At over 1,000 feet in length and weighing roughly 100,000 tons, the USS Ronald Reagan, a supercarrier in the United States Navy’s Seventh Fleet, is not typically thought of as a speedboat. But on a March day in 2011, the Nimitz-class ship was “hauling ass,” according to Petty Officer Third Class Lindsay Cooper.

Yet, when the Reagan got closer to its destination, just off the Sendai coast in northeastern Japan, it slowed considerably.

“You could hardly see the water,” Cooper told me. “All you saw was wood, trees, and boats. The ship stopped moving because there was so much debris.”

Even after more than 20 years in the service, Senior Chief Petty Officer Angel Torres said he had “never seen anything like it.” Torres, then 41, was conning, or navigating, the Reagan, and he describes the houses, trucks, and other flotsam around the carrier then as “an obstacle course.” One wrong turn, he worried, “could damage the ship and rip it open.”

The Reagan—along with two dozen other US Navy vessels—was part of Operation Tomodachi (Japanese for “friends”), the $90 million rescue, disaster-relief, and humanitarian mobilization to aid Japan in the immediate aftermath of the Tohoku earthquake and tsunami. For the sailors, the destruction was horrific—they told me of plucking bodies out of the water, of barely clothed survivors sleeping outside in sub-freezing weather, and of the seemingly endless wreckage—but the response was, at first, something they’d rehearsed.

“We treated it like a normal alert,” Cooper said. “We do drills for [these] scenarios. We went into that mode.” She and her approximately 3,200 shipmates moved food, water, and clothing from below to the flight deck where it could be put on helicopters and flown to the stricken residents.

But that sense of routine soon changed.

“All of the sudden, this big cloud engulfs us,” Torres said. “It wasn’t white smoke, like you would see from a steam leak,” he explained, but it also wasn’t like the black smoke he saw from the burning oil fields during his deployment in Kuwait in 1991. “It was like something I’d never seen before.”

Cooper was outside with her team, on the flight deck, prepping before the start of reconnaissance flights. She remembers it was cold and snowing when she felt, out of nowhere, a dense gust of warm air. “Almost immediately,” she said, “I felt like my nose was bleeding.”

But her nose wasn’t bleeding. Nor was there blood in her mouth, though Cooper was sure she tasted it. It felt, she said, “like I was licking aluminum foil.”

On March 11, 2011, at 2:46 pm local time, a 9.1 magnitude earthquake struck about 40 miles east of Japan’s Oshika Peninsula. The quake, the world’s fourth largest since 1900, devastated northern Honshu, Japan’s main island. At the Fukushima Daiichi nuclear power plant, located near the epicenter on the Pacific coast, the temblor damaged cooling systems and cut all electrical power to the station—power that is needed to keep water circulating around the active reactor cores and through pools holding decades of used but still highly radioactive nuclear fuel.

Several of the diesel-powered emergency generators at Daiichi kicked in to restart some of the safety systems, but less than an hour after the earthquake a 43-foot-high wave triggered by the quake swept over the sea wall, flooding the facility, including most of the generators, some of which had been positioned in the basement by the plant’s designer, General Electric.

Without any active cooling system, the heat in the reactor cores began to rise, boiling off the now-stagnant water and exposing the zirconium-clad uranium fuel rods to the air, which set off a series of superheated chemical reactions that split water into its elemental components. Hundreds of workers from Tokyo Electric Power Company (TEPCO), the station’s owner, struggled valiantly to find a way to circulate water, or at least relieve the pressure now building in the containment vessels of multiple reactors.

But the die was cast by the half-century-old design, with results repeatedly predicted for decades. The pressure continued to build, and over the course of the next two days, despite attempts to vent the containment structures, hydrogen explosions in three reactor buildings shot columns of highly radioactive gas and debris high into the air, spreading contamination that Japan still strains to clean up today.

And yet, despite this destruction and mayhem, proponents of nuclear power can be heard calling Fukushima a qualified success story. After all, despite a pair of massive natural disasters, acolytes say, no one died.

But many of the men and women of the Seventh Fleet would disagree. Now seven years removed from their relief mission, they’d tell you nine people have died as a result of the disaster at Fukushima Daiichi—and all of them are Americans.

For the sailors on the Reagan who have spoken about it, the reaction to encountering the cloud was bewilderment.

“At first, we were still dialed in,” said Torres. “We didn’t really have a chance to take in what we were experiencing. It was more like, ‘Well, this was different.’” But when he came off watch, sitting in his office, his perception changed to “What the hell just happened?”

