The three men, all in their 30s, might be any construction workers knocking back Sapporos at a tiny izakaya, or neighborhood bar. Around them is the friendly clutter of any small, working-class drinking place in Japan. Fading calendar portraits of a favorite singer fill every last inch of wall space not given over to bright posters for ocean resorts, photos of kimonoed actresses striking classical poses, or plaques on which celebrities have inscribed their autographs. There’s even a framed snapshot of the old-broad proprietress next to the celebrated tough-guy director and TV star Beat Takeshi.

One patron is missing many of his teeth and has the intense, staring eyes of the slightly too ferocious guerrilla in a samurai movie. Clad in a blue tracksuit and tennis shoes, 34-year-old Hideyaki Kusumoto leans forward and addresses practically the only foreigner to be seen in the town—a small, trim man, dressed in a summery pink sweater and Stabilicore running shoes, with a deep tan and gray appearing along the sides of his thin reddish hair.

“Doctor, I know about the workers in Chernobyl who’ve suffered. Am I at risk?”

“It takes about 30 or 40 years to get cancer from radiation, except among children,” the visiting American says in the calm, clarifying tones of a seasoned physician. “So if workers from Chernobyl have cancer now, it’s probably not because of radiation.”

“But I’m working in a place where the radiation is really high,” says a colleague in thick black glasses, 30-year-old Masaya Ishikawa. “I work two hours a day. I get 1.67 millisieverts every two hours.”

He pulls from his wallet a sheaf of tiny white receipts on which his daily radiation dose at Japan’s Fukushima Daiichi nuclear power plant, crippled by the earthquake and tsunami of last March, is given to him every day. “I know that cancer will appear only 30 or 40 years later, but what about other diseases? What’s the maximum exposure I should get? At what levels of radiation do the white blood cells start decreasing?”

“About 1,000 millisieverts,” says Robert Gale, a hematologist, oncologist, and expert on bone-marrow transplants who has become one of the strongest voices for the controversial position that fear about radiation at Fukushima is overblown.

“So, 250 millisieverts is O.K.?”

“It’s O.K. under these circumstances. But it’s best not to go over that.”

The doors slide open, admitting the warmth of a late-October evening, and two older men dressed all in black, with white shirts and black ties—the kind of dress the Japanese usually favor only for funerals—come in, take the last two seats at the bar, and order Kirins.

Kusumoto leans forward again, well into his third or fourth beer, and says to his new friend, “When you were at Chernobyl, were they wearing protective suits? Should we?”

“You need a balance,” replies the doctor, who has come today for the first time to the hot-springs resort of Iwaki Yumoto, just outside the “exclusion zone” that encircles the nuclear plant with a radius of 12 miles now. “We started out wearing the radiation-protective suits in Chernobyl, but it made us move very slowly, because they’re so heavy. So people ended up getting more radiation because they were wearing these heavy clothes. It was better to work very fast, without protection, than very slowly with protection. In the end, we didn’t wear any protective clothing.”

Ishikawa has already said that he’s come up to work here, helping to clean up the stricken plant, in part because he remembers the earthquake that hit his hometown of Kobe in 1995, killing more than 6,000 people. “Of course the salary is good,” he says, “but I also felt, as a former victim of an earthquake, I should help.”

Now he eyes the doctor again.

“Can my work here affect my family members and friends?”

“A good question. The answer is no.”

“Good. I have four children.”

“The radiation goes through you,” Gale explains. “So when you go home, none of this will affect them. They’re completely safe.”

He pauses for a moment. “We have to think of two kinds of radiation,” he goes on. “This mug of beer is radioactive. Radiation is coming from me. That’s one kind, the most important kind, which is internal. There’s another kind that gets on our skin and is only external. That’s not so important, though it looks as if it should be.”

“It’s like these clothes, right?”

“Exactly.”

“Great! I’m sorry to ask you this. But some friends of mine from Osaka are coming up here to work, and I feel responsible for them.”

The Fukushima 18,000

Ever since the devastating events of March 11 caused three of Fukushima Daiichi’s six nuclear reactors to melt down—and set off fires in a fourth—the workers who have continued to labor in the plant have become a focus of global fascination, all the more so because so little is known about them. When fires broke out in Reactor 4, “the Fukushima 50,” as they were soon dubbed, stayed on to fight them even as 750 of their colleagues were evacuated. Their number soon rose to more than 1,000 and, by this early-autumn day, 18,000 or more have worked in the plant since the accident. The Japanese government handed out bromides and evasions, and the officials of the Tokyo Electric Power Company (TEPCO), which runs the plant, kept changing their story. All the while, laborers worked to clean up the mess in conditions that looked suicidal to some. “They are ready to die,” said Prime Minister Naoto Kan one week after the catastrophe.

