Safety measures being introduced at the Onagawa nuclear power station in Miyagi Prefecture, northern Japan, including a sea wall designed to prevent flooding from tsunamis, will not be completed until sometime in fiscal year 2020, which will begin on 1 April, press reports said.At the end of last month owner and operator Tohoku Electric received permission from Japan’s Nuclear Regulation Authority to restart Unit 2 at the Onagawa station subject to a public consultation period.But before a possible restart can be considered, safety upgrades introduced following the March 2011 Fukushima-Daiichi accident need to be completed.