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Comment: Re:Reprocessing? (Score 1) 241

by Rising Ape (#47802531) Attached to: Feds Want Nuclear Waste Train, But Don't Know Where It Would Go

The fact that material with less than 2% fissile content can't go critical on fast neutrons is easily calculated by looking at the well measured fission and absorption cross-sections for U-238, U-235 and Pu-239. There's a *reason* why fast reactors use fuel with fissile content of 15%-20%, despite the higher cost of doing so.

Everything that happened at Fukushima can be explained by loss of AC power -> loss of coolant -> decay heat driven meltdown -> containment failure due to containment pressure & temperature beyond design limits. The decay heat is quite large - tens of megawatts for hours to days after shutdown. There's absolutely no need to invoke criticality to explain what happened, and absolutely no evidence that there was any such criticality. And a detector at the gate certainly couldn't provide any such evidence as the cores were and are inside enough shielding to block the neutrons that result from full power operation. You know, to stop the workers from getting radiation poisoning from normal operations. Any neutron pulse large enough to be detected there would have had to come from a fission reaction large enough to pretty much level the entire site and kill everyone nearby.

And before you mention the spent fuel pools again, the fuel in those has been inspected and found to be intact. So no meltdown there.

The weird thing is that my original post was explaining why a particular nuclear solution *wasn't* a quick and easy answer. I'd have thought that'd be the kind of thing you'd agree with.

Comment: Re:Reprocessing? (Score 1) 241

by Rising Ape (#47802265) Attached to: Feds Want Nuclear Waste Train, But Don't Know Where It Would Go

What sort of neutrons do you suppose are involved in a meltdown?

What happens in a meltdown is irrelevant to my original post, which was referring to use of spent LWR fuel in a fast reactor and had nothing to do with meltdowns of any kind. Stop moving the goalposts.

But since you ask - in a meltdown like Fukushima? No neutrons. It was subcritical and the meltdown was caused by decay heat, as was Three Mile Island. Chernobyl was driven by thermal neutrons - it would have been subcritical on fast neutrons alone.

As you would know if you put a fraction of the effort into researching a subject as you do on talking about it.

Comment: Re:Reprocessing? (Score 1) 241

by Rising Ape (#47801073) Attached to: Feds Want Nuclear Waste Train, But Don't Know Where It Would Go

No mistake. I said "You can't just dump spent LWR fuel into a fast reactor - the concentration of fissile material is far too low for it to go critical.". Which is true, without a moderator even fresh LWR fuel won't go critical, let alone spent fuel.

Do you even bother reading comments or just shoot off your anti-nuclear points as often and as fast as you can?

Comment: Re:Reprocessing? (Score 3, Informative) 241

by Rising Ape (#47796485) Attached to: Feds Want Nuclear Waste Train, But Don't Know Where It Would Go

You can't just dump spent LWR fuel into a fast reactor - the concentration of fissile material is far too low for it to go critical.

Reprocessing's been done, but it's quite messy and there's no demand for the recovered fuel. Making MOX is much more difficult and expensive than making standard uranium fuel. It's cheaper, easier and probably safer to just store the spent fuel in dry casks until a suitable disposal site is found. Fortunately, those casks last a long time.

Comment: Re:Public cynicism about fusion (Score 1) 147

by Rising Ape (#47751377) Attached to: Princeton Nuclear Fusion Reactor Will Run Again

If I were king of the world, I'd fund solar heavily because it can do good NOW.

We are funding solar heavily. Something like 37 GW of solar was installed worldwide last year. That's tens of billions spent in one year, more than an order of magnitude more than is spent on fusion development. And that's just for one type of renewable energy. R&D is cheap, deployment is expensive - so it makes sense to fund research into lots of different things in case one of them pays off.

Now, I think that fusion is probably going to be just too tricky - but I might be wrong, and there are helpful spinoffs in superconductor technology, etc.

Comment: Re: American car companies... (Score 1) 426

I'm from Europe myself (well, Britain), so I know about the kind of models we get. It's not clear what "fault rate" means - does this refer to number of faults discovered at legally required inspections (like the UK MOT)? A simple percentage is a bit vague as it doesn't give any indication of how costly the faults are to fix.

I was basing my original comments partly from the figures from here,as that tries to take into account cost of repairs too.

Comment: Re: American car companies... (Score 1) 426

Do you have a link to those statistics? I'd genuinely like to know, because everything I've seen suggests that the German brands are not as good as Ford for reliability these days. Especially BMW, which may be nice to drive but can have some expensive problems (cooling systems that break after 60k miles, high pressure fuel pumps, diesel engine swirl flaps which can come loose and destroy the entire engine...). The Japnnese brands are typically better than both though.

It's debatable to what extent Ford of Europe can be considered American cars anyway - they have traditionally had completely different models and manufacturing plants.

Comment: Re:not big in UK (Score 3, Informative) 120

by Rising Ape (#47651667) Attached to: Gas Cooled Reactors Shut Down In UK

Especially in this case since Windscale was also gas-cooled.

Air-cooled. Which is indeed a gas, but very different to the CO2-cooled reactors described here. Windscale was an air-cooled, open-loop plutonium production reactor designed in the 1940s. It didn't generate electricity and has very little relation to the later electricity-generating reactors.

Comment: Re:Not unheard of (Score 1) 442

by Rising Ape (#47610593) Attached to: Big Bang Actors To Earn $1M Per Episode

I didn't complain about them, I was making a more general point. Jealousy is indeed not a good reason to stop someone from earning money, but accusations of jealousy are often used to stifle legitimate complaints about wealth distribution in the world. Few people would expect everyone to be paid the same, but having CEOs earning 1000 times an average employee is hardly reasonable either, given that that money only exists thanks to the work of those lower down. It's not jealousy to question that.

Comment: Re:Not unheard of (Score 1) 442

by Rising Ape (#47609783) Attached to: Big Bang Actors To Earn $1M Per Episode

Unequality is not a bad thing - it's natural

Most wealth inequality is far from natural - it's the result of it being easier to get more money when you already have it, thus favouring those from wealthy backgrounds. It's no more natural than the old feudal system, where those who inherited land and titles had the power.

Comment: Re:Nuclear power is in decline (Score 1) 343

Power purchase agreement prices are not the whole story as they ignore the effects of any extra, separate subsidies (such as the federal tax credit for wind). If the PPA was the whole story, why is there such a large variation (factor of 3) in prices for the same year? The nuclear price is an "all-in" levelised cost of electricity (plus an element of profit for EDF) - the relevant comparison is to the equivalent for wind, which your own link shows to be $80 to $100 per MWh. Unless the Energy Information Administration have got it wrong, but I trust them more than the AWEA's carefully selected figures. Would you trust nuclear figures from Areva?

And as I said before, what they can *sell* power for isn't necessarily what it costs to produce. Germany often now has negative wholesale electricity prices - is that because they can genuinely afford to pay people to take it away? No, it's because they get a separate feed in tariff for anything produced. There are many factors determining the sale price, which is why I'm trying to compare based on the actual costs of installation. And that shows nowhere near as rosy a picture as you're trying to paint.

With the cost of wind falling, the fairer comparison would be for future wind PPA's where we might see a factor of 12 or 14 rather than seven.

Can I borrow your crystal ball when you've finished with it? Your own link shows that the cost does *not* consistently fall - there's a significant increase from 2000-2008, for example. There's a recent fall since that peak, but if it went up before it can do so again.

Repel them. Repel them. Induce them to relinquish the spheroid. - Indiana University fans' chant for their perennially bad football team

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