Cooper described the same response: “We didn’t really know what was going on.” But after about 10 minutes, the crew was told to go below deck. It was there, as she was first learning about the problems at Fukushima Daiichi from the television, that Cooper recalls hearing an announcement on the public-address system indicating that the ship might have been hit by a plume of radiation from the nearby power plant. Shortly thereafter, Cooper said, the mission got “hectic—just kind of a crazy mess.”

Cooper said the crew hadn’t been warned in advance of any radiation risk, and she didn’t think the Reagan’s commanding officers had any foreknowledge either. But after radioactive contamination was suspected, those aboard the carrier say, everything changed.

Everyone who, like Cooper, had been on the flight deck was ordered to the fo’c’sle, the forward part of the ship, to “implement decontamination.” Cooper said she was instructed to “take anything you can off without getting naked.” She was told to write her name on her discarded clothes and boots—which she saw being piled in the middle of the room—then the crew was “wanded,” as Cooper described it, and given “white, plastic painters’ suits.”

For Torres, news of the radiation came through the rumor mill before he heard about it from his commanding officer. “It was minimal”—that was the impression Torres was given—still, the ship’s meteorologist tracked the wind and talked with Torres about taking the Reagan north of whatever it was they’d just passed through. But Torres was soon instructed to head back toward the coast. They had a HADR, a humanitarian assistance and disaster relief mission, to complete, and since they’d already been exposed—though they’d take precautions such as turning off the ship’s ventilation—they were going back to where they’d encountered the cloud.

It was likely about this time that Cooper recalled being woken up. “I was asleep in my rack when I had someone shake the living shit out of me.” She said she was told with great urgency that she needed to get to the hangar bay immediately to get a gas mask.

As Cooper stood in her pajamas and flip-flops, waiting for her mask and filter canisters, she looked around: “People were shoving wet rags in the cracks of the hangar bay door so none of the air would seep through, and they had rags stacked high along the entire wall,” she said. “It was crazy.”

“After that,” Cooper told me, “our ship went from ‘OK, we got this,’ to, like, ‘Oh, my God… we have no idea what we’re doing.’”

For Marine Lance Corporal Nathan Piekutowski—who arrived several days later with the USS Essex, a Wasp-class amphibious-assault ship—there seemed to be some advanced warning, and he said his preparation initially proceeded in an orderly fashion: “They had us shut all the portholes, all the windows, all the doors.” Piekutowski said they attempted to seal off the berthing area and stayed inside while they headed toward Japan. He was issued iodine tablets—which are used to block radioactive iodine, a common byproduct of uranium fission, from being absorbed by the thyroid gland—and fitted for an NBC (nuclear, biological, chemical) suit. He was also told not to drink water from the ship’s desalination system.

(Those I spoke with from the Reagan said they’d filled out consent forms for iodine tablets, but then never received the pills.)

Piekutowski wasn’t particularly troubled by these precautions. He knew they had plenty of bottled water on the ship, and, by the time they were near the coast, they were allowed back on deck with no special protection. “We were never once told to put on our NBC suits.” He had been issued big rubber over-boots and a gas mask along with the suit. “Those were in sealed plastic, like freezer bags,” he told me. “Mine stayed sealed till we got back to Hawaii.”

Torres, the senior petty officer, recounted, “One of the scariest things I’ve heard in my career was when the commanding officer came over the loudspeaker, and she said, ‘We’ve detected high levels of radiation in the drinking water; I’m securing all the water.’” That included making showers off limits.

Torres described a kind of panic as everyone rushed to the ship store to buy up cases of bottled water and Gatorade—“they didn’t want to dehydrate.”

Cooper also remembers the announcement on the water contamination: “We were like, ‘Are you fucking kidding me?’” She was among those trying to buy bottled water, but said it was quickly taken off the shelves—reserved for “humanitarian assistance.” Instead, Cooper said she was told she’d be issued rations of one bottle of water per day. For the long, hard shifts spent outside, Cooper said it was not nearly enough. She said an attitude set in among her shipmates, “We were like, ‘Fuck that, we’re already exposed—I’m gonna drink the water.’”

“We didn’t know how else to handle it,” she told me. “Like, you’re exposed on the flight deck, you’re exposed in the hangar bay, you’re exposed in berthing, you’re exposed walking, you’re exposed eating—congratulations, now you’re drinking it.”

“You’re working up top for like 18 hours, you’re busting your ass off—you need to hydrate.”

