Japan was running without nuclear power for the first time in 42 years Saturday, as the final commercial reactor in operation was shut down for routine maintenance.
Hokkaido Electric Power Co. gradually started taking reactor 3 at its Tomari nuclear plant offline around 5 p.m., and operations completely halted by 11 p.m.
No reactors shut for regular scheduled checks have gone back online since the triple-meltdown crisis at the Fukushima No. 1 power station in March 2011. All 50 of the nation's viable reactors must now undergo mandatory two-stage stress tests to determine if they can resume operations, a measure introduced amid the nuclear crisis.