Japan's nuclear watchdog said Wednesday it has lifted its de facto ban on the operation of Tokyo Electric Power Company Holdings Inc.'s Kashiwazaki-Kariwa plant in Niigata Prefecture, more than two years after an order was issued for the improvement of counterterrorism measures.

The Nuclear Regulation Authority confirmed that measures had been enhanced after inspections of the seven-reactor complex on the Sea of Japan coast and hearing from TEPCO President Tomoaki Kobayakawa, but it remains uncertain whether the nuclear plant will resume operation as the trouble-prone utility still needs to obtain local consent.

The Nuclear Regulation Authority holds a meeting in Tokyo on Dec. 27, 2023. (Kyodo) 

"We will listen to residents' opinions and make our decision," Niigata Gov. Hideyo Hanazumi said.

In April 2021, the NRA prohibited the transportation or loading of reactor fuel stored at the plant due to insufficient counterterrorism measures, ordering the utility to take corrective action.

"We want (TEPCO) to take this as a starting line and we will request for continuous improvement" as stipulated in a report on inspections, NRA Chairman Shinsuke Yamanaka said.

Restarting the complex, one of the world's largest nuclear plants by output, is an integral part of TEPCO's restructuring plan to restore its operations following the Fukushima nuclear disaster triggered by a massive earthquake and tsunami in March 2011.

Photo taken from a Kyodo News plane on April 13, 2021, shows Tokyo Electric Power Company Holdings Inc.'s Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture. Japan's nuclear regulator decided on April 14 to effectively ban the utility from restarting the plant due to serious safety flaws. (Kyodo) ==Kyodo

The crisis at the Fukushima Daiichi power plant, the worst nuclear accident since the 1986 Chernobyl disaster, led to the scrapping of the complex as well as TEPCO's Fukushima Daini plant.

The Kashiwazaki-Kariwa plant was found to be vulnerable to unauthorized entry at multiple locations because of defective intruder detection systems and backups, with security flaws discovered since January 2021, according to the NRA.

The security breaches came to light despite the complex's Nos. 6 and 7 reactors having met the NRA's stricter safety standards, imposed after the 2011 nuclear disaster.

The authority confirmed measures to prevent the leakage of radioactive materials had been enhanced through an additional 4,268 hours of inspections, according to the regulators.

Related coverage:

Fukushima nuclear plant worker exposed to radiation

Japan finishes 3rd round of Fukushima treated water discharge

3rd release of Fukushima treated radioactive water begins