Cooper described her days during Operation Tomodachi starting before dawn and ending after 8 pm, with one 30-minute break for lunch, using the bathroom, and any personal business she could squeeze in. “They didn’t want you coming downstairs too many times because it just took too long,” she said, describing a lengthy and isolating decontamination process that was supposed to keep her and about 20 of her shipmates on the flight deck from spreading radioactive contamination to the rest of the carrier. “If you had to go to the bathroom, you were pretty much shit out of luck,” Cooper said of the time and hassle required to get to the women’s restrooms one floor below deck. “A lot of us females had to hold it in—it was miserable.”

The long hours, the short rations, and the unrelenting tableau of death and destruction drifting by the ship combined with the constant reminders that they were exposed to an unknown amount of radioactive contamination wore on the crew. They felt committed to the mission, and gratified to help, but the threat of radiation presented an aggravating obstacle. “Every time we got close to do humanitarian assistance,” said Cooper, “we’d need to dodge another plume.”

Fukushima Daiichi in Fukushima Prefecture, northeastern Japan, on March 11, 2011. (Reuters / Yomiuri)

Even when operating normally, reactors like the ones designed and built by General Electric at Fukushima Daiichi produce highly radioactive isotopes of noble gases such as xenon and krypton, explained nuclear engineer Arnie Gundersen, who encountered the phenomenon when he worked at the Millstone Nuclear Power Plant in Waterford, Connecticut, in the 1970s. Millstone’s first reactor was a GE Mark 1 boiling-water reactor (BWR), the same model that failed at Fukushima. (Millstone 1 ceased operation in 1998; two other reactors of a slightly different design remain in use at the facility.)

But, as detailed by Gundersen—who is now one of the directors of Fairewinds Energy Education, a nuclear-industry watchdog—superheated “cracked fuel,” like that in the crippled Daiichi reactors, “immediately releases noble gases.”

“And that happens before the explosions” that destroyed the three reactor-containment buildings at Fukushima, he said. As Gundersen sets out the time line of the disaster, fuel began to crack within six hours of the earthquake, and TEPCO’s plant operators would have known it. “They had to know,” he told me, “because when the containment pressure started to go up, that was a clear indication that the fuel was failing.”

So, in those early hours, pressure built inside the Mark 1’s containment vessel to a point where it is thought to have broken the seal on the massive metal lid, and, as plant workers desperately tried to vent some of the gas and relieve that pressure, a radioactive plume formed over the coast.

And as the venting failed and the containments on three reactor units ruptured and exploded, a volume of radioactive xenon and krypton estimated to be about triple what was released in the 1986 Chernobyl disaster, wafted from Fukushima Daiichi over the next eight days. “Eighty percent of the radiation went out to sea,” said Gundersen. “That’s good for Japan, but it’s not good for the sailors, that’s for sure.”

Marco Kaltofen, president of Boston Chemical Data Corporation and an engineer with over 30 years of experience investigating environmental and workplace safety, noted that sensors in Richland, Washington, nearly 5,000 miles across the Pacific, saw a sixfold increase in radioactive noble gases in the days after the start of the Fukushima crisis. Chiba, the prefecture east of Tokyo, nearly 200 miles south of Fukushima, recorded radiation levels 400,000 times over background after the explosions.

Closer to the release, Kaltofen figured, would be orders of magnitude worse. “A bad place to be is a couple of miles offshore,” he said.

When told what the sailors experienced in the earliest days of the operation, Gundersen and Kaltofen differ slightly on their interpretations. Gundersen finds symptoms like the metallic taste consistent with the radiation exposure possible from a plume of otherwise odorless xenon or krypton. Kaltofen thinks that indicates exposure to some of the radioactive particulate matter—containing isotopes of cesium, strontium, iodine, and americium—that was sent into the air with the hydrogen explosions. But both believe it speaks to a notable degree of radiation exposure.

Cindy Folkers agreed. Folkers is the radiation-and-health specialist at the clean-energy advocacy group Beyond Nuclear, and when she hears the symptoms reported by the Tomodachi sailors, she hears the telltale signs of radiation exposure. And when told of what those relief workers experienced next, and the speed with which their symptoms manifested, she said she thinks the levels of exposure were higher than some have reported—or many would like to admit.

Just what the two large companies responsible for the design and operation of Fukushima Daiichi—TEPCO and GE—will admit is at the center of a pair of lawsuits currently moving through US courts. Or at least should be, if and when it gets in front of a jury.

