The population exposure from radiation from Fukushima will likely cause some hundreds of cancers. These will not be statistically detectable, but that doesn't mean they won't exist and that policy cannot take their plausible existence into account.
Any sources for this estimation? I've read nothing even remotely close to that prediction. At its peak, people in Fukushima city were only receiving ~0.06 mSv/day of radiation. This only lasted a couple of days. The vast majority of people didn't even face that since they were evacuated.
In contrast, a transatlantic flight results in about 0.1 mSv of radiation. Someone getting a single abdomen x-ray would get over 0.2 mSv.
