Uranium Is So Last Century — Enter Thorium, the New Green Nuke

[Marcus Bryant]

http://www.wired.com/magazine/2009/12/ff_new_nukes/

[Marcus Bryant]

Named for the Norse god of thunder, thorium is a lustrous silvery-white metal. It’s only slightly radioactive; you could carry a lump of it in your pocket without harm. On the periodic table of elements, it’s found in the bottom row, along with other dense, radioactive substances — including uranium and plutonium — known as actinides.

[Marcus Bryant]

The thick hardbound volume was sitting on a shelf in a colleague’s office when Kirk Sorensen spotted it. A rookie NASA engineer at the Marshall Space Flight Center, Sorensen was researching nuclear-powered propulsion, and the book’s title — Fluid Fuel Reactors — jumped out at him. He picked it up and thumbed through it. Hours later, he was still reading, enchanted by the ideas but struggling with the arcane writing. “I took it home that night, but I didn’t understand all the nuclear terminology,” Sorensen says. He pored over it in the coming months, ultimately deciding that he held in his hands the key to the world’s energy future.

Published in 1958 under the auspices of the Atomic Energy Commission as part of its Atoms for Peace program, Fluid Fuel Reactors is a book only an engineer could love: a dense, 978-page account of research conducted at Oak Ridge National Lab, most of it under former director Alvin Weinberg. What caught Sorensen’s eye was the description of Weinberg’s experiments producing nuclear power with an element called thorium.

[Marcus Bryant]

http://energyfromthorium.com/about/
http://www.economist.com/node/15048703?story_id=15048703

[Marcus Bryant]

http://www.energyfromthorium.com/pdf/

[baseline bum]

No more love for yellowcake? :(

[boutons_deux]

Thorium sounds good, but decades away.

[RuffnReadyOzStyle]

This guy has a nice website devoted to 4th gen nuclear reactors:

http://bravenewclimate.com/integral-fast-reactor-ifr-nuclear-power/

It is the only nuclear the world should invest in - they can't melt down and run on spent fuel rods.

[Wild Cobra]

Seems to me that Thorium would have been used in commercial reactors if it was feasible.

Oh the webs we weave... The Thorium Web...

Problem is, it's half-life is too short. It doesn't give off enough energy. U235 has a half life of 704 million years. U238, which is almost useless for fission has a half life of 4.5 million years. It decays almost 200 times slower, so it just doesn't get hot enough. Now comes Thorium. They have to be talking about 232Th, else it would really be impractical. It's half life is 14 billion years. It decays so slowly, it is harmless to handle. Simply cannot sustain a fission process to create heat.

Now I assume there is some kind of battery that could be made, considering it has an alpha decay. Hard to get any substantial power that way.

OK, the above is my best guess knowing what little I do of fission. I did a little research, found nothing solid to allow thorium to be a usable fission power source. I found this long video, and am watching now. Maybe I'm wrong:

AHs2Ugxo7-8

More videos at World news Thorium (http://wn.com/Thorium)

[LnGrrrR]

WC, I'm always amazed at your willingness to throw out opinions with no research. :D

[Wild Cobra]

WC, I'm always amazed at your willingness to throw out opinions with no research. :D
I'm amazed that people think Thorium can be made viable for fission.

I did some research. Granted, not much, but enough that I simply don't see it happening.

Remember this thread when 20 years from now, we still aren't using thorium for power generation.

[Wild Cobra]

LnGrrrR, do you understand just how next to impossible the theoretical model of the thorium cycle is? You have two neutron bombardment stages of the four cycles. Just how do you direct the neutrons to just the 233U and 232Th when the four isotopes are in the same medium?

[LnGrrrR]

I'm amazed that people think Thorium can be made viable for fission.

I did some research. Granted, not much, but enough that I simply don't see it happening.

Remember this thread when 20 years from now, we still aren't using thorium for power generation.

To be honest, I doubt I'll remember this thread 20 years from now :)

Don't get me wrong, I find it great that you are curious about everything. I just think it's funny that you tend to dismiss things out of hand just on a cursory amount of knowledge.

Where's your world famous skepticism when it comes to the resources you viewed? :D

[LnGrrrR]

LnGrrrR, do you understand just how next to impossible the theoretical model of the thorium cycle is? You have two neutron bombardment stages of the four cycles. Just how do you direct the neutrons to just the 233U and 232Th when the four isotopes are in the same medium?

Sorry WC, I don't claim to be an expert in every subject on this board, that's your niche. :) Is there any field in which you profess ignorance?

