The lawsuit was filed in U.S. District Court in San Diego last week against Tokyo Electric Power Co., which is owned by the Japanese government. Plaintiffs include the infant daughter of two of the sailors who was born seven months after the March 2011 disaster.
The sailors served on the San Diego-based aircraft carrier USS Ronald Reagan, which was carrying out "Operation Tomadachi" ferrying food and water to citizens in the city of Sendai in the wake of the earthquake and tsunami.
The sailors claim the Japanese government repeatedly said there was no danger to the carrier crew "all the while lying through their teeth about the reactor meltdowns" so rescuers would "rush into an unsafe area."
The U.S. Navy, the suit said, relied on information from the Japanese government, which only belatedly admitted that radiation had leaked into the atmosphere from the damaged power plant.
The suit claims the sailors were exposed to harmful levels of radiation that could result in cancer and a shorter lifespan, and they are undergoing considerable mental anguish as a result. The sailors are suing for more than $100 million in damages.
"They have physical problems. One of them is bleeding from from his rectum already. The others have problems with thyroid glands," the sailors' attorney, Paul Garner, told KGTV in San Diego.
Garner says one of the sailors now has cancer and recently had a baby with birth defects.
Some of the sailors experienced symptoms while their ship was in Bremerton, Wash., for maintenance and repairs starting in January 2012, a few months after returning from the humanitarian mission.
All of those traits are associated with radiation poisoning - but confirming that these health problems came from exposure to Fukushima nuclear reactor radiation won't be easy.
"I don't think that you can actually prove that," says San Diego State University professor and nuclear expert Murray Jennex.
Jennex says that determining radiation levels in a person, and the direct effects on that person can easily be argued.
"There is no science I know of that their lives are shortened," said Jennex. "But this is something that is way down the road. If it was an immediate exposure risk, they would have known that."
Garner and the sailors say the Japanese government knew exactly how dangerous the situation was and never told the sailor aboard the ship about the risks until it was too late.
"They put out the word that everything is fine, we got everything under control, and they lulled everybody, the world into a false sense of security," said Garner.
An email seeking response from the Tokyo Electric Power Co.'s corporate office was not immediately returned.