Japan Nuclear Reactor Shut in Latest Risk to Power Supply (2)

A nuclear reactor in Japan was unexpectedly shuttered, delivering a new challenge to the nation’s energy supplies in the middle of winter.

Kansai Electric Power Co.’s Takahama No. 4 nuclear reactor in Japan’s Fukui prefecture was automatically halted earlier on Monday, according to a spokesman. The utility is investigating the reason for the halt, he said.

The reactor automatically stopped after an alarm went off, the nation’s Nuclear Regulation Authority said in a statement. The reactor is being cooled normally and no irregularities have been detected, and a local inspector is checking the plant, it said.

The closure ...