Japan's Tokyo Electric Power Co. (TEPCO) said on Thursday that it has been sued by 157 individuals in a court in the United States for 5 billion U.S. dollars in damages over the 2011 Fukushima nuclear disaster.

The plaintiffs, including crew members on board the USS Ronald Reagan during the 2011 disaster, said the amount would be used to set up a compensation fund for the costs of medical tests and treatment for recovery efforts from radiation exposure they suffered.

The suit, filed on Aug. 18 with the Southern District Court in California, was the second one that hit TEPCO in the United States, following a similar suit filed in 2013 which has 239 plaintiffs registered as of Thursday.

TEPCO, operator of the Fukushima Daiichi nuclear plant, has been hit with a number of lawsuits for alleged negligence or improper design, construction and maintenance of the nuclear facilities.

A local court in Gunma prefecture, central Japan, ruled in March that the Japanese government and TEPCO were liable for negligence in the Fukushima disaster and shall pay a total of 38.55 million yen (352,500 U.S. dollars) to some 137 evacuees from Fukushima in Gunma prefecture for their sufferings.

For another case, the first criminal one after the disaster, three former TEPCO executives appeared in court in June and pleaded not guilty to professional negligence for the fatal meltdowns at the Fukushima Daiichi nuclear power plant in March 2011.

A magnitude-9 earthquake struck eastern Japan in March 2011, triggering a devastating tsunami and killing more than 15,000 people.

The Fukushima Daiichi nuclear plant, operated by TEPCO, was severely damaged by the quake and tsunami and three of its reactors suffered meltdowns due to loss of cooling power, spewing radiation and forcing some 160,000 residents in neighboring areas to flee.

TEPCO, which was bailed out by the government, has been grappling with the lengthy task of decommissioning the plant and carrying out ongoing decontamination and radiation cleanup work which is likely to take decades.