I think, three mile island is compared to Fukushima because it has the same technical problem, the failing cooling system for the afterwarmth in the reactors and how the responseble officials tried to handle the situation. Other accidents had other causes.

Fukushima shows what destructive potential  was lying in three mile island accident, what did not happen, the hydrogen detonations were avoided through pumping down the oxygene.
But I agree it is not the same, Fukushima is Three Mile Islands possible worst case multiplied with six  and not the same. The situation is Japan is unique with the earthquake and following tsunami. It is undescribably bad.

In addition, in TMI was not used plutonium beside uran. A heavy metall, what is in generel toxic, radioctive or not. It attach  every part of the body and 40 nanogramm are enough to cause a type of cancer. It is dangerous, if it is inhaled or ingested.

To  compare to Chernobyl it is difficult, because the worst case of Fukushima happily did not happen. And I still hope, it can be turned into in way good. The situation is pretty serious and even stepped today to bad after some positve developments at weekend, but a further detonation can release so much radioation, that noone can repair the cooling system again, the plant is then completly out reach. Every reactor will be left on its own and a core meltdown is determined and go in the ground. It is not only one. There a six.

The radioactive material was spite highly in the air in chernobyl and contaminated great parts of Europe and Asia, and for days it was not possible to blow out the burning graphite moderator.

Fukushima's radioation will be more regional, because of the leakage in the containment, so it will stay round the reactor and will depend on the direction of the wind. In worst case the nuke cloud will be blown for example to Tokio and not to the ocean. A Million city. Ukraine was not so populous as Japan.

But in both cases people had died and will die, and not in a small number. So there is not a difference. This technology is dangerous and has it problems in the engeeniering. Little damages, like fatige and wearout so small to be overseen become more with every year you use the power plant, and the chance arise of a maximum credible accident with this, because they will be figured out in a serious incident or accident. Savety standards are not good enough proved by a lot of studies in regard to terror acts and the buildings or reactor containment will be destroyed by an air crash or an earthquake. The consequence is to burn again human life to keep away the worst case and can impact the children of my children is for me personally a too high price and more than one reason to get rid of this. If this labels me as anti nuke radical, I can live it.

..."meltdown" is almost never used by actual nuclear engineers or physicists because it's such a vague term...
I would not say, this is accurate, have a look here.

Luna