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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?

#31

Post by ColinDabritz »

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…

Can we not solve this problem by storing energy in the longer term?

It's true some 'burst' capacity is important, but can you not get a lot closer to 'average load' than the baseline by using the energy? Pumping water into a reservoir at night, and getting the power back with a small hydro plant during the day comes to mind. We smooth out an even worse problem with wind and solar, which is spiky AND out of sync with demand sometimes. I believe flywheels are used to store energy in the short term sometimes. You did mention 'really big batteries', implying that we would need too many, but we aren't limited to chemical forms of energy storage.

I think this is a solved problem, or at least a fairly solvable problem, and nuke plants can provide not only the 'baseline' but close to the bulk average needs for power. We can decouple the power generation and the need for "something adjustable" and benefit.

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

#32

Post by pjscott »

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.

Incidentally, comments like that are why it's so irritating to try to have discussions of thorium on Reddit. Of the people who post in those threads, a significant fraction are just there to make WoW references.

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

#33

Post by narrator »

GiraffeNecktie wrote: post #4

The short answer is that there are many entrenched interests who are not keen on the idea: Uranium mines, nuclear industry, weapons manufacturers, not to mention the oil, gas and coal lobbies, even the alternative energy suppliers like solar. Thorium would rain on all their parades.

No conspiracy theory necessary. There are only a small number of people who can design and build things of nuclear reactor level complexity from scratch and they mostly work at government labs and for major engineering firms. The government wanted these people to focus their attention on the designs that would be useful for the cold war weapons programs so the thorium reactors just didn't get built.

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

#34

Post by pjscott »

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…

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 excess energy into some energy-hungry industrial process, like aluminum smelting, or synthetic fuel production, or ammonia synthesis.

So yes, you can do the math. It's just that there are a bunch of different ways to do that math, and most of them involve a lot of cleverness, large budgets, careful engineering, and a fair dose of uncertainty.

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

#35

Post by wtallis »

sdurkin wrote: post #23
Retric wrote: post #16

Earlier quoted context omitted.

The real answer is the R&D costs are not worth it because Uranium is still extreamly cheap. The fuel costs for a modern reactor are a small fraction of total cost. Also, fosil fuels a not going to be replaced with wind, solar, fission or fusion any time soon because they are not really portable for anything smaller than a boat.

You're both right. "The real answer is the R&D costs are not worth it because Uranium is still extreamly cheap." This answers why the market won't develop the technology on its own. But the government could still sponsor research as they did with uranium fission. "The short answer is that there are many entrenched interests who are not keen on the idea..." And this answers why the government would never fund it.

As soon as the market has to bear the cost of long-term storage of waste, they'll be interested in thorium.

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

#36

Post by greyfade »

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…

Yes you can.

Liquid-Fluoride Thorium Reactors can be started and stopped without incident, in a few hours. I believe their output can also be adjusted in operation. They're safe and efficient enough to build one into a 40-foot trailer that can be started, stopped, and moved on a moment's notice.

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

#37

Post by henrikschroder »

ColinDabritz wrote: post #31
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…

Can we not solve this problem by storing energy in the longer term? It's true some 'burst' capacity is important, but can you not get a lot closer to 'average load' than the baseline by using the energy? Pumping water into a reservoir at night, and getting the power back with a small hydro plant during the day comes to mind. We smooth out an even worse problem with wind and solar, which is spiky AND out of sync with…

Here's the electricity demand curve for the UK for the last 8 days:

http://www.nationalgrid.com/uk/Electricity/Data/Realtime/Dem...

Electricity demand during the night is about half of what it is during the day. If you were to have nuclear baseline production that covers peak consumption, you would have to find a way to store about 100000MWh of energy that gets produced during the night and then distribute that during the following day, or you would just waste it, somewhere, somehow.

(Disclaimer: Back-of-the-envelope math, I'm assuming the scale on that graph is in MW, it's only for the UK, not the US)

Yes, it's not an impossible problem. Yes, you can even out the peaks by changing behaviour. Yes, you could perhaps figure out a way to store and release that much energy each day.

But my point still stands, replacing fossil-based electricity production with nuclear is not trivial, it's a lot more complicated than summing up the total output of all fossil-based plants and dividing it by the average output of a new nuclear plant as DanielBMarkham argues.

I'm also a big fan of nuclear. Many countries would probably benefit from having their baseline production completely covered by nuclear plants. But how to deal with peak demand of electricity without fossil-based production and in an economically viable way, that is not a solved problem yet.

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

#38

Post by uvdiv »

terra_t wrote: post #19
Retric wrote: post #18

Earlier quoted context omitted.

We have already mined something like 100 years worth of Uranium that is just waiting around to be used in power plants. Or, if the US moved to breeder reactors we could go for something like 1000 years without mining any new uranium.

The trouble with fast breeders is that you need a huge fissile inventory to get one started. A study of the PRISM design, a modern fast breeder that uses integral reprocessing to reduce the inventory of plutonium that's sitting around, not fissioning, indicates that 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. It comes…

> 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?

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

#39

Post by pjscott »

greyfade wrote: post #36
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…

Yes you can. Liquid-Fluoride Thorium Reactors can be started and stopped without incident, in a few hours. I believe their output can also be adjusted in operation. They're safe and efficient enough to build one into a 40-foot trailer that can be started, stopped, and moved on a moment's notice.

My favorite idea for this sort of thing is to put a LFTR on a barge (or, better, in a submarine), using seawater for cooling, and ship them out to any coastal area where they're needed. Build them in factories, assemble them in shipyards where such things are relatively easy, and handle the periodic maintenance and refueling in a centralized location.

Here's where it gets really fun: you can use the waste heat for desalination. There are a lot of places that sit next to a coastline but are short on electricity and fresh water. Russia is trying to make a lot of money from this, using a variant of the reactors they've been using on their nuclear ice-breaker ships.

And if you're using something like a LFTR that's compact enough to fit in a submarine, the water will protect you from hurricanes, earthquakes, aerial attack, and so on. It's a pretty clever scheme. Here's a thread on the Energy From Thorium forums discussing it:

http://energyfromthorium.com/forum/viewtopic.php?f=43&t=...

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

#40

Post by Retric »

olegkikin wrote: post #27
Retric wrote: post #18

Earlier quoted context omitted.

We have already mined something like 100 years worth of Uranium that is just waiting around to be used in power plants. Or, if the US moved to breeder reactors we could go for something like 1000 years without mining any new uranium.

Your 100 and 1000 year assumptions are just silly. You assume energy demands will remain constant, while they are exponential. Just think what will happen if electric cars become popular. We will need a lot of electricity.

Resource usage tends to follow a http://en.wikipedia.org/wiki/Logistic_function not pure exponential growth. Picking a good limit is hard but assuming energy use per person is stays around 5x our current value and US population is limited to 1 billion people 1000 years is an extremely conservative estimate.

Conceder: Between 1980 and 2006, the worldwide annual growth rate was 2%. (http://en.wikipedia.org/wiki/World_energy_resources_and_cons...) If you assume world energy usage will grow 2% per year for the next thousand years you end up with 400,000 times current energy usage however, the sun only supplies the earth with ~10,000 times our current energy use so we would fry the planet with waste heat far before that level. (Think global warming to 800 degrees Fahrenheit.)

PS: In 2009, world energy consumption decreased for the first time in 30 years (-1.1%) or 130Mtoe, as a result of the financial and economic crisis (GDP drop by 0.6% in 2009) so growth is not necessarily even guaranteed.

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