Japan’s nuclear regulators are set to reject a plan to restart the Tsuruga No. 2 reactor, concluding Friday that a fault running underneath the offline unit could be active. It will be the first time the Nuclear Regulation Authority disapproves of a plan to restart an idled reactor under stricter safety regulations imposed after the 2011 Fukushima nuclear disaster. Japan Atomic Power Co. filed an application in 2015 to restart the reactor in the central Japan prefecture of Fukui.