Representatives of Tokyo Electric on Monday began visiting about 41,000 households around its idled nuclear plant in Niigata Prefecture to apologize for withholding vital safety information about a facility there.

The utility, which also runs the meltdown-hit Fukushima No. 1 power plant, is pushing to restart its giant Kashiwazaki-Kariwa plant in Niigata. But residents were angered after learning Tepco had failed to disclose since 2014 that its emergency response center had poor quake-resistance.

Tokyo Electric Power Company Holdings Inc. filed for a state safety assessment of reactors 6 and 7 at the Kashiwazaki-Kariwa plant in September 2013. All reactors across the country have to satisfy new safety requirements introduced after the 2011 Fukushima nuclear crisis.