A 48-year-old former worker at the Fukushima No. 1 nuclear power plant filed a suit Wednesday demanding ¥11 million in damages from a corporate group led by Tokyo Electric Power Co. for covering up radiation risks associated with his work in the March 2011 triple meltdowns.

The defendants are responsible for having him continue to work, despite knowing the health risks posed by highly radioactive water at the site, according to the indictment filed at the Iwaki branch of the Fukushima District Court.

The man was installing electric cables in the basement of the No. 3 reactor turbine building within the Fukushima No. 1 complex when the massive earthquake and tsunami hit on March 11, 2011.

He claims he was told on March 24 that there would be no problem working at the site, and that radiation exposure was limited to around 10 millisieverts. Radiation levels were later found to have been much higher than 10 millisieverts between March 12 and 31.

Speaking at a press conference in Tokyo, the main said that Tepco failed to properly inform workers of the risks and had an obligation to evacuate them in case of emergency, adding that his legal action is aimed at improving work conditions at the Fukushima plant.

Tepco said it will closely examine the plaintiff's demand and claim.

"It might be the first time a worker dealing with problems at the Fukushima No. 1 plant has filed a suit," the man's lawyer said.