Japan's Nuclear Regulation Authority has instructed its secretariat to go ahead with steps to formally reject a plan to restart the Tsuruga nuclear power plant's No.2 reactor.

Regulatory officials compiled a conclusion last Friday that says the plant in Fukui Prefecture, central Japan, is not in conformity with regulatory standards, due to a fault running under a reactor building.

The regulatory standards do not allow facilities where safety is critical to be built over an active fault.

The plant's operator, the Japan Atomic Power Company, asked for additional surveys to expand data on the fault and revisions to the application to restart the reactor.

Regulatory officials on Friday interviewed the operator's President Muramatsu Mamoru about details of the additional surveys.

Muramatsu said the surveys will take more than one year, and that the company will formally present its plan in about two months. He explained the firm plans to revise the application and submit it after conducting the additional surveys.

Noting that the explanation lacked concrete details, the regulatory officials decided not to accept the firm's requests for the additional surveys and revisions to the application in this round of screening.

They instructed the secretariat to draw up a draft assessment saying that the reactor does not meet regulatory standards.

The draft assessment is expected to be compiled in about one month. If formally endorsed, it will be the first time a nuclear reactor has not been allowed to go back online since the current Nuclear Regulation Authority was established in 2012.

In that case, the Japan Atomic Power Company can either apply for a fresh round of screening, or decommission the Tsuruga No.2 reactor.

President Muramatsu told reporters that the firm's basic stance is to aim to restart the No.2 reactor, as the reactor is extremely important for his firm's businesses.