[bvw]

TMI a 5? More like a 4, by their own metrics. The Japanese reactor is still only a 5 on their scale. It might become a 6. But here is the one '6' according to Wikipedia entry:

Kyshtym disaster at Mayak, Soviet Union, 29 September 1957. A failed cooling system at a military nuclear waste reprocessing facility caused a steam explosion that released 70–80 tons of highly radioactive material into the environment.

IMO the Japanese reactor park disaster will end up releasing one tenth of that or less. I would guess the release so far -- of radioactive material -- is under a ton. Since the NGO claims each level is 10x worse, we are still at a 5.

[1010RD]

Potentially a 5, we’re still bet. a 4 and a 5 IMO.

The International Atomic Energy Agency said radiation dose rates of up to 400 millisievert (mSv) per hour had been reported at the Fukushima plant site immediately following one of the explosions...

Today the IAEA said, “observations indicate that the level of radioactivity has been decreasing at the site.

From here: http://abcnews.go.com/International/japan-earthquake-radiation-leaking-fukushima-reactors-containment-vessel/story?id=13136890

3 minutes ago.

[Dan Nunn]

TMI a 5? More like a 4, by their own metrics.

Except the International Atomic Energy Agency disagrees with you, saying:

"One of the key considerations in developing the criteria for the INES scale rating was to ensure that the significance level of less severe and more localized events were clearly separated from this severe accident. Thus the 1979 accident at the Three Mile Island nuclear power plant is rated at Level 5 on INES, while an event resulting in a single death from radiation is rated at Level 4."