Thorium Heavy Water and Thorium Liquid Fuel Reactors

[William]

The discussion about AGW is a distraction from the discussion of pros/cons of alternative energy sources to fossil fuels. If one understand the limitations of the alternatives, it appears nuclear is the best alternative.

The US pressurized enriched (Uranium 238 enriched with 235) reactor design was selected as the standard as it produces plutonium which is required for nuclear weapons.

Thorium is roughly four times as abundant as uranium and does not produce significant amounts of plutonium.

India is a developing a commercial heavy water thorium reactor (the hydrogen in heavy water, deuterium has an extra neutron).


http://www.barc.ernet.in/publication...chapter1/1.pdf

http://www.theregister.co.uk/2011/02...a_thorium_bet/

The thorium fuel cycles produce almost no plutonium, and fewer higher-isotope nasties, the long-lived minor actinides. Thorium is much more abundant than uranium, and the reduced plutonium output eases proliferation concerns. The energy output per tonne is also attractive, even though thorium isn't itself a fissile material.
Thorium reactors are also safer, with the fuel contained in a low-pressure reactor vessel, which means smaller (sub-500MWe) reactors may be worth building. The first Molten-Salt Breeder prototype was built at Oak Ridge in 1950, with an operational reactor running from 1965 to 1969. Six heavy-water thorium reactors are planned in India, which has the world's largest thorium deposits.The design has also had its champions in Europe, but planning restrictions and a continent-wide policy obsession with conservation and renewables have seen little commercial action. But that might change.

A private company founded by Kazuo Furukawa, designer of the Fuju reactor, called International Thorium Energy & Molen-Salt Technology Inc (iThEMS) aims to produce a small (10KW) reactor within five years. Furukawa is aiming for a retail price of 11 US cents per kWh (6.8p per kWh).
Just to put that into perspective, the UK's feed-in tariff ranges from 34.5p/kWh for a small wind turbine to 41.3p/kWh for a retro-fitted solar installation, making a personal LFTR much more attractive than an additional garage. Just tell them you've got an enormous solar panel.

http://energyfromthorium.com/2010/07...ntist-readers/

The objective for energy cheaper than from coal is $0.03/kWh and a capital cost of $2/watt of generating capacity. How can the liquid fluoride thorium reactor produce energy cheaper than from coal?

Fuel costs. Thorium fuel is plentiful and inexpensive; one ton worth $300,000 can power a 1,000 megawatt LFTR for a year – enough power for a city. Just 500 tons would supply all US electric energy for a year. The US government has 3,752 tons stored in the desert. US Geological Survey estimates reserves of 300,000 tons, and Thorium Energy claims 1.8 million tons of ore on 1,400 acres of Lemhi Pass, Idaho. Fuel costs for thorium would be $0.00004/kWh, compared to coal at $0.03/kWh.
Capital costs. The 2009 update of MIT’s Future of Nuclear Power shows new coal plants cost $2.30/watt and PWR nuclear plants cost of $4.00/watt. The median of five cost studies of molten salt reactors from 1962 to 2002 is $1.98/watt, in 2009 dollars. The following are fundamental reasons that LFTR plants will be less costly than coal or PWR plants.

Pressure. The LFTR operates at atmospheric pressure, without a massive reactor vessel pressurized to 160 atmospheres, and without a large containment dome needed to contain any accidentally released radioactive materials propelled by pressurized steam. One concept for the smaller LFTR containment structure is a concrete building below grade, with a concrete cap at grade level to resist aircraft impact.

Safety. PWRs are safe because of defense in depth – multiple, independent, redundant systems engineered to control faults. LFTR’s intrinsic safety keeps such costs low. A molten salt reactor can’t melt down because the core is already molten — its normal operating state. The salts are solid at room temperature, so if a reactor vessel, pump, or pipe ruptured the salts would spill out and solidify. There is no explosion potential because the pressure in the reactor is atmospheric. If the temperature of the salt rises too high, a solid plug of salt in a drain pipe melts and the fuel drains to a dump tank; the Oak Ridge researchers turned the reactor off this way on weekends.

[Glom]

Yes, thorium is good. It's an irony that the oppositionists in holding back nuclear development have prevented progress to be flavours of the technology.

[William]

The word “ironic” is not strong enough to label the mass stupidity which I would assume is driven by hysteria of the “green” movement.

There appears to be complete ignorance of basic engineering facts and limitations and no understanding of costs.

There is sufficient thorium and natural uranium to power the world for 1000s of years, using thorium nuclear reactors and natural heavy water uranium nuclear reactors.

A heavy water reactor is failsafe. If the heavy water evaporates the reaction shutdowns as the heavy water is required to slow down neutrons to enable the reaction to occur.

[starcanuck64]

Thorium has it's advantages, it also has some of the same challenges of fast reactors.

