commissioners should be selected anew now that the party has returned to power. They say the choices of the members of the body were made by the Democratic Party of Japan before the party fell from power and have not yet been formally approved.

But the NRA’s commissioners should not be replaced according to the political motives of a party.

It was the LDP itself that demanded that the NRA be a highly independent agency based on Article 3 of the national government organization law. Unreasonable political intervention in the NRA must not be allowed.

To be sure, the NRA has shown some signs that it still has a lot to learn about the way it carries out its job. It has, for instance, made repeated revisions to its forecasts concerning the spread of radioactive materials in case of severe nuclear accidents. But the blunders have not been sufficiently serious to demand that the commissioners be replaced.

The ruling and opposition parties should work together to make sure that the appointments of the NRA commissioners will be swiftly approved by the Diet during the next session.

There are many safety assessments the body needs to make.



December 22, 2012
Editorial: NRA should re-examine faults, crustal structure below Aomori nuclear plants




An expert team under the government's Nuclear Regulation Authority (NRA) has concluded that a fault that runs below the premises of Higashidori Nuclear Power Plant on the Shimokita Peninsula in Aomori Prefecture is active. This is the second time that the NRA has recognized that a fault below a nuclear plant is active -- following the Tsuruga Nuclear Power Plant in Fukui Prefecture -- even though its operator denies that.

The move has demonstrated that the electric power companies that operated the plants did not sufficiently examine the crustal structures around these facilities, and that the government's nuclear power regulator had failed to detect the faults. The move has also raised questions about safety inspections on other nuclear plants.

Tohoku Electric Power Co., the operator of the Higashidori power station, has claimed that the fault below the premises of the facility was created when strata containing clay was swelled by underground water, and was not active. The utility did not take the fault into account in its quake-resistance assessment of the plant.

However, all five members of the expert team have concluded that the fault is active. The members were selected from among experts who had never previously been involved in safety assessments of nuclear plants and who were recommended by academic societies including the Japanese Society for Active Fault Studies. Therefore, the assessment can be lauded as neutral. Past safety assessments, conducted by experts selected mainly by the ministries and agencies concerned, had been criticized as being lenient toward power suppliers.

The NRA is considering methods of judging whether faults around nuclear plants are active in line with new nuclear safety standards, which is necessary because it is extremely difficult to precisely predict local vibrations and the shear of the ground caused by a temblor. It is essential to ascertain the scale and other details of the active fault and reassess how far the plant can withstand a quake in accordance with the new standards. However, such measures alone are far from sufficient.

The active fault that the expert team confirmed also stretches onto the premises of a neighboring nuclear plant that Tokyo Electric Power Co. is building. Furthermore, nuclear power-related facilities are concentrated on the Shimokita Peninsula, including a spent nuclear fuel reprocessing plant and the Oma Nuclear Power Plant. An 84-kilometer-long fault also runs from north to south off the east coast of the peninsula.

Although the operators of nuclear facilities on the peninsula have denied the fault is active, some experts have asserted it is an active fault and pointed to the possibility that it could move in tandem with other faults including those beneath nuclear plants in the area.

Now that the past safety assessment of the Higashidori plant has been called into question, the NRA should re-examine all faults and the crustal structure of the Shimokita Peninsula as a whole. Some of the members of the expert team have called for detailed studies of the fault. The NRA should review the system in which safety assessments has been left to the discretion of nuclear plant operators, and play a leading role in re-examining the fault.

What is of great importance is to ensure the independence and transparency of the NRA. To that end, the appointments of top officials of the NRA need to be approved by the Diet.

Three months have passed since the NRA was set up by reorganizing the government's nuclear regulating bodies. Still, procedures for gaining approval of appointments of the body's top officials from the Diet have been postponed under the Democratic Party of Japan (DPJ)-led administration. The new administration to be inaugurated by the end of this year should promptly refer the appointments to the Diet for approval.


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