Onagawa Nuclear Power Plant Unit 2 Restart Announced Postponement for several months Tohoku Electric Power Company. Tohaku Electric Power Co. has increased the amount of safety measures currently being carried out regarding the restart of Onagawa nuclear Power Station Unit 5 in Miyagi Prefecture. The restart of Unit 5, which was scheduled for around May, will be delayed by several months due to the increase in the amounts of security measures being taken. The timing of the restart was postponed from February to May in September last year, citing fire control work.