There were NOT "millions of dead" at Chernobyl. There were 33 men killed by radiation fighting the burning graphite pile. Subsequently another six men died. Ten more died from various accidents including the crew of a crashed helicopter. There are NOT "millions of dead".
Since then, although so-called "experts" confidently predicted another 700,000 would die from the radioactives, the difference between death rates of those living in the exclusion zone and the rest of the country is virtually indistinguishable. Chernobyl supplied the first large data sample that cast doubts upon the "Linear No Threshold" model of radioactive casualties.
Caldicott makes statements without supporting data. That is why she has zero credibility.
As for Three Mile Island, the only radiation released was a bubble of mildly radioactive hydrogen (i.e. hydrogen containing the Tritium isotope in low concentration) vented from the pressure vessel when it was filled with water after the core melted. The containment vessel worked as designed, the gas should have been vented into storage, but was not due to human error. Zero radiation casualties. Ditto for Fukushima Dai-Ichi.
These are facts. We know the names of those killed at Chernobyl. Just as we know the names of the two TEPCO employees who walked through the contaminated water and lost three days of work due to radiation burns on the feet, and the one elderly man who was killed when he fell from the top of the newly constructed contaminated water storage tank at Fukushima Dai-ichi.
The statistics don't lie. Nuclear power is safer than any other form of power generation.
http://nextbigfuture.com/2011/03/deaths-per-twh-by-energy-source.html