be needed to maintain the system that cools damaged fuel rods in the reactors with thousands of tonnes of water every day. The contaminated runoff is then transferred to more than 1,000 tanks, enough to fill more than 130 Olympic-sized swimming pools.
Dismantling the Fukushima Daiichi plant will require maintaining a job pool of at least 12,000 workers just through 2015, according to Tepco's blueprint. That compares to just over 8,000 registered workers now. In recent months, some 6,000 have been working inside the plant.
The Tepco hiring estimate does not include the manpower required for the government's new $330 million plan to build a massive ice wall around the plant to keep radiated water from leaking into the sea.
"I think we should really ask whether they are able to do this while ensuring the safety of the workers," said Shinichi Nakayama, deputy director of safety research at the Japan Atomic Energy Agency.
Japan's nuclear industry has relied on cheap labour since the first plants, including Fukushima, opened in the 1970s. For years, the industry has rounded up itinerant workers known as "nuclear gypsies" from the Sanya neighbourhood of Tokyo and Kamagasaki in Osaka, areas known for large numbers of homeless men.
"Working conditions in the nuclear industry have always been bad," said Saburo Murata, deputy director of Osaka's Hannan Chuo Hospital. "Problems with money, outsourced recruitment, lack of proper health insurance - these have existed for decades."
The Fukushima project has magnified those problems. When Japan's parliament approved a bill to fund decontamination work in August 2011, the law did not apply existing rules regulating the construction industry. As a result, contractors working on decontamination have not been required to disclose information on management or undergo any screening.
That meant anyone could become a nuclear contractor overnight. Many small companies without experience rushed to bid for contracts and then often turned to brokers to round up the manpower, according to employers and workers.
The resulting influx of workers has turned the town of Iwaki, some 50 kilometres (30 miles) from the plant, into a bustling labour hub at the front line of the massive public works project.
In extreme cases, brokers have been known to "buy" workers by paying off their debts. The workers are then forced to work until they pay off their new bosses for sharply reduced wages and under conditions that make it hard for them to speak out against abuses, labour activists and