Tokyo Electric Power Co. officially declared Wednesday that the two reactors that suffered no major damage at the Fukushima No. 1 plant in the 2011 disaster are defunct, meaning the nation will have only 48 operable commercial reactors.

"With this decision, all of the plant's six reactors will be classified as defunct," Tepco said in a press release following a meeting of its board. "It is extremely regrettable that we hugely betrayed the local people's trust due to the accident and are deeply ashamed of ourselves."

Reactors 5 and 6 will be classified as defunct on Jan. 31, but instead of dismantling them, Tepco may use them as experimental facilities to support the challenging task of scrapping the three reactors that experienced meltdowns and the other one crippled by a hydrogen explosion.