Judgment of temporary disposal at Ikata Nuclear Power Station: January 17, 19:03
With a decision on the 17th, the Hiroshima High Court questioned the actions of the Nuclear Regulatory Commission and Shikoku Electric Power regarding safety against earthquakes and volcanic eruptions.
Regarding the earthquake at the provisional disposal, the focus was on the effects of an earthquake occurring on an active fault near Ikata Nuclear Power Plant.
Shikoku Electric Power has confirmed that the "Chuo Tectonic Line Fault Zone" extending from Shikoku to Kinki is 8 km away from the Ikata Nuclear Power Station, and that there is no serious impact because measures are taken even if an earthquake occurs. Claimed to be.
However, the court ruled that the boundary of the stratum very close to the Ikata site could not be denied to be an active fault.
The site of the nuclear power plant is within 2 km, and Shikoku Electric Power has conducted a thorough investigation, even in the case where the epicenter is very close to the site, which is strictly evaluated by the new regulatory standards of the country. He pointed out that there were errors and omissions in the process by which the NRA judged that there was no problem.
Regarding the eruption of the volcano, he questioned the new regulatory standards of the country itself, which were used in the screening for restarting the nuclear power plant.
According to the national regulatory standards, safety against volcanic eruptions is evaluated from two main points of view: whether the location of the nuclear power plant is an appropriate place where pyroclastic flow does not reach, and whether cinders and volcanic ash affect the operation of the nuclear power plant Is supposed to.
Judgment on the “location of nuclear power” will evaluate the impact of a volcanic eruption within a range of 160 km.
The Court concluded that the regulation could be interpreted as premised on anticipating and preparing for the eruption time and scale of the subject volcano, and concluded the views of several volcano experts. He pointed out, "At the current level of science and technology, it is difficult to accurately predict the timing and scale of an eruption, and regulatory standards are unreasonable."
On the other hand, he pointed out that it should be decided based on social wisdom about how much danger is allowed when determining whether the location of a nuclear power plant is appropriate.
Regarding the catastrophic eruption of Mt. It has been fairly tolerated. "
However, regarding the effect of the eruption, the amount of volcanic ash when an eruption similar to a catastrophic eruption occurred at Mt. Aso was underestimated, and Shikoku Electric Power's response and the Nuclear Regulatory Commission recognized that Concluded that his decision was irrational.
A judicial ruling that had previously ruled out nuclear power operation was concerned with either earthquake or volcano safety, but the decision cast doubts on both.