“We’re still trying to get to the merits,” attorney John Edwards, the former US senator and Democratic vice-presidential nominee, told me, “because the merits of the case are so strong.” Edwards, along with attorneys Cate Edwards (his daughter) and Charles Bonner, represent what Bonner told me were now upward of 400 sailors who accuse the Japanese utility and the US industrial giant of gross negligence in the design, construction, maintenance, and operation of the Fukushima Daiichi nuclear power plant, and of deliberately obscuring the radiologic disaster that rapidly unfolded after the March 2011 earthquake and tsunami.

And if that were all there was to it, many who have examined the Fukushima disaster—including the Japanese government’s own investigation, Japan’s prime minister at the start of the crisis, Naoto Kan, and even TEPCO itself—would say the plaintiffs have a point.

Before the first of the Daiichi reactors was brought online (construction began in 1967, and operation commenced in 1971), there were already open concerns about its design and placement. Originally conceived in the 1950s, the General Electric BWR Mark 1 was thought by some of its own designers to have too small a containment structure to survive a prolonged LOOP—a loss of onsite power. The ability to adequately vent the containment was also called into question, as was the resilience of the containment vessel’s metal alloy. In 1976, three GE engineers who had worked on the Mark 1 quit to protest the manufacturer’s lack of urgency in addressing flaws they said would cause reactor containment to fail in a loss-of-cooling accident.

In readying the site for Fukushima Daiichi, TEPCO opted to cut down the natural 115-foot sea wall, to less than 33 feet, to reduce construction costs and make it easier to access seawater for cooling. The emergency cooling systems were also placed close to shore and did not use submersible pumps. That whole facility was placed behind what was originally only a 13-foot-high sea wall (later raised to nearly 19 feet), despite evidence that eight tsunamis of at least 40 feet had hit the area in the 70 years prior to the agency’s breaking ground on Daiichi. Many emergency generators were situated in the basement, and diesel-fuel tanks were placed on a flood plane, leaving them vulnerable to the massive wave that slammed the site in 2011.

Within two years of the containment breaches, Kan, by then the former prime minister, was telling experts and investigators, including nuclear engineer Gundersen, that TEPCO had withheld critical information about what was happening at Fukushima in the first hours and days of the crisis. In 2016, TEPCO was forced to admit it failed to publicly declare a meltdown at the three crippled reactors, even though its internal guidelines indicated from early on that meltdowns were indeed occurring. And just last spring, a Japanese court found TEPCO (along with the government) guilty of negligence, not just in handling the disaster but also, in the years prior, in declaring the events at Daiichi “predictable” and preventable.

But none of that has been heard by a US jury. For over four years, a number of sailors, Marines, and other military-relief personnel have waited for their day in court while their attorneys wade through motions from the defendants, GE, and TEPCO, challenging venue and jurisdiction.

In an e-mailed statement, General Electric, while expressing “heartfelt sympathy for those affected by the earthquake and tsunami,” and appreciation for “the hard work and dedication of our US service members,” said claims “can and should be addressed under Japan’s nuclear compensation law.” TEPCO also “appreciates the plaintiffs’ service on Operation Tomodachi,” according to its e-mail, but declined to comment outside of court on pending judicial actions. TEPCO did add, “It is most unfortunate that some of the plaintiffs are ill.”

Ruby Perez was a 22-year-old petty officer first class on the Reagan during Operation Tomodachi. She was also pregnant. Perez told her mother, Rachel Mendez, about the snow falling during the first days of the operation. She and her shipmates were excited by a moment of diversion from the misery around them. As Mendez relayed her daughter’s story to me, “They were playing in it, eating the snow, making snow cones, making snowmen.”

Cooper, part of the flight deck crew, remembers the snow, too, though not so much as a light moment but rather as a symbol of decaying morale. After days of long hours and short rations, feeling isolated from the below-deck crew, knowing she’d been exposed to some radiation, she felt “knocked down.”

“Nobody really cared about anything. People were making radioactive snowmen on the flight deck out of radioactive snow,” she said. Dealing with the contamination and the stress “completely changed the dynamic of the ship.”

An official in protective gear checks for signs of radiation on a child who was evacuated from an area near Fukushima on March 13, 2011. (Reuters / Kim Kyung-Hoon)

“Stress” was what the Reagan’s medical staff told Cooper when she asked about her blurred vision, poor depth perception, and loss of equilibrium during the early days of the mission.

“Gastroenteritis” was what she and many of her shipmates were told as a wave of bowel problems swept through the carrier over the next several weeks.