[ElNono]

LnGrrrR, do you understand just how next to impossible the theoretical model of the thorium cycle is? You have two neutron bombardment stages of the four cycles. Just how do you direct the neutrons to just the 233U and 232Th when the four isotopes are in the same medium?

Do you realize that there's mixed Thorium-Uranium nuclear reactors already working, right? Did you even bother to read the article?

The cycle is:
- U233 hit with a neutron produces fission and releases neutrons (just like current uranium fission)
- TH232 absorbs neutron from fission and becomes TH233
- TH233 quickly decays into PA233
- PA233 decays into U233 in about a month thus restarting the cycle

You still need U233 to kickstart the process. The actual reactor fuel is a fluoride-salt mixture that is able to dissolve both uranium and thorium compounds.

[TeyshaBlue]

Do you realize that there's mixed Thorium-Uranium nuclear reactors already working, right? Did you even bother to read the article?

The cycle is:
- U233 hit with a neutron produces fission and releases neutrons (just like current uranium fission)
- TH232 absorbs neutron from fission and becomes TH233
- TH233 quickly decays into PA233
- PA233 decays into U233 in about a month thus restarting the cycle

You still need U233 to kickstart the process. The actual reactor fuel is a fluoride-salt mixture that is able to dissolve both uranium and thorium compounds.

Oh, so it's a Hybrid Thorium reactor. Probably a Toyota project.

[coyotes_geek]

Oh, so it's a Hybrid Thorium reactor. Probably a Toyota project.

Can't be. The private sector never invests in R&D.

[Drachen]

Do you realize that there's mixed Thorium-Uranium nuclear reactors already working, right? Did you even bother to read the article?

The cycle is:
- U233 hit with a neutron produces fission and releases neutrons (just like current uranium fission)
- TH232 absorbs neutron from fission and becomes TH233
- TH233 quickly decays into PA233
- PA233 decays into U233 in about a month thus restarting the cycle

You still need U233 to kickstart the process. The actual reactor fuel is a fluoride-salt mixture that is able to dissolve both uranium and thorium compounds.

Concept proven in the THTR in germany.

[ElNono]

It looks promising. The fact that uranium/plutonium reactors have been already retrofitted to run on thorium shows there's a path for progress. The major problem for a complete LFTR solution seems to be the materials that are used on the core. They would need to be much stronger than what's currently used as there's much more heat generated under that process.

It looks to me like this could be a good solution for nuclear power without the risk of nuclear weapon proliferation.

[boutons_deux]

Besides the nuclear fuel, there are two big financial aspects that can be fatal to ANY kind of nuclear plant construction. With no cap on for-profit insurance payouts, the private insurance industry wouldn't write the policies.

1. Construction insurance and operating insurance. Right now, because the private sector insurers' reluctance, the US govt (that same one so many of you love to hate) covers nuclear catastrophe costs beyond the insured cap of $11B.

2. Construction loans. Our beloved Wall St criminals will not lend the money

1) the construction cost + time overruns are infamously unpredictable. Hell, even locating a site and getting the licenses are unpredictable. They could add on penalties for delayed repayment and cost overruns, then the project would become horribly more expensive(profitable for Wall St), and the cost per kilowatt hour would be even more uncompetitive with coal and natural gas plants.

(Of course, if all the external costs of coal-fired plants were included in the kilowatt hour of coal, it would be much more expensive)

2) the interest rate (Wall St profit) will be lower than the returns Wall St and internationals player get from jacking each other off, from defrauding each other, and defrauding retail/fund customers in the Wall St/international rigged casinos.

iow, why would Wall St lend money on something as flakey as nuclear plant construction rather than sticking with the more certain, higher rate casino payback? In fact, Wall St casino winnings pay more than lending to the Real Economy.

And there's lots of controversy about fresh uranium supplies. The US hasn't bothered with recylcing spent fuel. France, yes mf'ing France, has:

"In France, well over 1000 metric tons of spent fuel is reprocessed every year without incident at the La Hague chemical complex, on the Normandy coast. La Hague receives all the spent fuel rods from France’s 59 reactors. The sprawling facility is operated by the state-controlled nuclear giant Areva, and has racked up a good environmental record. The French effort clearly shows that reprocessing does not need to be the dangerous mess that other countries, including the United States, have made of it in the past.

France uses an improved version of the 63-year-old Purex process (“plutonium-uranium extraction”), which was developed during the Manhattan Project. Areva says the separation equipment employed is more compact than its predecessors and generates less waste. The major products of the separation are uranium and plutonium. The uranium consists of the isotopes 235U and 238U, making up 95 percent of the spent fuel. The plutonium accounts for a little more than 1 percent.

