Tsuruga nuke plant active fault faces study

JIJI

Japan Atomic Power Co. has submitted plans to a government agency to conduct additional research on an active fault and similar areas between tectonic plates that lie under its Tsuruga nuclear plant in Fukui Prefecture.

The research, including the digging of soil near the Urazoko fault, comes as the Nuclear and Industrial Safety Agency last month pointed to potential crush zones, made up of coarse rock fragments, moving together with the fault and instructed the firm to conduct in-depth studies.

Some of the crush zones run directly under the reactor buildings at the Tsuruga plant.

The additional research plan, submitted Monday to the agency’s panel of experts, was basically approved.

Masaru Kobayashi, head of the agency’s department for evaluating the safety and quake-resistance of nuclear plants, said that “on-site inspections will be carried out if necessary.”

An official of Japan Atomic Power said the purpose of the additional ground research is to restore the public’s trust in the safety of the Tsuruga plant, noting the company has not changed its view that there is no possibility of the crush zones moving together with the Urazoko fault.

NISA said last month the Urazoko fault may have moved some 20,000 to 30,000 years ago and thus can be considered active. Under government guidelines, nuclear plants cannot be built on an active fault.