Japan is about to be without nuclear energy for the first time since 1970.
Only one of the country's 50 reactors is operating at present at the Tomari nuclear plant in northern Hokkaido, but it is scheduled to stop for maintenance work from 5pm on Saturday for more than 70 days.
There has been lingering public distrust over nuclear energy Since the disaster and all but the one reactor at the Tomari plant are suspended for extra safety checks.
Japan relied on nuclear energy for about a third of its electricity until the earthquake and tsunami last year caused reactor meltdowns at the Fukushima Daiichi plant.
Power companies are increasing their use of thermal plants and gas turbines instead.
Kansai Electric Power has said it could face an electricity shortfall of almost 20% if temperatures are high in July.
There has been lingering public distrust over nuclear energy since the disaster.