Even the largest of France’s reactors, which can produce 1300 megawatts, generate just 20 canisters of high-level waste per year. According to Areva, it’s about a factor of 10 reduction in the mass of highly radioactive waste needing to be stored under the most stringent conditions, and a four- or fivefold reduction in volume relative to leaving a plant’s spent fuel unseparated."

http://www.theresilientearth.com/?q=content/mit-report-disputes-uranium-shortage-fallacy

[ManuBalboa]

Thorium, that's fking awesome. Inb4 the next nuke dropped is named Mjöllnir.

[Wild Cobra]

To be honest, I doubt I'll remember this thread 20 years from now :)

Don't get me wrong, I find it great that you are curious about everything. I just think it's funny that you tend to dismiss things out of hand just on a cursory amount of knowledge.

Where's your world famous skepticism when it comes to the resources you viewed? :D
Sciences as we understand them are pretty well established. I've toyed around with some hypothesis about how it could be achieved, but real doubtful it could be done. It falls along the same line as turning mercury into gold. Anyone show a proven method yet, after all these centuries of trying?

OK, they fluff the talk up nice about speaking of salt reactors. These are proven methods of using Uranium, and possibly plutonium for making power. Thorium is a whole different beast. As I pointed out before, it's half-life is so long, it is effectively inert. We would have no problem using it as alloys in everyday metals.

Here is the natural decay process of thorium:

http://upload.wikimedia.org/wikipedia/commons/thumb/1/1c/Decay_chain%284n%2CThorium_series%29.PNG/416px-Decay_chain%284n%2CThorium_series%29.PNG

the propose to change it to this:

http://upload.wikimedia.org/math/c/c/7/cc787a8bc2dadbf6fa3c9b1cbbae9d9e.png

but also adding neutron bombardment to the U-233 to change it to Ti-232 again. Now I would like to know how they plan to direct the neutrons at just the U-233 and Ti-232, without creating unwanted isotopes from the Th-233 and Pa-233. they are in a molten salt solution, where you cannot separate them.

I can name problem after problem that would have to be solved. the concept of the breeder reactor isn't such a bad idea. The U-233 can be used to create power. However, the trick is to still get more energy out of it than you put in to start with. You still have to put in a great deal of energy to change the Ti-232 to Ti-233. Another issue that occurs as the isotopes decay is they don't decay 100% to a desired form. The Pa-233 not only changes to U-233, but also Pa-232 then U-232.

The theories have been out there for decades to make thorium work. Nobody has created one yet that produces more power than it takes to drive the process.

Believe in perpetual motion also by chance?

[Wild Cobra]

Ok, I found an image that helps explain their proposal. I forgot where it was when I made the last post:

http://i181.photobucket.com/albums/x262/Wild_Cobra/science/thoriumcycle.jpg (http://energyfromthorium.com/wp-content/uploads/2010/04/suzanneHobbsThoriumEnergyCycle.jpg)

Looks like a proposed perpetual motion machine to me, to get more energy out than put in.

[Wild Cobra]

Do you realize that there's mixed Thorium-Uranium nuclear reactors already working, right? Did you even bother to read the article?

The cycle is:
- U233 hit with a neutron produces fission and releases neutrons (just like current uranium fission)
- TH232 absorbs neutron from fission and becomes TH233
- TH233 quickly decays into PA233
- PA233 decays into U233 in about a month thus restarting the cycle

You still need U233 to kickstart the process. The actual reactor fuel is a fluoride-salt mixture that is able to dissolve both uranium and thorium compounds.
Duh... No shit Sherlock.

Start counting the neutrons. Tell me if you see viability.

[Wild Cobra]

Concept proven in the THTR in germany.
Except it used a fairly good percentage of U-235, and was shut down because it wasn't economically feasible. It produced less than 400 megawatts of usable power.

[Wild Cobra]

It looks promising. The fact that uranium/plutonium reactors have been already retrofitted to run on thorium shows there's a path for progress. The major problem for a complete LFTR solution seems to be the materials that are used on the core. They would need to be much stronger than what's currently used as there's much more heat generated under that process.

It looks to me like this could be a good solution for nuclear power without the risk of nuclear weapon proliferation.
They run on partial thorium like cars today run on partial ethanol.

