I am reading the chart as 300 Millisieverts, its non linear. That is more than a nuclear worker can be exposed to in a year but not enough to cause radiation sickness even as a single dose. You would be monitored as you would have an increased risk of cancer but over 500 days the dosage is high but not in itself dangerous.
Two workers at Fuckushima were exposed to 180 mSv as a single dose and are in good health.
400mSv for radiation sickness, 4-8 seiverts is a fatal dose.
Not seen the film yet but did enjoy the book even if it felt a bit Robinson Crusoe in space at times.
If you believe what japanese media tells you about the health and safety of their workers, I don't know if there is any point arguing on nuclear topics. It's the biggest can of worms since Chernobyl, and 3x times worse than it, with people being hired by the yakuza to work on the plant, without being officially monitored since they're contractors of contractors of contractors, subsidaries whose number of workers is totally unknown, ect.
More info on mars radiations here. http://www.mars-one.com/faq/health-and-ethics/how-much-radiation-will-the-settlers-be-exposed-to
They'd get exposed to so much radiations, there is no point
in sleeping outside just to accumulate more risky amounts! How much mSv would it be, spending 10h a day, everyday for 210 days? Plus the back and forth trip to earth, and the fact that he does hope to not get a cancer once he gets home.
Why do it? He doesn't have enough physical oxygen canisters to even do it anyway. His rover has an oxygenator that provides endless supplies of it.
The way he turned it into a hippy van was a great source of ingenuity and comic relief as well as the only scientifically correct way to do it.
Maybe you're right on pointing at Fukushima, maybe these days it's better if the public forgets about radiations, so they plain and simple won't mention them.