Thank you, that clears things up. So the possible (or likely) scenario at Fukushima is that the fuel rods will overheat to complete meltdown and workers will have to abandon the area until radiation levels subside enough to clean up. Is that about right? My concern has been that the inner containment structures will fail with the increased steam pressure, releasing radioactive material and steam. It seemed like that was a concern to scientists and media as well.

That's just the reactor. However, what we're worried about are the coolant pools containing the spent fuel. Once exposed to air, the fuel rods could fall apart, with the uranium pellets falling into a pile that could go critical. What's better (or worse) about this scenario compared to Chernobyl?

@Tom
You are right that the spent fuel rods are probably more concerning right now. However you can to consider that the reason the spent fuel rods are the problem is that if that situation gets out of control the entire complex must be abandoned which means the fission reactors would melt down. I was writing above about the actual fission reactors melting down.

Most things in this scenario are better than Chernobyl. The risk of the spent fuel rods turning into a criticality is "none zero" which means it could potentially happen but is unlikely.

If it appears a criticality would happen with the spent fuel rods this can be prevented with human intervention. You could dump boron, graphite, water or other neutron absorbing material on the melted spent fuel cells. Boron is the better material because it is not flammable like graphite.

Speaking of graphite, Chernobyl used graphite in the reactor which caused the fires to be much worse than what Fukushima could ever be.

Fukushima is not already worse than Chernobyl. Chernobyl released a significant amount of radiation into the atmosphere. That has not happened yet with Fukushima and it might not happen.

The situation in Japan is concerning but it is in no way worse than Chernobyl. Please take your hysteria elsewhere and stick to the facts here.

Packateer-

I agree with you that Ritter is overstating the current situation. However, I want to clear something up: are you, in any way, being paid to provide these answers? Do you work in, or for, the nuclear industry, a public relations firm, a lobbying organization, or government agency?

I am not paid in any way to give these answers. I also don't have any friends or family employed in the nuclear industry. I am just a nerd who has had an interest in particle physics since I was a child. I am a best described as a hobbyist, not a professional.

I do however work in computer network security and part of my professional life involves explaining risks and contingencies to people. Anyone in the security industry will tell you that humans are very poor at understanding statistics and risks. I sympathize for everyone who is freaking out, it is only human, but their opinions need to be brought to light immediately or they can spread panic and misinformation.

Sometimes, sometimes, I wish we as a people would only listen to experts. Because when you have rabble-rousers like this asshole who talks out of his ass about how this is the worst disaster ever... well it can cause people to die due to panic related hysteria.

Thank you Gregory Ritter, for being an asshole.