A reactor at the world`s largest nuclear power plant that restarted for the first time since the 2011 Fukushima nuclear disaster is now being shut down again on Thursday due to a glitch that occurred hours after the unit`s resumption, its operator said.

The No. 6 reactor at the Kashiwazaki-Kariwa plant in north-central Japan was reactivated Wednesday night for the first time in 14 years, as plant workers started removing neutron-absorbing control rods from the core to start stable nuclear fission.