But let's review those three meltdowns. Three Mile Island didn't cause a single case of cancer. Chernobyl was a ridiculously unsafe design run with incredible incompetence. The WHO estimates it caused 40,000 cases of cancer and 4,000 deaths from those cancers. That may sound bad, but pollution from coal kills around 30,000 people each year just in the US. Finally, there's Fukushima. It's expected to cause 100-200 premature deaths from cancers. Remember, the cause of that meltdown was an earthquake-tsunami combo that killed almost 20,000 people.
If anything, shutting down nuclear power worsens public health. Demand for electricity isn't going to go down, so we end up burning coal, and coal plants are much worse than nuclear. From http://squid314.livejournal.com/292620.html:
According to the Clean Air Task Force, coal plants kill about thirty thousand people per year in the US through pollution (which causes respiratory disease). There are six hundred coal plants, so that's about 50 deaths per plant. These numbers are much higher - maybe even by an order of magnitude - in Chinese and third-world coal plants, which lack the US' stringent environmental restrictions.
Even in the worst-case scenario, nuclear power still does better than coal:
When you hit a nuclear plant with the fifth largest earthquake ever recorded, then immediately follow that with a twenty foot high tsunami, and then it explodes, it still kills fewer people than an average coal plant does every single year when everything goes perfectly.
There are lots of things that cause long-term harm to the environment: toxic chemicals, heavy metals, and yes, radioisotopes. If we want to enjoy a first-world quality of life, we have to accept some pollution. The least harmful energy source today is nuclear power.