Chubu Electric Power Co. plans to request a safety inspection of the No. 4 reactor at the Hamaoka power plant in Shizuoka Prefecture as soon as possible so it can restart the idled unit.
The application will be sent to the Nuclear Regulation Authority by the end of March, the utility said Wednesday.
The Hamaoka plant, Chubu Electric's sole nuclear power plant, was shut down at the request of the government over safety concerns after the 2011 Fukushima disaster. It stands on the assumed epicenter of a massive earthquake predicted by scientists.
The Nagoya-based utility announced Wednesday it will spend around ¥70 billion on construction work and other measures to improve the ability of reactors 3 and 4 to withstand earthquakes in order to meet new nuclear regulations introduced in July.
The utility also said it will brief local governments on the application for the inspection to win their consent before submitting it to the NRA.
Given the additional safety measures, construction improvements on the No. 3 unit are expected to take until the end of September 2016, a year and a half later than planned, while the work for the No. 4 unit will likely finish at the end of September 2015, about six months later than the previous plan, Chubu Electric said.
The company has yet to say when it will apply for an inspection of reactor 3 because it is putting all priority on the application for the No. 4 unit.
All of Japan's reactors are currently shut down.