The Nuclear and Industrial Safety Agency has concluded five nuclear power plants have no active faults below their building sites.
NISA, the nuclear watchdog of the Economy, Trade and Industry Ministry, is looking into whether active faults exist below the sites of nuclear power plants nationwide. In a hearing of four experts held on Friday, the conclusion was reached that the five plants in question had no active faults below them, it said.
The five plants are: Kyushu Electric Power Co.'s Sendai plant in Kagoshima Prefecture and Genkai plant in Saga Prefecture; Shikoku Electric Power Co.'s Ikata plant in Ehime Prefecture; Japan Atomic Power Co.'s Tokai No. 2 plant in Ibaraki Prefecture; and Tohoku Electric Power Co.'s Onagawa plant in Miyagi Prefecture.
The experts examined whether faults below each plant's buildings could be subject to the following scenarios:
-- Cause quakes just below nuclear reactors.
-- Be pulled by active faults near the compounds and cause ground movement.
-- Cause ground movement from an earthquake that occurs in a distant place.
Based on past excavation survey results and other data, the experts concluded the five plants' sites are not susceptible to any of the three possible scenarios.
Meanwhile, NISA requested additional research to draw conclusions on Kansai Electric Power Co.'s Mihama and Takahama plants and Japan Atomic Energy Agency's Monju fast-breeder reactor, all in Fukui Prefecture, as it deemed the Mihama plant and Monju may fall into the second category and the Takahama plant into the third.
NISA has deemed Chubu Electric Power Co.'s Hamaoka plant in Shizuoka Prefecture and Chugoku Electric Power Co.'s Shimane plant in Shimane Prefecture fall into the third category.