The worries about the spread of radiation have hardly abated, but the workers remain all but nameless and faceless; they rarely speak to the press—for fear of being fired—and all that most of us see of them are pictures of virtually extraterrestrial figures in HAZMAT suits and masks clomping around a wasteland eerily emptied of 100,000 people. (It is estimated that more than 19,000 people have died in the disaster.) They’re shedding a little of their anonymity today, though, because word has gotten out that one of the world’s most celebrated experts on radiation has come to talk to them, and to try to put their concerns into perspective. As Gale walks the streets of the small town 115 miles north of Tokyo, one set of workers after another asks to talk to him, if only so they can share their worries as they can with few others—even if his reassurances may echo some of those given by their government. One worker, at the end of a long evening, even wraps Gale in a bear hug, an all but unheard-of show of affection in reserved Japan.

That Gale should be here at all may be the least surprising aspect of the situation. Twenty-five years ago, when explosions at the Chernobyl Nuclear Power Plant spread contamination across the Northern Hemisphere, he reached out to the Soviet government to go and help Soviet physicians deal with the unprecedented disaster. His work with bone-marrow transplants had made him familiar with some of the properties of radiation, and he had been visiting the Soviet Union for more than a decade, initially invited by Russian colleagues who knew of his interest in Russian literature and culture.

Gale’s work at Chernobyl made him one of the few non-Soviet physicians with experience in helping victims of a large-scale nuclear disaster, and, incongruously for a hematologist, something of a celebrity, lauded by the press—and portrayed by Jon Voight in 1991’s Chernobyl: The Final Warning. When, in 1987, two scavengers in Goiânia, Brazil, accidentally opened an abandoned cancer-therapy machine, releasing a dangerously radioactive isotope, cesium 137, Gale was soon on the scene, evaluating patients and treating them with hormones for bone-marrow recovery. After the 1999 nuclear incident at Tokaimura, in Japan, when seven times the permissible amount of enriched uranium was mixed with nitric acid, and two technicians died—the country’s worst nuclear accident prior to last March—he was quickly at the center of things again.

When Fukushima’s reactors began to melt down, Gale was in Japan within a matter of days, re-uniting with his colleagues from Tokaimura. After visiting the affected area, Gale assured the press that there was no danger in drinking a few glasses of water contaminated with radioactive iodine beyond the 300-becquerels-per-kilogram limit set by the Japanese government, and declared that the 50-mile exclusion zone unilaterally suggested by American authorities was excessive.

Since then, he has consistently claimed that people have less to fear from radiation itself than from the panic and misunderstanding it sets loose. He admits that he’s sometimes wrong: though most of his predictions at Chernobyl have played out as expected, he did not foresee the more than 6,000 cases of thyroid cancer that have been found, almost entirely among children under 16 (fewer than 20 so far have proved fatal). “When physicians are quite certain about the advice they give you,” he says with a characteristic dryness, “you can be perfectly certain something is wrong.”

Sixty-six years old, with a bright-white smile and a shy, somewhat distracted manner—at breakfast one morning, he confesses that he hasn’t slept much, because he had to take five scheduled phone calls between 10 P.M. and 3:30 A.M.—Gale is one of those adventurous polymaths who seem to be everywhere at once. He is the executive director of clinical research in hematology and oncology at the Celgene biopharmaceutical company in Summit, New Jersey; has an appointment as a visiting professor at Imperial College, London; still sees patients at U.C.L.A.; engages in scientific collaborations at the Weizmann Institute of Science, in Israel; and spends most of his life orbiting the globe, writing books and papers at a furious rate and offering PowerPoint presentations on radiation and many other topics. As early as the 1980s, colleagues were noting that he was offering pithy sound bites and bold pronouncements to Barbara Walters and Phil Donahue even after he had been reprimanded by the government and placed under investigation by his university for allegedly treating terminal cancer patients with unapproved experimental procedures. (According to the Los Angeles Times, Gale argued that the treatments “were not experiments at all, but simply the best treatment available for hopelessly ill patients.”)

