Where are they? In the scaremongering imagination of pop writers and lobbying scientists. Last time I checked there was a <3% leukaemia bump after 'the worst nuclear disaster in the world'.
Most of the really nasty stuff (high-level actinide waste) is highly radioactive because it decays so quickly. After the reactor is shut down and the fuel rods are removed, all that stuff is gone, whereas breach of a critical reactor results in the release of that stuff. The byproducts of a fuel fire is stuff like radioiodine and radiocaesium - it's not healthy by any means, if ingested it will elevate the risk of cancer over the long term, but it's not instadeath like actinide waste.
"What is expected to happen in Fukushima" is nothing like what happened to Chernobyl. A couple years later people are moving back, and it's perfectly safe to do so after some minimal decontamination efforts.
Rates were 1.2 times higher after the accident compared to the pre-accident period among the population living in territories with a level of radioactive pollution exceeding 555 kBq per m2
Between 1986 and 1996 a total of 21 cases of leukaemia were observed in Zhitomir occurring among children born during 1986. A total of eight cases were observed in the largely uncontaminated Poltava region.
It's a conservative model, and thus it tends to get used out of an abundance of caution, but it's hard to quantify low-dose effects accurately. Since we're all exposed to a fair bit of radiation naturally, low doses don't represent much change in total radiation exposure.
Average dosage to the public in the affected countries was about 9 millisieverts [1]. A CT scan is about 10 mSv. The average natural exposure is about 2.4 mSv per year in America, but in some places with high radon levels exposure can be up to 7 mSv/year. It's difficult to reach significance with small changes like that.
[1] http://nuclearsafety.gc.ca/eng/resources/health/health-effec...
http://www.nature.com/news/researchers-pin-down-risks-of-low...