Japan's last running nuclear reactor is scheduled to go dark on Saturday, marking an extraordinary turnaround for a country that just over a year ago was one of the world's most eager proponents of atomic energy.

The complete shutdown of the country's 50-strong reactor fleet leaves Japan without nuclear power for the first time since 1966, in a stark demonstration of how severely last year's devastating accident in Fukushima has shaken the public trust.

It is unclear how long the nukeless moment will last: Most of the country's reactors had been halted for routine maintenance, but then left offline while their safety was reviewed. The Japanese government is pushing hard to restart two units in western Japan before energy demand peaks in the summer, warning of power shortages if all the reactors, which produced roughly 30% of the country's electricity, stay offline.

Still, both proponents and opponents of nuclear power agree that Japan has seen a sea change in sentiment since the meltdown of three reactors at Fukushima Daiichi blew radioactive particles over much of the northeast and forced the evacuation of about 150,000 people.

"There is no clear nuclear-energy policy now,'' says Tetsuya Endo, a former diplomat who has held top posts at nuclear organizations such as the International Atomic Energy Agency and Japan's Atomic Energy Commission. "We're at a turning point.''

Before the accident, Japanese energy policy called for a "nuclear-powered nation'' that encouraged the funding of new reactors and that planned as much as 40% of its electricity from atomic energy by 2030.

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