Japan's nuclear regulator has officially granted permission for the country's first interim storage facility for spent nuclear fuel to start operating.

The facility in Mutsu City, in the northern prefecture of Aomori, will store for up to 50 years spent nuclear fuel from reactors run by Tokyo Electric Power Company and Japan Atomic Power Company.

The first batch of 69 spent fuel assemblies in a metal container arrived at the facility in September.

The facility operator, Recyclable-Fuel Storage Company, conducted safety checks on the container and other matters through October 11.

On Wednesday, the Nuclear Regulation Authority heard a report from its secretariat that there were no problems with the safety checks.

The authority then decided to issue a certificate giving the go-ahead for operations.

Recyclable-Fuel Storage Company says its person in charge received the certificate and the company officially began operating the facility on the same day.

Local residents have expressed concern that it has not yet been decided where spent nuclear fuel will be transferred after the 50 year-deadline.

The Japanese government plans to move the fuel to the reprocessing plant in Rokkasho Village, also in Aomori Prefecture. But that facility remains under construction and its completion date has been put off repeatedly.

Recyclable-Fuel Storage Company issued a statement pledging to make safety its top priority and to operate the facility with transparency and in line with local demands.