Thousands of engineers and labourers have been lured by higher wages and a sense of duty The sun has only just risen in Iwaki-Yumoto when groups of men in white T-shirts and light blue cargo pants emerge blinking into the sunlight, swapping the comfort of their air-conditioned rooms for the fierce humidity of a Japanese summer. Four months on from the start of the world’s worst nuclear crisis since Chernobyl, this hot-spring resort in north-east Japan has been transformed into a dormitory for 2,000 men who have travelled from across the country to take part in the clean-up effort 30 miles away at the Fukushima Daiichi power plant. Iwaki-Yumoto has come to resemble corporate Japan in microcosm. Among its newest residents are technicians and engineers with years of experience and, underpinning them all, hundreds of labourers lured from across Japan by the prospect of higher wages. They include Ariyoshi Rune, a tall, wiry 47-year-old truck driver whose slicked-back hair and sideburns are inspired by his idol, Joe Strummer. For five days a week, Rune is in thrall to the drudgery of life as a “nuclear gypsy”, the name writer Kunio Horie gave to contract workers who have traditionally performed the dirtiest, most dangerous jobs for Japan’s power utilities. The industry has relied on temporary workers for maintenance and repair work since the nuclear plant construction boom in the 1970s. Now, as then, those from the lowest rungs of Japanese society work for meagre wages, with little training or experience of hazardous environments. “I’ve never thought working at the plant was dangerous,” Rune tells the Guardian after a day’s work, for which he receives 12,000 yen (£95). “And I think my wage is fair for the kind of work I do. It’s more than I used to get driving a truck.” He arrived at Fukushima in early June after seeing an advertisement for labourers in a magazine. His 73-year-old mother knows her son is working in the area, but she has no idea he spends half of every day at the site of Japan’s worst-ever nuclear accident. Rune, who is divorced, generally gets two days off a week, when he travels to nearby Ibaraki prefecture to see his sons. “When I told them about my work the first thing they said was, ‘Please don’t get irradiated.’ They worry, but they also think that what I’m doing is kind of cool.” He says he has been exposed to five millisieverts (mSv) in little over a month – more than double the worldwide average background dose of 2.4mSv a year. While Tokyo Electric Power (Tepco) engineers working inside reactor buildings are allowed an annual radiation dose of up to 250mSv, Rune’s firm has imposed a cut-off point of 30mSv for staff and 15mSv for casual labourers. “I have about two months left before I reach my limit, but I’m hoping they will make an exception and let me work for longer,” he says. The next morning, at 5.45am, the bus is already waiting when Rune emerges from his hotel, where he shares a room with five other workers. Before them lies a 45-minute journey to J-Village, a football training complex, where they will be briefed on their duties for the day before changing into radiation suits, masks and goggles, protective gloves and glass-encased monitors which they must carry with them at all times on site. At 8am they begin the first of two 90-minute shifts at Fukushima Daiichi, separated by a break of similar length. Radiation exposure and heat bring their working day to an end by early afternoon. Rune gave the Guardian a rare insight