Japan's industry ministry is considering extending the lifespan of nuclear power plants to beyond the current 60 years to ensure stable energy supplies.

The secretariat of the Ministry of Economy, Trade and Industry presented three proposals on Tuesday.

One is to maintain the current safety rules of limiting the nuclear plant service period to 40 years in principle. The period could be extended by up to 20 years if approved by the Nuclear Regulation Authority.

The other two proposals are aimed at enabling nuclear plants to remain operational beyond 60 years.

One is to simply remove the 60-year cap.

The other is to maintain the cap, but exclude periods when plants were offline, such as for screening by the regulatory body or due to court-issued injunctions, and add those times to the operational periods.

The ministry also suggested having the government decide around 40 years after a plant starts operating whether it can stay online.

The decision would be based on stability of electricity supply, contribution to carbon neutrality and voluntary efforts by the operator to upgrade safety.

Japan's government advocates making maximum use of nuclear plants to achieve carbon neutrality and ensure stable energy supplies.

The ministry hopes to decide on a plan this year.