Japan's nuclear regulator has indicated it will likely not lift the order that effectively banned the operation of the Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture by the end of May. The order given two years ago cited a series of security flaws at the plant.

Problems with anti-terror measures surfaced at the plant on the Sea of Japan coast in 2021, after an employee gained improper access to the plant's central control room. Also, sensors for detecting intruders malfunctioned and alternative measures put in place were insufficient.

The Nuclear Regulation Authority, or NRA, has been inspecting how the plant's operator Tokyo Electric Power Company, or TEPCO, has improved the plant's anti-terror measures.

The regulator discussed its interim report at its meeting on Wednesday.

Six issues were raised that remained unresolved, including problems with sensors for detecting intruders. Part of the sensors malfunctioned and failed to transmit signals. Inspectors also observed corrosion.

An NRA official said that TEPCO has not been able to fulfill some of its own targets. The official said it would be difficult to resolve the problems by dealing simply with the hardware.

The authority plans to conduct additional inspections at the plant and compile a report by May to determine whether to lift the effective operational ban on the plant.

In a news conference after the meeting, NRA Chairman Yamanaka Shinsuke stated that it would be tough to dramatically rectify the problems found during the inspection by the end of May, indicating it is unlikely that the regulator would lift the ban by then.