To a world that doesn't know him, Shingo Kanno is one of the "nuclear samurai" – a selfless hero trying to save his country from a holocaust; to his family, Kanno is a new father whose life is in peril just because he wanted to earn some money on the side doing menial labour at the Fukushima nuclear plant.

A tobacco farmer, Kanno had no business being anywhere near a nuclear reactor – let alone in a situation as serious as the one that has unfolded after the 11 March earthquake and tsunami in Japan.

His great-uncle, Masao Kanno, said: "People are calling them nuclear samurai because people are sacrificing their lives to try to fix a leak. But people like Shingo are amateurs: they can't really help. It shouldn't be people like Shingo."

Masao Kanno is one of more than 500 people camped out on the hardwood floors of a sports centre in Yonezawa. The homes of most of them lie within 19 miles of the Fukushima plant. They worked at the plant, have family members who did, or passed it daily on the way to work or school.

Before, they rarely thought about the down side to that proximity; now it rules their lives. Many of their homes are inside the evacuation zone, with radiation 17 times higher than background levels and tap water too contaminated to drink.

Those with a close personal connection to the crisis, like Masao Kanno, are moved and grateful for the personal courage of the 500 or so workers still at the plant. But where Japan's prime minister and others have conjured up cardboard heroes, he sees a flesh-and-blood relation.

Shingo Kanno, who had been hired to do construction work, was released from his duties at Fukushima soon after the declaration of a nuclear emergency. As the crisis at the plant worsened, and the Japanese government widened the evacuation zone, he moved his wife and his infant daughter to his in-laws, where they would be safer.

He also helped evacuate his extended family from their home town of Minamisoma, which is within the 30km exclusion zone, to the sports centre and other shelters. Then, his relatives say, Kanno got a call from the plant asking him to go back to work.

His whole family took turns getting on the phone to tell him not to go. They reminded him that he was a farmer, not a nuclear engineer, that he did not have the skills for such a sophisticated crisis. They said he should think of his responsibilities to his parents and his baby daughter.

"I told him: 'You have a family now. You shouldn't be thinking about the company – you should be thinking about your own family,'" said Masao Kanno.

But on Friday Shingo Kanno went back anyway. The family have not heard from him since.

In the meantime, the cult of the nuclear samurai has only grown. Japanese television aired an interview with a plant worker on Monday offering a harrowing insider's account of the struggle for the reactors.

The worker, his face hidden from view, described sirens blaring, billowing smoke, explosions so powerful the earth rumbled, water sloshing in the pool of spent atomic fuel. Then he touched on his own complicated emotions before pulling out of the plant. "The people left behind – I feel really sorry for them," the worker said. "It was a hard decision to make, but I had a strong feeling that I wanted to get out."

Such scenes stir powerful emotions in this sports centre, where evacuees are re-examining their own relationship with the Fukushima plant.

"I think you could say those nuclear workers have been brainwashed," said Keiichi Yamomoto, who used to visit the plant regularly for business. "Japanese people are used to focusing their whole lives on their company, and their company takes priority over their own lives."

He said the power company had a policy of locating nuclear facilities in sparsely populated areas with little local industry. Local people got jobs; the power company was able to increase its supply of electricity for Tokyo.

The Japanese government assented to the Fukushima plant; the prefecture government assented to it; even local people assented to the plant, when they took jobs as inspectors there, Yamomoto said. "It was a trade-off."

Now they are experiencing the consequences of that assent.

People who built their lives around the nuclear plant without ever fully acknowledging its presence are now signing up for text updates of radiation readings from their home town.

Some evacuees in the sports hall say they cannot rely on the power company to give them accurate information. They are going to wait for the Japanese government to issue an all-clear before they consider returning home.

Others are wondering whether they are also somehow culpable in the disaster. Yoshizo Endo moved to live near the plant in 1970, when he became one of the first workers at the then newly opened Fukushima.

He spent more than 20 years as an inspector, undergoing regular safety exercises: fire drills, earthquake evacuations. But, he said, they never contemplated the prospect of a nuclear disaster. "Looking back, it's easy to say now that we should have thought of that," he said.

His wife, Tori, said the crisis at the plant, and the struggle of the nuclear workers, had made her increasingly uncomfortable: her husband had made a good living for years at the plant, and they were living on his pension even now. "I feel guilty," she said.

Had Endo been called, he would have gone too, albeit as part of a team, he said. But he added: "I can't really do anything in this kind of situation. The only thing I know how to do is hold a thermometer."

Did he think the nuclear samurai would succeed in taming the reactors? "What will be will be," said Endo.