Tokyo (CNN) -- They sleep anywhere they can find open space -- in conference rooms, corridors, even stairwells. They have one blanket, no pillows and a leaded mat intended to keep radiation at bay.
They eat only two meals each day -- a carefully rationed breakfast of 30 crackers and vegetable juice and for dinner, a ready-to-eat meal or something out of a can. They clean themselves with wet wipes, since the supply of fresh water is short.
These are the grueling living conditions for the workers inside Japan's crippled Fukushima Daiichi nuclear power plant. They've been hailed as heroes risking their lives by braving high levels of radiation as they work to avert a nuclear meltdown.
But until now, the outside world has known little about the workers' routine.
Tuesday, safety inspector Kazuma Yokota, who spent five days at the plant last week, spoke with CNN about the plight of the 400 workers staying in a building within 1 kilometer (.6 miles) of Reactor No. 1. Japanese officials ordered mandatory evacuations for everyone else within 20 (12.4 miles) kilometers of the plant.
The workers look tired, Yokota said. They are furiously connecting electrical cables, repairing instrument panels and pumping radioactive water out.
They work with the burden of their own personal tragedies always weighing heavy.
"My parents were washed away by the tsunami, and I still don't know where they are," one worker wrote in an e-mail that was verified as authentic by a spokesman for the Tokyo Electric Power Co., which runs the Fukushima plant.
"Crying is useless," said another e-mail. "If we're in hell now, all we can do is crawl up towards heaven.'
But they are doing it all with the kind of determination required in a task with such high stakes. There's no room for plummeting morale and the workers are not showing any signs of spirits flagging, Yokota said.
However upbeat the workers are, there's no denying the conditions are beyond difficult.