Yet Gale remains determined to combat what he sees as costly and counterproductive hysteria. “There were more than a quarter of a million abortions after Chernobyl,” he says as we drive around Iwaki, “some from as far away as Poland.” None of them should have taken place if they arose out of fear of radiation, he says, but too many people were fatally misinformed: “Ignorance can result in an unnecessary loss of lives.” At Fukushima, at least 14 elderly citizens reportedly died after they were evacuated from their hospital, in the exclusion zone, and then were unable to find proper care.

“If you measure the levels of radiation at the information booth at Grand Central Station,” Gale tells audiences, “it’s higher—because of all the marble and granite in the place—than the levels that are normally allowed to be maintained at a nuclear power plant.” When he’s treating someone with leukemia, he notes, like any doctor, he will often give them, over the course of an hour or two, 5,000 times the radiation levels the workers at Fukushima have been asking him about. And whereas there were 204 cases of acute radiation syndrome immediately after Chernobyl, none has been recorded so far at Fukushima (though two workers died in the tsunami itself, and two others were hospitalized after stepping into radioactive water and being exposed to nonfatal radiation between 2,000 and 6,000 millisieverts). His more fundamental point is that “some guy from Tokyo University who says ‘Everybody is going to die!’ is interesting. But someone who says ‘Let’s compare this figure with that one’ is not.” Many have died from cancer around Chernobyl since the accident, he says; but it doesn’t follow that they died because of the accident.

To many, Gale’s figures, however well documented, may not tell the whole story. One month after the meltdown, the Fukushima disaster was upgraded from a 5 to a 7 on the International Nuclear and Radiological Event Scale, the only accident to have been given that highest rating other than Chernobyl (the accident at Three Mile Island, in 1979, by contrast, merited a 5). One day before Gale spoke with the workers, a study of the Japanese disaster contended that, in the first few days of the meltdown, Fukushima released more radioactive noble gas than Chernobyl by a factor of 2.5. Earlier, Arnold Gundersen, a former nuclear-industry executive who served as an expert at Three Mile Island, had asserted that Fukushima has the potential to release 20 times as much radiation as Chernobyl.

In the weeks immediately before Gale’s recent trip to Iwaki, one worker checked into a hospital after only 46 days on the job and was dead the following morning. The Japanese government lifted its “evacuation advisory” for those living more than 20 miles from the plant, but at the same time radioactive plutonium 238 was discovered in the soil up to 30 miles from the plant. And The New York Times reported, in mid-October, that citizens’ groups had found more than 20 “hot spots” in and around Tokyo contaminated with potentially harmful levels of cesium.

Duty-Bound

As experts debate and speculate about what is still more or less unknowable, workers continue to stream in from across Japan to put in weeks and even months laboring to clean and check the damaged plant. The region around it is now a depleted wilderness of rolling hills and belching factories, even as the Japan National Tourism Organization Web site still extols Iwaki Yumoto as a “former coal-mining area turned into a paradise of everlasting summer.” Taxi drivers tell passengers their own microsievert levels, and locals complain that you can’t eat fish from the ocean now. Going up to Iwaki, I saw for the first time in my 24 years in bustling and jam-packed Japan one train station after another completely deserted at eight P.M.

One evening, in the local laundromat, where giant machines wash clothes in eight-minute cycles, Mitsuo Koyama, an impassive 29-year-old construction worker from an island near Nagasaki, hangs out with his friend Yasuhiro Shibata, a tiny figure with a haunted face and a can of beer in his Mugiwara Pirates warm-up jacket. Both are working in a very dangerous part of the plant, and Koyama wants to ask Gale about the side effects of the medicine he’s been told to take; he absorbs 2 millisieverts a day, he says, which means that he can work only 10 or 12 days before reaching his approved limit of 25, and then cannot work in a nuclear plant again for five years.

Shibata, five years older than his friend, says, “I felt radiation on my arms and on my skin, so I’m worried. I know how to wash and get it off. But if it gets inside my body, I don’t know what to do.”

“If it gets inside,” says Gale, “in two months half of it will be gone—and in two years all of it. Of course, you have to be careful, but it’s not in us forever.”

A worker who wouldn’t give his name or be photographed from the front—he’s a local who (unlike the contract workers) depends on the plant for his livelihood, especially now that Fukushima’s fields have been devastated and its shops often closed—walks Gale up to a hilltop shrine behind the town so that he can talk privately, and expresses his worries about his three-millisievert level.

“Every year in New York,” says Gale, trying to put the man’s mind at ease, “I get the same.”

“Is it O.K. to eat vegetables with a level of 500 becquerels?”

