The Nuclear Regulation Authority on Wednesday approved Kyushu Electric Power Co.'s management plans, which are required to operate its reactor at the Sendai plant for more than 30 years.

The approval came days before the unit's planned restart under stricter safety requirements imposed following the 2011 Fukushima nuclear disaster.

The nuclear watchdog endorsed the steps even though Kyushu Electric has not completed all of the procedures, including evaluation of the quake-resistance of some aging instruments. That sparked criticism that the regulator rushed the approval before the reactor's resumption, which is expected as early as next Monday.

Japanese power companies that want to operate their nuclear plants for more than three decades are required to draw up long-term measures to ensure the safety of aging plant equipment. The regulator decided to allow Kyushu Electric to put off completing the remaining steps for one year.

The regulator said the long-term measures can be approved after the 31-year-old No. 1 unit at the plant goes back online. But anti-nuclear activists have intensified criticism of the planned resumption given that not all of the procedures required by law have been completed.

Last September, Kyushu Electric's Sendai plant became the first nuclear facility in Japan to meet new safety standards created in the wake of the Fukushima nuclear crisis, a process necessary before a reactor can go back online.

Safety reviews for the resumption of nuclear plants are conducted separately from those required for long-term operations.