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Thorium Instead Of Uranium: Solution To Our Energy Woes?

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Re: Thorium Instead Of Uranium: Solution To Our Energy Woes?

#61

Post by uvdiv »

terra_t wrote: post #51
uvdiv wrote: post #38

Earlier quoted context omitted.

> if we reprocessed all spent fuel in the U.S. today, we'd have enough Pu to power about 33 MWe worth of breeders, about 1/3 of the current fleet. That should be "GWe" not "MWe". Also, I dispute your choice of statistic. Why not show what happens if you start fast breeders on mined uranium, just like LWRs?

Sorry I missed a factor of 1000. Fast breeders on mined uranium have the same problem as plutonium breeders... Except you can breed plutonium faster (but less efficiently) in LWRs!

I mean, it's an odd statistic. You can use U-235 directly, or you can burn it in an LWR, getting back just 1/5th its equivalent in Pu-239, and use that. If you're trying to maximize fissile input for fast breeders, LWR spent fuel isn't an efficient way.

And moreover, with mined uranium there's no limit to your rate of expansion other than mining. You don't have to sit and wait for your atoms to reproduce (doubling time 20-40 years), when you can just dig up new ones.

Some back of the envelope numbers:

Assuming 3% enriched fuel burned to 40 GWd/ton, and 33% thermodynamic efficiency, the US nuclear fleet (~100 GWe) consumes around 100 tons/year of U-235 in fuel. At about 10 kg/MWe fissile inventory, just 10 years' of present US uranium consumption would be enough (1,000 tons) to start up a 100 GWe fleet of fast breeders -- same as the current LWR fleet.

I found a table of fissile inventories here:

http://nuclear.inl.gov/deliverables/docs/msr_deliverable_doe...

Re: Thorium Instead Of Uranium: Solution To Our Energy Woes?

#62

Post by warfangle »

whyenot wrote: post #56

I'm all for thorium and nuclear energy, BUT only if we in the US stop with the NIMBY-ing and find a permanent storage location for nuclear waste.

No need for a 'permanent storage solution' for thorium waste. What little waste there is decays to safe levels in less half a century.

Re: Thorium Instead Of Uranium: Solution To Our Energy Woes?

#63

Post by mkn »

henrikschroder wrote: post #28
DanielBMarkham wrote: post #21

I'm a big fan of Thorium, but I'm also a big fan of nuclear in general. It just makes sense. In fact, this is a lot like the issue of not building any oil refineries in the United States since the 1970s. While I'm sure there are good reasons for our lack of needed nuke plants, at the end of the day it looks like the system has let us all down. I hate to sound like old cranky guy again, but frack, if you really wanted…

Nuclear power plants can't replace oil- or coal-powered plants, because nuclear plants can't adjust output over the day to fit actual usage. Nuclear power plants are great for providing the baseline power production, but you need something adjustable to handle the morning and evening peaks, like oil or coal or wind or hydro or really big batteries. So no, you can't do the math for how many nuclear plants you would ne…

You're thinking of solid-fuel uranium reactors.

Actually, thorium reactors have a natural load-following capability due to their negative thermal coefficient of reactivity. You suck power out of them too fast, they cool, get denser, and the reaction rate increases, increasing power output.

In addition, shutting down a liquid salt reactor is literally a matter of pulling, actually melting, a plug. Simply overheat the core, melting the freeze plug, and the fuel falls into a subcritically shaped catchment tray. Reheat and reload and the reactor is up again. They're very easy to start and stop.

There's a wealth of information on the Net about these guys. I hope they get built!

Re: Thorium Instead Of Uranium: Solution To Our Energy Woes?

#64

Post by fhars »

pjscott wrote: post #34
henrikschroder wrote: post #28

Earlier quoted context omitted.

Nuclear power plants can't replace oil- or coal-powered plants, because nuclear plants can't adjust output over the day to fit actual usage. Nuclear power plants are great for providing the baseline power production, but you need something adjustable to handle the morning and evening peaks, like oil or coal or wind or hydro or really big batteries. So no, you can't do the math for how many nuclear plants you would ne…

France is using some of their nuclear plants to provide peak load, and they adjust the power output of most of their plants over the day to better fit the actual usage. Their reactors are not ideal for this; there are better ways to design nuclear plants for load-following. But it can certainly be done. Alternately, you could make enough nuclear capacity to provide your peak power levels all the time , and dump exces…

And they buy massive amounts of coal produced electric energy from germany during peak load times in winter.

Re: Thorium Instead Of Uranium: Solution To Our Energy Woes?

