The magnitude-7.4 aftershock that rocked Fukushima Prefecture and its vicinity last week, more than five years after the mega-quake and tsunami of March 2011, triggered fresh nuclear concerns in the Kansai region, which hosts Kansai Electric Power Co.'s Mihama plant in Fukui Prefecture.

The aftershock came as the Nuclear Regulation Authority approved a two-decade extension for Mihama's No. 3 reactor on Nov. 16, allowing it and two others that have already been approved to run for as long as 60 years to provide electricity to the Kansai region.

Residents need to live with the fact that they are close to the Fukui reactors, which are at least 40 years old. Despite reassurances by Kepco, its operator, and the nuclear watchdog, worries remain over what would happen if an earthquake similar to the one in 2011, or even last week, hit the Kansai region.