Fine. I am not a nuclear scientist. But I do know that a lot of the people saying this is not a serious problem will look awfully dumb if they are wrong. I trust they know what they are talking about but if this does become a catastrophe they will have lost a boatload of credibility ... Including many on these threads.
Dr. Robert Zubrin is the president of Pioneer Astronautics and the author of Energy Victory: Winning the War on Terror by Breaking Free of Oil. He holds a Ph.D. in nuclear engineering.

You look awfully dumb right now. There is ZERO risk to the United States. NONE. Climb out of your backyard fallout shelter, put away your Potassium Iodide tablets.
There's some potential risk to Japanese within the evacuation zone in the WORST CASE if the nuclear fuel melts through all containment. We're not there.
Yesterday's media panic-inducing 400 mSv radiation detection at the plant was less than half that required to cause nausea.
Serious problem? Let's see... 10,000 are MISSING or DEAD. Two-hundred billion in infrastructure is lost. 350,000 made homeless are facing FREEZING temperatures this week and starvation. Floods invariably bring risk of disease, refinery fires release toxins. Anyone care? Hello? Anyone?
Of course not! That's boring!
Let's stir up a Chicken Little PANIC over the continuing battle to cool reactors, let's menace the world with fear of radiation holocaust! It's NUCLEAR!
How many have been killed by the nuclear plant problem in Japan? None. I pray it stays that way but those engaged in the battle, like all first responders, are at risk. This isn't a one day battle. Expect it to take two weeks.