The proposal comes as Japan rushes to secure enough power generation capacity to meet surging electricity demand, especially for new technologies such as artificial intelligence, data centres and semiconductor factories.

Under the draft plan, as introduced to a panel of experts, the ministry stressed that Japan needs to replace up to five nuclear reactors by the 2040s and a total of around 14 by the 2050s.

The scenario assumes that nuclear would meet about 20 percent of Japan's energy demand during those periods, compared with just under 10 percent now, the ministry said.

"We will promote this initiative with a view to replacing at least this number (of reactors) in order to ensure a stable supply" of electricity, the proposal said.

This is the first time that the government has outlined specific targets for reactor replacement, Kyodo News reported.

Relevant ministers will review the draft at another time, according to local media.

Japan's power industry estimates that by the 2040s, the nation will see a shortfall of 5.5 million kilowatts, roughly equivalent to the power generated by five reactors, Kyodo said.

Japan pulled the plug on all nuclear power after a colossal earthquake and tsunami sent three reactors at the Fukushima atomic plant into meltdown in 2011.

But it now wants to revive atomic energy to reduce its reliance on fossil fuels, achieve carbon neutrality by 2050 and meet growing energy needs from AI.

Before the Fukushima crisis, nuclear used to cover around a third of Japan's electricity needs.