[ElNono]

[Removed irrelevant Sciences ramble]

Here is the natural decay process of thorium:

http://upload.wikimedia.org/wikipedia/commons/thumb/1/1c/Decay_chain%284n%2CThorium_series%29.PNG/416px-Decay_chain%284n%2CThorium_series%29.PNG

the propose to change it to this:

http://upload.wikimedia.org/math/c/c/7/cc787a8bc2dadbf6fa3c9b1cbbae9d9e.png


Correct


but also adding neutron bombardment to the U-233 to change it to Th-232 again.

Incorrect


Now I would like to know how they plan to direct the neutrons at just the U-233 and Th-232, without creating unwanted isotopes from the Th-233 and Pa-233. they are in a molten salt solution, where you cannot separate them.

Uh?

- You bombard the fluoride-salt fuel containing U-233 and Th-232 with neutrons.
- The U-233 nucleus fissions, releasing energy and neutrons, which in turn hit more U-233 and Th-232, thus creating the necessary chain reaction while at the same time leaving Th-233 as 'waste'
- The Th-233 is drained out as the process happens. It takes aprox 20 minutes for the Th-233 to decay into Pa-233. Plenty of time to make it outside of the core and into storage.
- The Pa-233 in storage decays into U-233 after aprox a month, which can be then mixed again with Th-232 into the fluoride-salt solution.

The naturally occurring Th-232 is the actual fuel of the reactor.


I can name problem after problem that would have to be solved. the concept of the breeder reactor isn't such a bad idea. The U-233 can be used to create power. However, the trick is to still get more energy out of it than you put in to start with. You still have to put in a great deal of energy to change the Th-232 to Th-233. Another issue that occurs as the isotopes decay is they don't decay 100% to a desired form. The Pa-233 not only changes to U-233, but also Pa-232 then U-232.

- The conversion of Th-232 to Th-233 is done for 'free' as part of the nuclear fission, by means of neutron absorption.
- The parasitic reactions that produces small amounts of U-232 impurity are well known, and does not prevent the system from working.


The theories have been out there for decades to make thorium work. Nobody has created one yet that produces more power than it takes to drive the process.

Believe in perpetual motion also by chance?

Who claimed anything remotely to that? :lol
Or you're just ready to move the goalposts?

The idea here is to make nuclear power safer, cheaper, less waste and without the possibility of building weapons from the byproducts.

Did you read the linked articles?

[ElNono]

Ok, I found an image that helps explain their proposal. I forgot where it was when I made the last post:

http://i181.photobucket.com/albums/x262/Wild_Cobra/science/thoriumcycle.jpg (http://energyfromthorium.com/wp-content/uploads/2010/04/suzanneHobbsThoriumEnergyCycle.jpg)

Looks like a proposed perpetual motion machine to me, to get more energy out than put in.

You obviously don't know how to interpret the graph if that's how you see it...

See those green dots in the arrows? They mean something... let's see if you figure out what it is...

[Wild Cobra]

Look, I hope I'm wrong on this idea. If it works as advertised, it would be awesome. I just don't see it happening. If the process didn't start with requiring neutrons to change thorium 232 to thorium 233, then we wouldn't have to count neutrons. In the end, you need to produce more neutrons than you use to make it viable. These other hybrid reactors that work use U-235 as a constant neutron source. U-233 is synthetic. The process to make it uses energy. As I said, looks like they expect perpetual motion to me.

[Wild Cobra]

You obviously don't know how to interpret the graph if that's how you see it...

See those green dots in the arrows? They mean something... let's see if you figure out what it is...
How about reading my post before that one.

[ElNono]

Duh... No shit Sherlock.
Start counting the neutrons. Tell me if you see viability.

:lol This is gold...
This is no hypothesis... this is actually working right now.

Let me ask you, where you don't see the 'viability'?


They run on partial thorium like cars today run on partial ethanol.

Exactly.

[Wild Cobra]

OK, I misspoke on the neutron to change the U-233 to Th-233. This neutron and more come from the U-233. We have a problem with our neutron count. We are losing more neutrons from the U-233 than we are using to convert the Th-232 to Th-233. the U-233 is depleting faster than it can be renewed without external neutron bombardment.

I would love it if you can show me I'm wrong.

[ElNono]

Look, I hope I'm wrong on this idea. If it works as advertised, it would be awesome. I just don't see it happening. If the process didn't start with requiring neutrons to change thorium 232 to thorium 233, then we wouldn't have to count neutrons. In the end, you need to produce more neutrons than you use to make it viable. These other hybrid reactors that work use U-235 as a constant neutron source. U-233 is synthetic. The process to make it uses energy. As I said, looks like they expect perpetual motion to me.