#65

Post by tbrownaw »

sethg wrote: post #41
DanielBMarkham wrote: post #21

I'm a big fan of Thorium, but I'm also a big fan of nuclear in general. It just makes sense. In fact, this is a lot like the issue of not building any oil refineries in the United States since the 1970s. While I'm sure there are good reasons for our lack of needed nuke plants, at the end of the day it looks like the system has let us all down. I hate to sound like old cranky guy again, but frack, if you really wanted…

The US government already provides massive incentives for nuclear power, but even with those incentives, nobody is building. Maybe the American nuclear industry just has such an awful record of cost overruns that investors don’t want to give them any more rope. But if the Indians can run their nuclear industry in a more competent fashion, good for them.

> American nuclear industry just has such an awful record of cost overruns

Due primarily to NIMBY lawsuits, IIRC. Nuclear is technically easyish, but misinformed protesters make it socially/legally messy.

Re: Thorium Instead Of Uranium: Solution To Our Energy Woes?

#66

Post by rubashov »

pjscott wrote: post #47
sethg wrote: post #41

Earlier quoted context omitted.

The US government already provides massive incentives for nuclear power, but even with those incentives, nobody is building. Maybe the American nuclear industry just has such an awful record of cost overruns that investors don’t want to give them any more rope. But if the Indians can run their nuclear industry in a more competent fashion, good for them.

The US government has a horrendous nuclear regulatory regime. If anything, they're anti-subsidizing.

Without the government's liability coverage for nuclear plants, none would ever be built at all. A nuclear plant is simply un-insurable.

To all those people who insist nuclear power is very safe: no private insurance company has ever concluded the risks are sufficiently quantifiable to offer insurance.

Re: Thorium Instead Of Uranium: Solution To Our Energy Woes?

#67

Post by gamble »

tbrownaw wrote: post #65
sethg wrote: post #41

Earlier quoted context omitted.

The US government already provides massive incentives for nuclear power, but even with those incentives, nobody is building. Maybe the American nuclear industry just has such an awful record of cost overruns that investors don’t want to give them any more rope. But if the Indians can run their nuclear industry in a more competent fashion, good for them.

> American nuclear industry just has such an awful record of cost overruns Due primarily to NIMBY lawsuits, IIRC. Nuclear is technically easyish, but misinformed protesters make it socially/legally messy.

> Nuclear is technically easyish

Not the way it's been done in the US. Every plant was essentially a one-off design, with all the risks you'd expect from a multi-billion dollar construction project with significant R&D aspects. The industry is trying to standardize on replicable reactor designs, but it's not a cakewalk. Even the French have had a lot of difficulty producing a standard reactor, and few countries have invested as much in nuclear as they have.

Re: Thorium Instead Of Uranium: Solution To Our Energy Woes?

#68

Post by pjscott »

gamble wrote: post #67
tbrownaw wrote: post #65

Earlier quoted context omitted.

> American nuclear industry just has such an awful record of cost overruns Due primarily to NIMBY lawsuits, IIRC. Nuclear is technically easyish, but misinformed protesters make it socially/legally messy.

> Nuclear is technically easyish Not the way it's been done in the US. Every plant was essentially a one-off design, with all the risks you'd expect from a multi-billion dollar construction project with significant R&D aspects. The industry is trying to standardize on replicable reactor designs, but it's not a cakewalk. Even the French have had a lot of difficulty producing a standard reactor, and few countries have…

This is why I'm optimistic about smaller reactors like the B&W mPower reactor, or China's HTR-PM pebble bed reactors. They're meant to be cranked out in bulk, identically, and shipped out to wherever the site is.

The AP1000 also looks like a pretty impressive attempt at standardization, since it comes mostly in the form of factory-produced modules that get assembled on-site.

Re: Thorium Instead Of Uranium: Solution To Our Energy Woes?

#69

Post by ScotterC »

AndrewHampton wrote: post #17
ScotterC wrote: post #11

Earlier quoted context omitted.

You can find it pretty much anywhere actually. It's a by-product of many mining processes and India has literal beaches of it.

I believe magamiako is referring to areas in World of Warcraft where thorium can be found.

Haha. That went completely over my head. Woosh!

Re: Thorium Instead Of Uranium: Solution To Our Energy Woes?

#70

Post by ScotterC »

sethg wrote: post #41
DanielBMarkham wrote: post #21

I'm a big fan of Thorium, but I'm also a big fan of nuclear in general. It just makes sense. In fact, this is a lot like the issue of not building any oil refineries in the United States since the 1970s. While I'm sure there are good reasons for our lack of needed nuke plants, at the end of the day it looks like the system has let us all down. I hate to sound like old cranky guy again, but frack, if you really wanted…

The US government already provides massive incentives for nuclear power, but even with those incentives, nobody is building. Maybe the American nuclear industry just has such an awful record of cost overruns that investors don’t want to give them any more rope. But if the Indians can run their nuclear industry in a more competent fashion, good for them.

The current energy industry is so over regulated that it completely stifles innovation. It's worse then Taggart Transcontinental
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