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Comment Re:Please Mod up ... Thorium, the New Green (Score 1) 347

You'd probably want the more recent SUPER PRISM design (optimized for betterness; I think it's fewer larger cores for increased efficiency, along with updated calculations of various sorts)... Though that gimmicky name probably doesn't help in convincing people... Too bad we largely stopped doing research on the PRISM based designs in the 90s.

And I suspect thorium/PRISM/etc. have a major hurdle in economics. The US's current fleet of reactors has a ~91% capacity factor (aka fraction of max electricity/year that we're getting). The capacity factor is highly dependent on highly optimized materials science from the past decades. You don't have that for different fuel/coolant setups. Good luck convincing the power company to build the reactor that's going to have 70% capacity factor instead of one with >90%.

Comment Re:This one is pretty easy to solve (Score 1) 105

In my case, I think I'm safe...

I buy some ebooks from B&N. I then break the DRM with good ole Python, and toss the epub files onto my iPod Touch to be read in Stanza. Granted, Stanza was bought by Amazon a few years ago, but no one's forcing me to install any hypothetical updates to the app.*

*Actually there was an update in November to make stanza work with iPads, or something. This resulted in Stanza not working on iOS 4. But that's what jailbreak+Cydia+Installus is for...

Comment Re:But so could anything (Score 4, Informative) 204

Afaik Chinese are mostly copying Russian tech in this regard, just like they do with weapons.

Going by Wiki, this is incorrect.
http://en.wikipedia.org/wiki/List_of_nuclear_reactors#China
They've got a bunch under construction that use French tech from the 90s (CPR-1000), and then they have the AP1000 and EPR which are American and European, respectively. Finally a trio of CNP-600 which I'm not sure what they are... So definitely not Russian tech.

Thanks for piquing my curiosity, though :)

Comment Re:because we learned nothing from Fukushima (Score 1) 596

2. The day before the Fukushima accident, the NRC granted a 20 year extension to the US Vermont Yankee plant of the exact same design

This decade is going to see a lot of nuclear plants, that built during the 70s, reaching their designed end of life.

Other issues aside... Vermont doesn't have history of tsunamis + earthquakes.

Comment Re:because we learned nothing from Fukushima (Score 1) 596

The problematic welds I were referring are on the pressure vessel, NOT the containment vessel

As for the containment vessel, the air is not corrosive (any more than regular air) unless you have an accident with the pressure vessel. Even on the timescale of Fukushima, I'm pretty sure corrosion won't be a problem before we have such a facility under control.

It's an improvement over a reinforced concrete containment vessel - it can handle about 2.5 times the internal pressure safely.

Is going to steel containment from reinforced concrete (that doesn't handle pressure as well as steel) a step backwards in your opinion?

I will admit that I thought there was a larger gap between the outer building and the steel containment than this picture indicates.

Comment Re:because we learned nothing from Fukushima (Score 3, Interesting) 596

I'm pretty sure there are no (commercial) graphite moderated reactors in the US. (Wandering slightly from that point: I'm also reasonably happy to leave policing other countries' nuclear policy to IAEA rather than the US...) So I'm not sure that's a great example.

I'm not clear on what the bargain basement containment is that you refer to. But I have my own understanding of the changes, which I'll share... From what I've heard/read/learned, past light water reactors in the US use used a single containment vessel: steel reinforced concrete, which is also the reactor building. Newer ones have a solid steel containment vessel AND a concrete reactor building (with less steel reinforcement maybe?.

Why this is better/adequate? Steel is much better as a secondary pressure vessel (think Fukushima hydrogen pressure -> explosion). Steel also conducts heat much better than concrete, so you get heat out of the containment without transferring mass out of containment. Then you drip water on the outside of steel containment to remove the decay heat building up inside, and this also controls the pressure, too. The concrete reactor building is your plane shield.

That said, manufacturing that giant steel vessel is an added cost that other reactors didn't have. They also made the actual pressure vessel more expensive to fabricate by getting rid of some of the weld seams. (Said seams end up being the most likely candidate of problems after 40 years of reactor operation, though such failure has not occurred in the US... Fukushima maybe? I don't think we know yet.)

(I am a nuclear engineering grad student, but keep in mind curriculum doesn't spend that much time on actual reactor containment design... so I'm not an expert, per se)

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As far as the laws of mathematics refer to reality, they are not certain, and as far as they are certain, they do not refer to reality. -- Albert Einstein

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