With Sunday's shutdown of Kansai Electric Power Co.'s Oi No. 4 reactor for regular safety inspections, Japan will be without nuclear power for the first time since July 2012.

How long it stays that way is the subject of a political struggle involving local governments hosting the plants, utility customers concerned about price increases, pro-nuclear politicians, and a Nuclear Regulation Authority trying to grapple with the crisis at Fukushima No. 1 even as it faces pressure to divert limited personnel and funds to speed up safety inspections at plants elsewhere.

Sunday's shutdown in Oi, Fukui Prefecture, follows that of the plant's No. 3 reactor earlier this month for regular inspections, which must take place approximately every 13 months.