“I had a lot of issues with the restroom,” Cooper told me. “I don’t think I was the only one. People would shit themselves on the flight deck so often that it wasn’t even a surprise anymore. Like when you saw someone running from one side of the flight deck to go to decon[tamination], you knew something was happening.”

Torres’ experience was comparable. “I was going to the bathroom constantly,” he said. “I would eat something and I would go to the bathroom almost immediately.” It happened so often, Torres told me, that he developed severe internal hemorrhoids that eventually required multiple surgeries.

But when he visited the shipboard doctor, Torres was told he had diverticulitis, a disease not typically seen in men that young. “Watch your diet, don’t eat spicy food, and drink lots of water, eat lots of fiber,” that was the advice he said he received.

Cooper heard much the same: “Stay hydrated—drink water and eat a bland diet.” But the symptoms didn’t subside. “They didn’t attribute it to anything except ‘it’s going around,’” she said. But if that’s so, it’s been going around a long time. “I haven’t had a solid bowel movement since,” said Cooper.

Soon after Operation Tomodachi ended, when the Reagan ported in Bahrain, Cooper, who was 21 at the time, noticed her hair thinning. “I used to have really, really thick hair,” she said, but in Bahrain it became brittle and started falling out. Cooper said it still hasn’t recovered.

She also told me she now bruises easily and gets “burning, tingling sensations” on her arms, and a rash that extends from her hands to her elbows—an area that coincides with where she’d had her sleeves rolled up when she encountered the cloud at the start of the Japan mission. Cooper has also recently needed veneers on teeth she said have started to “shatter and break.”

For Piekutowski, the lance corporal from the Essex, he didn’t feel particularly sick until over a year after Operation Tomodachi. He was back stateside in the fall of 2012, and felt fatigued and had lost weight, and in November of that year, his ankles swelled up to the size of his calves. “I’m an in-shape and slim guy, and usually have pretty good definition,” he told me. His doctor thought it might be gout, though Piekutowski was skeptical. “I told him, I drink as much as the next 21-year-old, but I don’t drink that much.” Then, on Christmas Day, he lost the sight in his left eye. “That’s when I knew I should probably get to the hospital,” he said.

In the ER, Piekutowski said the doctors seemed to recognize right away what a blood test and bone-marrow biopsy later confirmed: He had leukemia. “They were honestly surprised I was still walking,” he said. Medical staff put him in a gown and rushed him to a bigger hospital.

Piekutowski was diagnosed with acute myelogenous leukemia (AML), an aggressive form of blood cancer most often seen in men over age 65. It is rare to see it in an otherwise healthy 21-year-old. He began treatment in Arizona, where he’d been living, but then moved to Chicago to be closer to his parents and what Piekutowski called “some pretty amazing doctors.”

From Christmas 2012 to Valentine’s Day 2014, Piekutowski figures he spent eight months in hospitals. He first went through a year of chemotherapy, but after four months in remission, his leukemia returned. He had radiation and a stem-cell transplant at the start of 2014, which has so far kept him cancer-free. But Piekutowski is still struggling to rebuild his immune system, and battling stiffness and stomach problems. “I feel like I’m 60,” he said.

Petty Officer Perez gave birth to her daughter Cecilia on March 26, 2011, and it was soon afterward that she told her mom she was feeling ill. “She just kept saying her menstrual periods would keep going and going and never stop,” said Mendez.

Despite her health, she reenlisted at the end of her tour. She was in San Diego trying to sort out some missing paperwork on her enlistment when she was hospitalized for a uterine hemorrhage. According to her mother, Perez was diagnosed with late-stage ovarian cancer in July 2016. Mendez wanted her daughter to come back to Texas, where she grew up, but Perez refused. She always believed she’d get better. “I can’t go home,” Mendez said Perez told her, “I just reenlisted. I still owe the Navy two years.”

On December 7, 2016, Ruby Perez died.

Perez is one of the eight deceased service members represented in the suits slowly making their way in US courts. Her daughter Cecilia, whose health will require a watchful eye well into adulthood, is also a plaintiff. So are 24 men and women currently living with various forms of cancer. So is a sailor whose son was born with brain and spinal tumors and lived only 26 months.

“We have a lot of clients with bone and joint issues, degenerative discs,” Cate Edwards told me, “young, healthy, active individuals who have trouble walking now.”

