Interesting and disturbing article in the New York Times today.
Japan has a two-tier labor system.
Employees of major companies are well-paid, are almost guaranteed long term employment, and mostly are highly educated, many specialists. They make up only about 20 per cent of the labor used by companies such as TEPCO.
The other 80 percent or workers are hired on contract, no job security, and none of the protection and perks of the top 20 percent.

"Day Laborers Braved Radiation for a Temporary Job"

"........thousands of untrained, itinerant, temporary laborers who handle the bulk of the dangerous work at nuclear power plants here (Japan) and in other countries, lured by the higher wages offered for working with radiation. Collectively, these contractors were exposed to levels of radiation about 16 times as high as the levels faced by Tokyo Electric Power Co. employees last year, according to Japan's Nuclear and Industrial Safety Agency, which regulates the industry. These workers remain vital to efforts to contain the nuclear crisis at the Fukushima nuclear plants."
"They are emblematic of Japan's two-tiered work force, with an elite class of highly paid employees at top companies and a subclass of laborers who work for less pay, have less job security and receive fewer benefits. Such labor practices have both endangered the health of these workers and undermined safety at Japan's 55 nuclear reactor, critics charge."
"Of roughly 83,000 workers at Japan's 18 commercial nuclear power plants, 88 percent were contract workers in the year that ended in March, 2010, the nuclear agency said. At the Fukushima Daiichi plant, 89 percent of the 10,303 workers during that period were contractors."
Interviews paint a bleak picture of workers battling heat cleaning off radiation from reactor drywells and spent-fuel pools using mops and rags, clearing the way for TEPCO employees and inspectors, and filling drums with contaminated waste.
Wages fluctuate. One was paid $350 for two hours work at Fukushima and others speak of wages up to $1000/day. TEPCO refuses to discuss the contract workers and how many have been exposed to radiation.

There are attempts to form unions. The company attitudes are reinforced by those of the average Japanese, where a seldom-discussed class system exists. Moreover, foreigners such as the Koreans and southeast Asians are subjected to discrimination.