The Nuclear Regulation Authority called on a panel of experts to re-evaluate its earlier findings that the No. 2 reactor at the Tsuruga nuclear plant is active. NRA Commissioner Kunihiko Shimazaki said that this came about when plant operator Japan Atomic Power Co. submitted new data supporting their claims that the geologic fault where No. 2 reactor is situated remains inactive.
The NRA assessed in May that the Fault D-1 directly under the No. 2 reactor is active based on the results of a large-scale trench excavation, which would render the reactor useless. A fault in the trench, “K” which moved in the last 120,000 – 130,000 years is said to be linked to Fault D-1 and under Japan law, utility companies are not allowed to construct facilities directly above fault lines that have moved within the last 120,000 – 130,000 years.
Japan Atomic Power maintained that D-1 is inactive, based on the data they gathered where they cited the age of a very small amount of volcanic ash found in the layer among other information. Shimazaki and other panel members will visit the Tsuruga power plant in Fukui Prefecture to check on the land sometime in January. He said that, “we have to check whether the data (presented by Japan Atomic Power) will affect our judgment. We would respond carefully, but in a swift manner.” A meeting will be held to discuss preparations needed prior to the on-site visit.