Production of neutrons to start a nuclear reaction is already tackled and solved by regular uranium/plutonium reactors (be it with particle accelerators or a plutonium core).
Again, the chain reaction is what generates the cascade of neutron generation. This is basic nuclear stuff, BTW.


How about reading my post before that one.

Your assumption that the process involved turning U-233 into Th-232 was wrong.

[Wild Cobra]

Production of neutrons to start a nuclear reaction is already tackled and solved by regular uranium/plutonium reactors (be it with particle accelerators or a plutonium core).
Again, the chain reaction is what generates the cascade of neutron generation. This is basic nuclear stuff, BTW.



Your assumption that the process involved turning U-233 into Th-232 was wrong.
That's fine. If I'm wrong about them changing the U-233 back to Th-232, so be it. I thought that was wrong anyway. There is still a neutron count problem.

[ElNono]

OK, I misspoke on the neutron to change the U-233 to Th-233. This neutron and more come from the U-233. We have a problem with our neutron count. We are losing more neutrons from the U-233 than we are using to convert the Th-232 to Th-233. the U-233 is depleting faster than it can be renewed without external neutron bombardment.

I would love it if you can show me I'm wrong.

U-233 releases about 2.6 neutrons per fission. Not all the remaining 1.6 is salvaged for breeding, but outside of Pu-239, you'll be hard pressed to find better fuel for breeding.

[ElNono]

Now that we dispelled the myth that there's a neutron count problem...

did you read the linked articles? :lol

[Wild Cobra]

Now that we dispelled the myth that there's a neutron count problem...

did you read the linked articles? :lol
OK, I have an issue with myself.

Every Th-232 that changes to Th-233 requires 1 neutron.

Each Th-233 eventually changes to U-232 or U-233.

Each U-x emit two neutrons. Nice trick getting 50% of them to target the thorium, but yes, I am technically wrong there. Don't know what I was thinking.

You still have the U-233 wanting to fissile out faster than it is replaced, by it's bombardment upon itself. Just how do we insure 50% of the neutrons strike the nuclei of the thorium? If we have less than 50%, the chain is broken.

As for reading the article. Yes, I did. I do remember them saying something about needing 2:1 neutrons, but forget if and how they fixed the issue.

[ElNono]

OK, I have an issue with myself.

Every Th-232 that changes to Th-233 requires 1 neutron.

Each Th-233 eventually changes to U-232 or U-233.

Each U-x emit two neutrons. Nice trick getting 50% of them to target the thorium, but yes, I am technically wrong there. Don't know what I was thinking.

You still have the U-233 wanting to fissile out faster than it is replaced, by it's bombardment upon itself. Just how do we insure 50% of the neutrons strike the nuclei of the thorium? If we have less than 50%, the chain is broken.

As for reading the article. Yes, I did. I do remember them saying something about needing 2:1 neutrons, but forget if and how they fixed the issue.

There's different approaches to breeding thermal reactors like this one. The LFTR model described in the article mentions mixing Th and U together into the fluoride-salt mixture, which makes the fuel actually liquid. Fluoride works because it can withstand the high temperatures of the cores. Once the fuel is in the core, you simply bombard it with neutrons ONCE to start the reaction. You end up with a chamber with a heck of a lot of heat, a lot of neutrons and a lot of Th-233 in the fluoride-salt liquid (which you drain). Controlling the reaction is different than a a non-breeding reactor though. Can't use the neutron-absorbing rods, you have to instead regulate the input of fuel into the core. You also have problems cooling, since you don't want to mess the Th-232 neutron absorption, so the material of the core needs to be a lot tougher and a good heat dissipation system is a must (and these are right now probably the biggest obstacles).
Other Thorium breeding reactors use a blanket system (this is what converted uranium reactors use). The core only holds the U-233, and the Th-232 is sitting outside of the core like a 'blanket' around it. Neutrons are allowed to reach the blanket area. So you only have fission in the center of the core producing heat and neutrons, which then get absorbed by the Thorium in the surrounding blanket. In this system, you can also use some plutonium as part of the fuel so you can generate excess neutrons (Pu-239 releases a little over 3 neutrons per fission)

Another thing which I think you have a misconception about, is that all the Th-232 you put in needs to be converted into Th-233. It doesn't. Even if some Th-232 gets stored as 'recyclable' fuel alongside the Th-233, only the Th-233 will decay to U-233 (and a very tiny amount of U-232 impurity) in the set time (about a month). But since you're then again mixing the U-233 with Th-232 in the fluoride-saline solution, it's not an impurity, it's actually welcome.

[MannyIsGod]

Smh