Tokyo Electric Power Company Holdings Inc. said Thursday it has submitted a plan to the nuclear regulator to begin loading fuel in a reactor at an idled plant, northwest of Tokyo, next month, as part of moves to potentially restart the facility. The proposed loading of the No.7 reactor at the Kashiwazaki-Kariwa nuclear plant in Niigata Prefecture from April 15 was submitted to the Nuclear Regulation Authority. TEPCO has yet to restart any of its reactors halted after the Fukushima Daiichi nuclear disaster triggered by the March 2011 earthquake and tsunami. No timeline for a restart has been de…