The Japan Atomic Energy Agency will start investigating a geologic fault running under its nuclear facility in Tsuruga, Fukui Prefecture, that hosts the nation's only prototype fast-breeder reactor.
The agency said it will commence boring Tuesday to determine the activity, size and direction of two of the nine fault fracture zones around the Monju fast-breeder reactor. It plans to compile the results by March.
The announcement Friday is in line with instructions issued in August by the Nuclear and Industrial Safety Agency, which has been replaced as the atomic energy industry's watchdog by the recently founded Nuclear Regulation Authority.
The atomic energy agency said one of the targeted sites is a lineament south of the complex that could possibly be a fault, and will check whether it extends toward the reactor.
The agency will also check the relation between an active fault just 500 meters west of the reactor and the fracture zones beneath the complex by studying the landscape and subterranean structure, including underwater, via electrical current surveys and boring.