American rescue personnel believe health problems caused by sailing through radioactive plume.
On March 12, 2011, the day after a huge tsunami hit Japan's northeast coast, the USS Ronald Reagan entered the Sea of Japan on a humanitarian mission.
The massive US$4.5 billion ($5.4 billion) Nimitz-class nuclear-powered "super aircraft carrier", with a ship's company of 5500 men and women, was in the vanguard of a force of 24 US Navy ships, 189 aircraft and 24,000 service personnel deployed to help Japan in Operation Tomodachi.
By then the tsunami, triggered by a magnitude-9 offshore earthquake, had killed 19,000 people and engulfed the Fukushima nuclear power plant, owned by the Tokyo Electric Power Company (Tepco). A catastrophic failure followed, triggering explosions and releasing highly radioactive material into the ocean and atmosphere, as three reactors went into meltdown, the world's worst nuclear disaster since Chernobyl in 1989.
Back on board the Reagan, sailors began the grim, exhausting work of locating survivors amid apocalyptic devastation.
"On that first day, we pretty much immediately started search and rescue," recalls Lindsay Cooper, 34, then an aviation bosun's mate with the 500-strong flight deck crew. It was a frantic time as aircraft were launched and recovered.
"Next thing we know we've got this nasty, metallic taste in our mouth." She says the crew were ordered below. She believes they "had just got slammed by a radioactive plume".
This metallic taste evokes testimony from people who lived downwind of the Three Mile Island nuclear reactor meltdown in 1979 and by airmen on board the US plane that dropped an atomic bomb on Hiroshima in 1945. Cooper believes they passed through other radioactive plumes and describes sailors vomiting and losing bowel control as skin rashes appeared.
"It was a real big problem. We thought gastroenteritis was going around the ship."
Now back in civilian life, Cooper is dealing with ongoing thyroid issues, dramatic weight swings and abnormal menstrual cycles. Other shipmates also have problems she says.
In Washington state, Thomas McCants, 21, copes with what he believes is the legacy of Tomodachi. A gunner's mate on the USS Germantown, McCants joined the vessel, previously part of Tomodachi, in July 2011. Fit when he joined McCants was discharged as unwell five months later. His discharge documents refer to an "adjustment disorder", manifested as stomach pain, weight loss and fatigue. Last October he was diagnosed with chronic myeloid lymphoma. He needs a bone marrow transplant. Are McCants, Cooper and many other young sailors suffering from Fukushima radiation exposure, contacted from atmospheric fallout or from seawater pumped into ship desalination systems? A mass tort lawsuit filed in San Diego last June (an amended suit with around 100 plaintiffs is due to be refiled next month) believes they are and points a finger at Tepco.
"They're suffering from the whole Chernobyl panoply," says San Diego lawyer Paul Garner, who co-authored the suit (the Weekend Herald did not see plaintiffs' medical records and relied on interviews). He says plaintiffs also served on the Essex, Washington, Prebble and other warships. Tepco wants the suit dismissed, arguing the United States has no jurisdiction. Garner says it does because Tepco is registered in California as a foreign corporation.
Garner says many plaintiffs, most in their 20s, have been diagnosed with "cancers, leukaemias, bleeding from vagina and rectum, abnormal growths, loss of eyesight, migraine headaches, weight gain/loss, immunodeficiencies, loss of strength, mobility" and other ailments. The company denies that the Fukushima disaster harmed any US sailors.
Garner contends Tepco knew some 400 tonnes of radioactivity was leaking into the sea each day. He cites the Reagan's deck logs to claim the ship spent five hours sailing through a plume of radioactive material, after steam was vented from the plant in a bid to stop a lethal chain reaction.
"Entered nuclear radiation plume at Lat 37:25 N, Long 144:0 E," says one, entered at 23:45 hours on March 16. Five hours later, at 05:07 on March 17, the log reports, "Exited radiation plume at Lat 37 24.9 N Longitude 143.53.9 E."
The Reagan was later moored at Bremerton, near Seattle, for 14 months before sailing to San Diego, its home port. Garner contends the ship was decontaminated, with debris disposed of at Hanford, a US nuclear dump.
He says Tepco will be "hard pressed" to deny a core meltdown on March 11. "According to [then] Prime Minister Naoto Kan, the meltdown occurred within five hours of the quake," says Garner.
A former nuclear advocate, Kan is now opposed to nuclear power. The complaint alleges Tepco "knowingly and negligently caused, permitted and allowed false and misleading information concerning the true nature of the FNPP [Fukushima plant] to be disseminated to the public, including the US Navy, Air Force and Marines".
"This is a product liability case," says Garner. "They chose to make electricity by boiling water through nuclear power and the tiger got out of the tank."
But even if it can be proven that Tepco was negligent (about one-third of plaintiffs remain on active duty and are legally barred from suing the US), can the plaintiffs show Fukushima caused sailors to become ill?
The official line is that radiation levels were safe, "less than 25 per cent of the annual radiation exposure from natural sources of background radiation, such as the sun", according to navy spokesman Lieutenant Greg Raelson.
The navy says radiation levels were monitored - Cooper describes exiting the flight zone via a decontamination zone and being checked with a geiger counter - and aircrew flying to the disaster zone being given thyroid medicine.
The location of specific ships - and when they were there - may prove crucial in any court case. How close were the US ships to radioactive plumes? How radioactive was seawater used by desalination gear?
Edwin Lyman, a physicist with the Union of Concerned Scientists, says the US Nuclear Regulatory Commission placed ships some 100 nautical miles offshore.
"My understanding is they were very far away from the reactors ... They detected increased radiation levels and retreated."
But Cooper says that at one time she could see land. The lawsuit alleges that "at times" the Reagan was "only a few miles from the failing plant".
At issue may be when the US ships distanced themselves from shore. The suit suggests Tepco's "fraudulent statements" meant that, at first, the navy "failed to take necessary precautions to reduce exposure to radiation".
Lyman thinks Japanese survivors faced greater risks than sailors. The effects of radiation leaking from Fukushima - 300 tonnes of radioactive water reportedly pour into the sea each day - are in dispute, even as reports emerge about problems with thyroid glands in children.
Asked if the impacts of radiation released from Fukushima would be felt by people so quickly, Lyman demurs. "There is a well established body of data on the health effects of radiation exposure. Most solid tumours will not develop for at least 10 years." As for thyroid cancer, he says it began to appear in children exposed to the Chernobyl meltdown after five years.
The US humanitarian response followed a direct request from Japan for assistance. "There was pretty significant debate about estimates of radiation exposure and the implications for US citizens, including those deployed to assist," says Sheila Smith, a senior fellow and Japanese expert at the Council on Foreign Relations, who cites US Nuclear Regulatory Commission data.
"Is it dangerous to our military? To our civilians?" Smith says the navy took a conservative stance, concerned about radiation. "But there's a huge debate about radiation exposure, how quickly it was understood. So it's not just the Ronald Reagan - was it in the right place at the wrong time? - but do we really understand today the extent to which people have been exposed?"
Meanwhile, the US Navy veterans battle on, hoping for relief. Cooper says the Veterans' Administration diagnosed her with post-traumatic stress disorder from the disaster, and prescribed an antidepressant.
She says the threat hit home when she mustered with the Reagan's company to collect gas masks.
"The whole ship was in that hangar bay. It was scary. The navy had no idea what was going on. They didn't know how to handle it. I can't blame them. Had they known the truth I don't think we would have been in that area. We would have maintained a safe distance."