“Well, that’s about the limit. If you eat them now and then, there should be no problem. But if you eat half a kilo a day, then I think you should be careful.”

The large man looks shaken. “I really, really like vegetables,” he says, giving the distinct impression that he does eat—or has been eating—half a kilo a day.

Nearly all these laborers are in desperate need of a job, especially as the events of March capsized an economy just beginning to emerge from years of recession. Some are reportedly offered salaries of around $80 a day; others, in very dangerous spots, $500 an hour. Though most are allowed to put in no more than two hours a day at the plant itself, the whole process—of being bused to the area, clothed, checked, briefed, and checked again—takes up eight hours every day. Many leave their inns at four A.M.

The courage and self-sacrifice involved in such a commitment would win admiration anywhere, but in Japan they carry a special charge; duty and obedience are the country’s sovereign virtues. Nearly every Japanese myth speaks of some heroic figure who risked death rather than let down his lord or his group. Some have likened the Fukushima 50 to the 47 ronin, the leaderless samurai who ultimately had to commit suicide, but only after avenging their fallen master. Others might recall Benkei, the loyal retainer who died on his feet after protecting his lord, Yoshitsune. Six days before Gale meets the workers, I happened to run into a 69-year-old artist from Tokyo, Shinsuke Notomi, who comes from a high-ranking samurai family. “Many people still observe Bushido,” he says, referring to the samurai code. “The more you feel, the less you say. You should be ready to die every day.”

By a sorrowful irony, the prefecture of Fukushima, which can seem a little like Japan’s Idaho (though the third-largest prefecture in Japan, it merits all of 7 pages in an 880-page Lonely Planet guidebook to Japan, about as many as “Eating in Kyoto”), is proudest of its history of self-sacrifice: when a newly strong imperial faction rose up in the mid-19th century to challenge the Tokugawa shogunate, many in Fukushima resolved to fight it to the death. Not just warriors, but women and children took their own lives rather than surrender. The biggest tourist attraction in the prefecture recalls 20 teenage samurai—the “White Tigers”—who, seeing smoke surround their castle in 1868, committed seppuku, or ritual disembowelment. Only one survived to realize that the flames were in fact far away from the building, which held out for another month.

Into the Inferno

One day, as evening falls in Iwaki Yumoto, Yoshiharu Nakata sits in the blueing dusk outside the train station, soaking his thick, scarred legs in a mini-hot-springs bath right beside the entrance. Old women and thin-haired men join the burly, quiet man in the black tracksuit on the small square wooden platform, trousers rolled up to their knees. Iwaki has long been famous for its curative waters.

As he watched the horrors of March unfolding on TV, Nakata tells Gale, he realized that this was the time to rally behind Japan and return to an area he loved already from having worked in a coal plant here.

“At first my wife didn’t want me to come,” he goes on. “She’s from Hiroshima. I couldn’t tell my parents, because I knew they’d be against it. But this is the moment to save the country.”

Nakata, 37, has a big-city poise not visible in most of his colleagues—the business card he hands out identifies him, in English, as president of a construction company back in Osaka, and on the back notes that he can provide “Visiting Care Massage,” “Health Foods Sale,” and “Mineral Water Sales” and also serves as “Grand Sumo Tournament Goeido Campaign Club Director.”

“There are all these strange measurements,” he complains of the radiation monitoring. “It’s hard to understand. Only a specialist could follow them.” As he talks, beads of sweat appear on his brow, the heat rising up from his legs. “I don’t think they should be building more reactors like this,” he goes on, “but that isn’t realistic. So if the government wants to build more power plants, it should make sure this doesn’t happen again.”

He reaches for his black-and-green pack of Marlboros—nearly all the workers seem to smoke—and Gale, beside him, says with a wry smile, “Cigarette smoking is a form of radiation.”

“I know,” Nakata says, nodding respectfully. “Now I’m here, I plan to quit when I go home. I don’t want a CT scan either!”

A little later, they leave the hot bath and go and sit on a bench across the square, next to a life-size statue of a man playing a flute.

“Most people are running away from the scene,” says Gale as darkness falls over a rainbow-colored totem pole, from whose top a cartoon character waves hello. “But you are running towards the place of destruction. To try to be of help. Me too. Either we’re brave or we’re totally crazy.”

Nakata lets out a deep, appreciative chuckle and, looking down, takes another puff.

“Either we’re smart,” says Gale, “or we must be really stupid.”