Japan's nuclear power regulator on Wednesday lifted an operational ban it imposed on Tokyo Electric Power's massive Kashiwazaki-Kariwa power plant two years ago, clearing the path for it to resume a process towards a restart.

Tepco has been eager to bring the world's largest atomic power plant back online to slash operating costs, but a resumption still needs local consent in Niigata prefecture, on the Sea of Japan coast.

With capacity of 8,212 megawatts (MW), the plant has been offline since around 2011, when the Fukushima disaster prompted the eventual shutdown of all nuclear power plants in Japan at the time.

In 2021, the Nuclear Regulation Authority (NRA) barred Tepco from operating Kashiwazaki-Kariwa, its only operable atomic power station, due to safety breaches including the failure to protect nuclear materials and missteps that led to an unauthorised staff member accessing sensitive areas of the plant.

Citing improvements in the safety management system, the NRA on Wednesday lifted a corrective action order that had prevented Tepco from transporting new uranium fuel to the plant or loading fuel rods into its reactors - effectively blocking a resumption.

Shares in Tepco had risen sharply after the NRA indicated early this month that it would consider lifting the operational ban after conducting an on-site inspection and meeting with the company's president.