The most prevalent ailments, according to the younger Edwards, are thyroid-related. Thyroid cancers are some of the earliest to emerge after nuclear accidents because of the easy pathway for absorption of radioactive iodine. Childhood thyroid cancers skyrocketed in Belarus, Russia, and Ukraine in the first two decades after Chernobyl. According to a study published in the journal of the International Society for Environmental Epidemiology, individuals who were 18 or under at the time of the disaster in Fukushima Prefecture were 20-to-50 times more likely to be diagnosed with thyroid cancer in the period between the March 2011 and the end of 2014.

And health experts will tell you it is still too early to see many of the cancers and other illnesses that increase in incidence after exposure to ionizing radiation. Some can take 20 or 30 years to emerge. “That these sailors are getting the health effects they are already experiencing tells me that the radiation levels were extraordinarily high, and that we are likely just seeing the tip of the iceberg,” said nuclear-engineer Gundersen. “I think we’re going to see more of these people in the same boat as this initial wave of hundreds.”

“I can’t believe in a couple of years,” he added, “we won’t have thousands.”

Which is why, Cate Edwards told me, everyone who was part of Operation Tomodachi, even those who haven’t yet been diagnosed with particular ailments, are going to need additional medical monitoring for decades to come.

But General Electric and Tokyo Electric Power contend that these US citizens, from the US armed forces, who served on US ships, should seek their legal remedies in Japanese courts. “We believe these claims can and should be addressed under Japan’s nuclear compensation law, which provides relief for persons impacted by these events,” said GE in its e-mailed statement. (TEPCO did not respond specifically to a question about venue.)

The plaintiffs’ lawyers dismiss this idea. “It’s the difference between winning and losing,” John Edwards told me. “If the case ends up in Japan, it just goes away.”

The Edwardses and Bonner paint a picture of a Japanese legal system that is slanted in favor of industry. “You don’t get a jury trial in Japan,” said Bonner. “You don’t get punitive damages. Plaintiffs have to pay exorbitant fees to have their cases tried before politically involved judges,” and are not allowed to seek recovery of court costs, he said.

John Edwards added that Japan rarely awards damages for pain and suffering, loss of life, or the effects on a family. “They have an established compensation system,” he said, “they have never paid a dime for personal injury—it’s all for property damage.”

Indeed, while there were rulings in Japan’s courts last year against TEPCO and in favor of Japanese citizens, the awards were notably small (averaging $5,400 per person in one case, $1,500 in another), and were meant as compensation for residents of towns surrounding the nuclear plant who had to relocate. In a separate case in February, a Japanese court ordered TEPCO to pay $142,000 to the family of a 102-year-old man who killed himself after being told he’d have to leave his home inside the Fukushima radiation zone. TEPCO is still considering whether it will appeal.

One group of Tomodachi plaintiffs has been cleared to proceed in the US by the US Court of Appeals for the Ninth Circuit. A second group is still fighting in San Diego to establish jurisdiction in California courts, a hurdle all three of the plaintiffs’ attorneys are confident they will eventually clear.

And when the merits of the case have their day in a US court, “the only real defense,” for TEPCO and GE, said John Edwards, “is to try to argue, ‘Yeah, we screwed up, we know it was bad, but is that what really caused what happened to these people?’” In other words, the defendants will concede there was a disaster at Fukushima Daiichi, but will contend the plaintiffs weren’t harmed by it.

There are pretty strong indications that just such a defense is in the works. TEPCO spokesman Shinichi Nakakuki asserted in an e-mail to me that “objective scientific data demonstrates that plaintiffs were not exposed to amounts of radiation from the Fukushima Daiichi Nuclear Power Plant sufficient to cause illness.” Nakakuki wrote that radiation estimates by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) “confirm that the doses received by the plaintiffs were below the level that would give rise to adverse health effects.” The spokesman also referenced a report submitted by the US Defense Department to Congress in 2014 that downplayed the link between service on the Reagan during Operation Tomodachi and the specific cancers that had then emerged among crew members.

Time is one of the keys to understanding both of these reports. The Defense Department looked at the cancer rates only three years removed from the service members’ exposure, far too short a period to predict future numbers, according to radiation-expert Folkers. The UNSCEAR paper is even older than the DoD testimony, and has been roundly criticized for attempting to make bold predictions based on a small window and data extrapolated from analysis of Hiroshima and Nagasaki (which, aside from being drawn from a radically different exposure scenario, has itself been called into question by doctors and epidemiologists). UNSCEAR also appears to have averaged exposure over the entire island, not accounting for the notably higher exposures of those closest to the Daiichi reactors, according to analysis from Folkers’s Beyond Nuclear.

