Ok, you are a certified case 
So you say that having working proof that nobody died in conditions where there were no accidents means everything is ok? LOL!
Japan has had several nuclear plant accidents causing deaths prior to this:
January 1981: Four radioactive leaks in Tsuruga palnt. 278 exposed to harmful levels of radiation.
March 1997: Tokaimura uranium treatment plant has a fire that leads to an explosion. 37 exposed to harmful levels of radiation.
November 1999: Tokaimura has an incident through gross negligence killing two workers. Over 600 people are exposed and 320 000 people from the surrounding area are commanded to stay indoors for the next day.
August 2004: Non-radioactive leak kills four and injures seven at Mihama plant.
July 2007: Worlds largest nuclear plant, Kashiwazaki-Kariwa, suffers damage at 6,8 richter quake. Radioactive leak to the sea. Repairs last untill 2010.
Not one single fatal dose in your examples. Here's one for ya, 28 people died of acute radiation poisoning at Chernonbyl. And around 4,000 may be at risk for fatal cancers. My source? A forum made up of the UN, IAEA, World Bank, WHO, and various governments.
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Trying to stay on topic, Chernobyl was a non nuclear explosion, much like the explosion in Japan. However, lacking a containment building, the explosion caused nuclear material to be spread over a large distance. The plant in Japan is a GE design, most likely very similar to many of the plants in the U.S. They have containment domes that serve the purpose of containing any sort of problem with the reactor. Even in the event of a meltdown, the reactor can be destroyed, and the containment building will prevent a large release of radiation.
If a meltdown does, or has occurred, the fuel will melt, burning through the reactor vessel. It will burn itself down through the building, and possibly into the ground. There will be no nuclear explosion in a meltdown.
At Three Mile Island, the fuel acted much like lava, it cooled at the outer edges of the flow, and sealed itself off.
As long as a secondary explosion does not occur, and the containment building does not fail, there will not be a release of contamination from the reactor.
