Why was Chernobyl so much more of a disaster?

[Tom_Scud]

Robert Alvarez disagrees; he thinks there’s a significant danger from the spent nuclear fuel pools:

Along with the struggle to cool the reactors is the potential danger from an inability to cool Fukushima’s spent nuclear fuel pools. They contain very large concentrations of radioactivity, can catch fire, and are in much more vulnerable buildings. The ponds, typically rectangular basins about 40 feet deep, are made of reinforced concrete walls four to five feet thick lined with stainless steel.

The boiling-water reactors at Fukushima – 40-years-old and designed by General Electric – have spent fuel pools several stories above ground adjacent to the top of the reactor. The hydrogen explosion may have blown off the roof covering the pool, as it’s not under containment. The pool requires water circulation to remove decay heat. If this doesn’t happen, the water will evaporate and possibly boil off. If a pool wall or support is compromised, then drainage is a concern. Once the water drops to around 5-6 feet above the assemblies, dose rates could be life-threatening near the reactor building. If significant drainage occurs, after several hours the zirconium cladding around the irradiated uranium could ignite.

Then all bets are off.

On average, spent fuel ponds hold five-to-ten times more long-lived radioactivity than a reactor core. Particularly worrisome is the large amount of cesium-137 in fuel ponds, which contain anywhere from 20 to 50 million curies of this dangerous radioactive isotope. With a half-life of 30 years, cesium-137 gives off highly penetrating radiation and is absorbed in the food chain as if it were potassium.

In comparison, the 1986 Chernobyl accident released about 40 percent of the reactor core’s 6 million curies.

Disagreement/debunking will be gratefully accepted as I really would rather not have this to vaguely worry about. I was pointed to the link by a physicist friend so I don’t think it’s pure hype, but it IS huffington post.

tl;dr potentially 8 times as big as Chernobyl, worst case.

[Whack-a-Mole]

@Sailboat

Well, TMI didn’t stop by itself. The disaster had been exacerbated by human intervention (particularly, by the plant operators developing an incorrect mental model of what was really going on) and, improbably enough TMI was stopped by human intervention – by that rarest kind of human intervention, someone new to the scene who figured out that the mental model was flawed.

Cite

Cite 2

Outside of Hollywood, you can’t always depend on that one guy coming in at the last minute and figuring out the key piece of info. It was one guy who saved TMI, not some fail-safe design.

You can hem and haw all you like.

TMI had a full-on melt down. As I noted half the uranium melted in the first four hours (only determined much later…was not known at the time).

That slag never breached the reactor much less the containment vessel.

Make no mistake. This was a colossal mess for the power plant. That said I am not sure if the operators tried they could make a worse mess. Certainly the reactor was fucked. That thing would never operate again…it was destroyed for all practical purposes.

The current estimate is not so much as one person has died as a result of the TMI accident.

Compare that to coal. Th very worst a Western reactor could do does not hold a candle to the number of people killed from coal burning plants.

[Tom_Scud]

@Tom_Scud

Robert Alvarez disagrees; he thinks there’s a significant danger from the spent nuclear fuel pools:

Disagreement/debunking will be gratefully accepted as I really would rather not have this to vaguely worry about. I was pointed to the link by a physicist friend so I don’t think it’s pure hype, but it IS huffington post.

tl;dr potentially 8 times as big as Chernobyl, worst case.

Apologies, didn’t realize this had been discussed in this thread.