Dr. Keith Baverstock, the former chief radiation-protection expert at the World Health Organization who studied the Chernobyl disaster, said at the time that the UNSCEAR report was “not qualified to be called ‘scientific,’” and questioned the panel’s impartiality because its funding and membership came from the countries with the largest nuclear-power programs.

All of the radiation experts interviewed wondered whether the true scale of the radiation doses sustained by the Tomodachi sailors was ever measured. Safety specialist Kaltofen argued that most measurements don’t account for what are called “hot particles”—minute bits (6 to 9 microns in diameter) of intensely radioactive matter that can be extremely dangerous in close proximity, or if ingested, but are easily missed by measuring devices mere inches away. He also pointed out that different tissues are vulnerable to different isotopes in different ways, and that some parts of the body are much more sensitive to exposure than others. “One of them is the bowel,” he said, “because your intestines have villi, which are rapidly reproducing cells, and that means that they are extremely susceptible to radiation.” If radiation were ingested, or if the gut were exposed to a large external dose, you could see signs of real damage.

These are deterministic signs of radiation exposure, said Kaltofen, meaning you get a specific biological effect that might not itself be cancer, but would indicate the size and kind of exposures that could cause cancers later on. Folkers, discussing the sailors, put it more starkly: “The people in this case might be the dosimeters.”

Gundersen’s experience with radioactive noble gases led him to make another observation about dose estimates. Unless measurements were taken during those first days when ships were likely cloaked in plumes of radioactive xenon and krypton, the exposure would be missed, thus contributing to far-lower-than-accurate dose assessments. “Gases don’t show up on swipe tests, or anything like that,” he said. (Again, this level of methodological detail is not evident in the studies cited by TEPCO.) And Folkers stressed that the increased sensitivity to radiation seen in women and children is not part of most exposure models.

Folkers told me that there is a blood test that could more accurately estimate individuals’ exposures. Karyotyping, mapping chromosomes to look for specific abnormalities closely tied to radiation damage, has been around for decades, she said, but is too rarely done. (No one interviewed for this story believes karyotyping was done on the participants in Operation Tomodachi.) Folkers said that the tests are not only capable of predicting some future illnesses; they can also be used to extrapolate backward to determine the time and intensity of suspected radiation exposure.

But that level of specificity is not the argument lawyers expect in court, nor is it the standard public-health experts would say is appropriate. “Definitive cause is not the standard for protecting public health,” said Folkers, “association is the standard.”

In the case of the Tomodachi sailors, there was exposure to radiation, even if there is some dispute over the size and kind of dose any particular individual received. There are a number of symptoms and illnesses, long associated with radiation, that have been reported in the service members. If people are sick, would doctors, epidemiologists, workplace-safety experts, or public-health officials wait for absolute certitude of a causal link before implementing treatments and preventive actions?

Folkers and Kaltofen each said they would not. Even Petty Officer Cooper’s experience showed that the Navy—whether or not it acknowledges this now—had a basic recognition of this standard. “When you went down there,” she told me about her trips to the medical station on board the Reagan, “you were supposed to tell them if you were on the flight deck.” Depending on the answer, said Cooper, you might have seen a different doctor. “As soon as you said [where you worked], then, pretty much, they knew your issues.”

Cooper had actually reenlisted after Operation Tomodachi, but when the Navy told her “‘OK, you’re gonna do another sea tour with the Reagan,’” she said her response was “Nonononononono.” She told me she didn’t want any possible additional exposure to radiation on a ship she saw as contaminated from stem to stern. Cooper “took the hit” and applied for an “early out” from her reenlistment.

And the Navy, according to Cooper, “fast-tracked an early out because they understood.” Asking off the Reagan became so common, she told me, that there was a little “cheat sheet” on how to expedite the paperwork. “An early out would normally have taken me six months,” she said, “but they got it done in like two weeks.”

Cooper said that because her commanders were there, they understood what she’d suffered through after the radiation exposure, and knew the toll it took on the Reagan’s crew. “That deployment took a lot out of people,” she said. “A lot.”

For Torres, readjusting to civilian life after 27 years in the Navy was made much more difficult because of his post–Operation Tomodachi health problems. His own gastrointestinal difficulties, surgeries for hemorrhoids and hernias, and low-energy levels when he returned stateside deeply affected his mood and his relationships. Torres also said he feels guilt over “the young 17-, 18-year-old kids standing outside,” having to watch them “getting directly exposed” to the radioactive fallout as he stood inside conning the ship. “I have a lot of conflicted feelings,” he told me. “Could I have done something more? All these ‘what ifs.’”

