In this file photo dated July 30, 2012, the Onagawa nuclear power plant is seen in Onagawa, Miyagi prefecture, northern Japan. (PHOTO / AP)

TOKYO — Japan's Tohoku Electric Power said on Monday it plans to restart reactor No 2 at its Onagawa nuclear station around September after additional safety construction works delayed the process.

Tohoku's Onawaga plant was closest among Japan's nuclear stations to the epicentre of the magnitude-9 quake in March 2011.

The company said it was working to secure materials, equipment and workers for the safety construction works and was now aiming to restart the reactor around September

The company received a de facto regulatory approval to restart the No 2 reactor in 2020, by gaining a modification approval, but has seen a delay in the completion of safety constructions.

READ MORE: Tohoku Electric gets nod to restart reactor damaged in 2011 disaster

On Monday, the company said it was working to secure materials, equipment and workers for the safety construction works and was now aiming to restart the reactor around September. It was previously set for May.

Making a gradual comeback after the 2011 Fukushima disaster, nuclear power is key to Japan's efforts to decarbonize its economy and cut import costs of fossil fuels.

READ MORE: Japan approves restart for nuclear reactor closest to 2011 quake

Nuclear energy has contributed to a reduction in Japan's imports of liquefied natural gas to its lowest in 14 years in 2023.