From what I can gather, the chernobyl release is most easily discussed in terms of the percentage of the core that was ejected into the environment. I have read the total activity in the core was approx. 9 billion curies, and that estimates of the total release range from 50 million curies all the way up to all 9 billion curies. Lets assume a 30% release, so roughly 3 billion curies. I also read the total core inventory of I-131 was around 80 million curies. Applying 30% to this gives me 24 million curies of I-131 released. Recently it's been reported that Fukushima has released 2.4 million curies of Iodine, and this has been called roughly 10% of the cherbobyl iodine release (the basis for my 30% assumption above) The same article indicated the Fukushima Cs-137 release to be one seventh the chernobyl amount... This suggests that 3% of "a core inventory" of these radionuclides has escaped into the environment in Japan. Divide by 4 reactors and we get the better part of 1% of each core, or perhaps 3% of one core that may be the main contributer With chernobyl there is no question about how 30% of the inventory of a given radionuclide in the core would escape, but I don't see how even 1% to 3% would have gotten out in Japan. As far as I know, only water and steam that have touched fuel have gotten out, so is it possible that this high of a percentage of these isotopes has been carried out by these methods? In contrast, three mile island, in which gas that was in contact with fuel was released resulted in a comparatively trivial 20 curies or less of I-131 escaping. Can anyone share thoughts on this?