Eight US Navy sailors are suing Tokyo Electric Power Company (TEPCO) for hundreds of millions of dollars over allegations the Japanese firm lied to them about radiation dangers after a tsunami-triggered meltdown at the Fukushima nuclear plant.

The sailors accuse TEPCO of deceiving their commanders about radiation levels as the aircraft carrier USS Ronald Reagan took part in relief operations following the March 11, 2011 earthquake and tsunami, according to a complaint filed in US federal court in southern California.

The devastating tsunami swamped cooling systems at the Fukushima plant, sending reactors into meltdown and spewing radiation over a large area.

TEPCO and the Japanese government "kept representing that there was no danger of radiation contamination to the USS Reagan and/or its crew, that 'everything is under control, all is OK, you can trust us,'" the sailors' lawyers wrote.

Japanese officials insisted there was "'no immediate danger' or threat to human life, all the while lying through their teeth about the reactor meltdowns" at Fukushima, it said.

The lawsuit charges TEPCO with reckless, negligent behavior and demands it be held liable for exposing the crew members of the aircraft carrier to radiation, as well as for designing a plant that was unsafe.

The suit alleges as the consequences of the nuclear disaster were kept from the crew, it rushed into an area too close to the plant and "the plaintiffs must now endure a lifetime of radiation poisoning and suffering which could have and should have been avoided," it said.

One of the carrier's crew, Kim Gieseking, was pregnant at the time of the disaster and her one-year-old baby daughter is listed among the plaintiffs in the suit.

The sailors are each seeking $10 million in damages, $30 million in punitive damages and the creation of a $100 million fund to cover the costs of medical monitoring and treatments.

In Tokyo, TEPCO said this was the first lawsuit in a foreign court that addresses its handling of the disaster at Fukushima, Kyodo News reported.

"We would like to withhold any comments since we have not received the lawsuit documents," the agency quoted the company as saying Friday.

In October, TEPCO admitted it had played down known tsunami risks for fear of the political, financial and reputational cost.

TEPCO said last month the cost of the clean-up and compensation after Japan's Fukushima nuclear power plant disaster may double to $125 billion.

The company said decontamination of irradiated areas and compensating those whose jobs or home lives have been affected will cost much more than the five trillion yen ($58.1 billion) it estimated in April.