There are plenty of “what ifs” to go around, but Torres is probably one of the last people who should feel guilty. Sure, Cooper now expresses regret for drinking too much of the ship’s tainted water. Piekutowski wishes he’d found a way to avoid spending five days exposed to the elements without any protection. Even Rachel Mendez, mother of Ruby Perez, wonders if she shouldn’t have been so encouraging when her daughter decided to join the Navy.

And some who served question if the Navy did all it could to protect its personnel (though not all, and not all the time). Did the Reagan spend too much time too close to shore? Did commanders always put the health and safety of sailors first when addressing the contamination of the ship and the water system? Did the US military measure properly for radiation, or perform the right tests for exposure? Are they doing all they can now to track the health of, and to care for, the Tomodachi veterans?

Watchdogs and health experts will tell you those are valid questions—especially if they better ensure the well-being of all the sailors going forward—but the attorneys will say that, while the military and the VA have responsibilities for the medical care of service members and veterans, “they are not, in a legal sense,” as Cate Edwards told me, “responsible for the exposure itself.”

(The Navy, for its part, said in an e-mailed statement that it has “a long distinguished history with the successful management of its occupational ionizing radiation exposure program.” It acknowledged some risk from radiation exposure at any level, but said the risks borne by the Reagan sailors were “small compared to other risk” accepted in work and everyday life. In making this assessment, they cite the same 2014 Defense Department report referenced by TEPCO.)

“The end of the road is not the VA,” said John Edwards. The main issue, as Edwards put it, is, “If you’re going to have nuclear plants, make sure they’re designed, built, maintained, and monitored properly.”

And the question of whether TEPCO and GE did do those things properly is not just of interest to the sailors or the residents of northern Honshu—in the minds of all the attorneys and experts interviewed for this story, it is of keen relevance to tens of millions of people living in the United States.

“There’s an obvious connection between what happened in Japan and what could happen in the United States,” said John Edwards. “What they failed to do in the manufacture and maintenance of the facility in Japan also occurred, and is occurring, in the US.”

There are currently 99 operating civilian nuclear reactors in the United States, and 22 of those are General Electric Mark 1 boiling-water reactors—the make and model identical to the three that melted down and exploded at Fukushima Daiichi. Based on a 1955 design, all but four of the US reactors have now been online for more than 40 years. All of them have the same too-small primary containment vessel, the same questionable alloys, the same bolted-on lid, the same safety systems, and (with one exception) the same vent “upgrade” that failed to prevent the tragic failures at the Japanese nuclear plant. Large US cities, such as Boston, Chicago, Detroit, Philadelphia, and Washington, DC, are all closer to BWRs than Tokyo is to Fukushima Daiichi.

“It starts with the design,” Cate Edwards told me, and the complaint filed on behalf of the Tomodachi sailors goes into great detail about the flaws on the Japanese reactors that mirror the ones in the United States. “Each one of these Mark 1 BWRs is defective,” said Bonner.

For Folkers, the lesson is to look at nuclear power plants through the lens of public health. Don’t wait until after an incident to argue over which illnesses might or might not have been caused by a particular dose. Instead, Folkers urged, establish baselines for what the population’s blood work and chromosomes look like beforehand. Then, instead of only starting the fact-finding after an accidental release of radiation, or when a mysterious cancer cluster emerges—when too many vested interests invoke “what-aboutism,” as she called it, to obscure responsibility—already-informed public officials and medical professionals can focus on the response to emerging health problems.

For Kaltofen, the environmental-safety expert, the focus should be on prevention and planning before treatment and tracking. “It’s very hard to come up with a response plan after the fact,” he said.

And, most importantly, for the sailors, Marines, and pilots who rushed into harm’s way to provide emergency aid and humanitarian relief to people battling a devil’s trident of disasters, the acknowledgment of their radiation exposure and the acceptance of responsibility by those who caused it could potentially be as life-changing as their service in Operation Tomodachi.

Sure, it might mean a measure of financial compensation were they to win a settlement, but for the sailors who spoke to me, that would be secondary. Foremost, a victory in court would mean a degree of respect for what they did, how they’ve suffered, and what they might need down the line—not just for those who are ailing today but also for the potentially thousands who might get sick in the future. As Angel Torres told me, “Set up an infrastructure to address those issues. Do the right thing and provide for people that were misled. Let them know, ‘You are not alone.’”