A former nuclear worker who developed leukemia after combating the 2011 Fukushima nuclear crisis demanded ¥59 million (around $524,000) in damages from two utilities Thursday at his first trial hearing at the Tokyo District Court.

The 42-year-old man from Fukuoka Prefecture is the first person to be recognized by labor authorities as having an illness linked to workplace radiation exposure since the triple core meltdown at the Fukushima No. 1 nuclear power plant.

The man-made disaster was triggered by the huge earthquake and tsunami on March 11, 2011.

"I worked there because of my ardent desire to help bring the disaster under control but I was treated as if I was a mere expendable laborer," the plaintiff said.

"I want Tokyo Electric to thoroughly face up to its responsibility," he said.

The defendants, Tokyo Electric Power Company Holdings Inc., which runs Fukushima No. 1, and Kyushu Electric Power Co., whose Genkai nuclear plant also employed the plaintiff, asked the court to reject the claim, questioning the connection between his radiation exposure and leukemia.

The man was engaged in welding operations at the Fukushima Nos. 1 and 2 plants and the Genkai complex in Saga Prefecture from October 2011 to December 2013. His exposure in operations subcontracted by the utilities consisted of at least 19.8 millisieverts, according to his written complaint.

The man was diagnosed with acute myeloid leukemia in January 2014 and later went into depression. Both ailments are recognized as work-related illnesses by the Health, Labor and Welfare Ministry.

He said he has been unable to go back to work and is therefore seeking compensation from the utilities.