Radiation levels at the Onagawa nuclear power plant in Miyagi prefecture are about 700 times higher than normal but are still low, the Tohoku Electric Power Company has said, according to the Maichi Shinbum website. Japan's Nuclear and Industrial Safety Agency dismissed the possibility that the Onagawa plant was to blame, saying it was likely caused by the radioactive substances that scattered when a hydrogen explosion hit the troubled Fukushima plant on Saturday.