The Technetium-99 in the waste issue is probably not that serious and proliferation from U-233 is difficult due to the presence of U-232.

I still think fast reactor designs that consume most of the fissile material and can "burn" transuranic actinides currently stored in large waste deposits are also a good option for energy demand.

[Tensor]

The word “ironic” is not strong enough to label the mass stupidity which I would assume is driven by hysteria of the “green” movement.

There appears to be complete ignorance of basic engineering facts and limitations and no understanding of costs.

There is sufficient thorium and natural uranium to power the world for 1000s of years, using thorium nuclear reactors and natural heavy water uranium nuclear reactors.

A heavy water reactor is failsafe. If the heavy water evaporates the reaction shutdowns as the heavy water is required to slow down neutrons to enable the reaction to occur.

It's just not the green movement that has concerns about the costs and current problems with thorium reactors. The International Atomic Energy Agency (IAEA) and the World Nuclear Association are neither stupid nor ignorant of either the costs or engineering. Both of those organizations are well aware of the benefits of thorium (or thermal) reactors, but they are alos realistic about the problems involved with those same reactors. Both organizations suggest more research into solving the noted problems to enable the use of this technology. This hardly sounds as if their objections are driven by the hysteria of the green movement.

You look completely foolish when you take your information from a site (energyfromthorium) that has something to gain from pushing the idea, and ignoring sites, such as the IAEA, that looks at both the good and bad of the idea. For example, the IAEA document give the exact reasoning for the cost estimates, something the quote from energyfromthorium, doesn't do. We have no way of knowing whether the cost estimates from energyfromthorium are valid or not, as they don't provide us with their methodology.

I'd say, let's solve the problems and see if large scale commercial use is practical. If it is, fine, let's use it.

[Ronald Brak]

The reason why nuclear power is not being used to power the computer I am typing this on is cost. As fuel is only a very small fraction of the total cost of nuclear power, the use of thorium doesn't overcome this problem.

[BigDon]

Aren't you an Aussie Mr. Brak?

In California, the cost of overcoming all the lawsuits would have to be factored in.

[Ronald Brak]

Yes, I'm an Aussie. I live in South Australia which is a major uranium producer and has I think the largest deposit of uranium in the world. This is also the state with the highest wholesale electricity price and we still don't have any reactors.

[BigDon]

Like the Nigerian oil region where people can't afford gasoline?

There was an issue in the Philipines when I was there about plantations that exported ALL of their produce and so even though this one area grew more bananas than anywhere else, none of the local populace could afford them.

Are your uranium miners for or against Austrailian nuclear power? (If they're making more money selling it abroad...)

[Ivan Viehoff]

You may have noticed, eg recent Finnish case, that we find it hard enough to build a uranium reactor to a well-known technology without problems that end up doubling the total cost.

A few research thorium reactors were built. Likewise some research fast breeder reactors were built. There is a reason the designs were not selected for commercial implementation, ie, technical difficulties. Technical difficulties can cost a lot of money.

This is why some people have suggested that what we need to do with nuclear is to build much smaller reactors, which will be less efficient thermally, but give us the opportunity to replicate them many more times. That way we will get good at building them and will be able to mass-produce them to a standard cost, rather than hand-craft every one, as seems to happen at the moment.

[Van Rijn]

Part of the cost currently in nuclear is due to technical difficulties. But politics and NIMBY (Not In My Backyard) raises costs too.

I want to see more energy R&D, not just nuclear. But advanced reactor technology (both uranium and thorium approaches) should get attention. Long term fuel costs aren't really a big issue now, though. Inherently safe reactors that are easier and cheaper to run, though, would be good. Reactors that didn't have to be refueled for decades or possibly for the life of the reactor would be good, not so much because of lower fuel costs, but because of simpler operations, and lower waste production (and less hassle dealing with it).

I don't know if uranium or thorium is best for now. I do think they should both be looked at.

[William]

You may have noticed, eg recent Finnish case, that we find it hard enough to build a uranium reactor to a well-known technology without problems that end up doubling the total cost.

A few research thorium reactors were built. Likewise some research fast breeder reactors were built. There is a reason the designs were not selected for commercial implementation, ie, technical difficulties. Technical difficulties can cost a lot of money.

This is why some people have suggested that what we need to do with nuclear is to build much smaller reactors, which will be less efficient thermally, but give us the opportunity to replicate them many more times. That way we will get good at building them and will be able to mass-produce them to a standard cost, rather than hand-craft every one, as seems to happen at the moment.

The US selected the U235 enriched uranium boiling water design reactor as its standard reactor as that fuel cycle produces plutonium which is required for weapons production. If the “greens” were interested in backing technology that is capable of being a long term solution, they would be pushing Western Countries to rapidly develop and implement Thorium reactors.

The Chinese, Russians, and India currently have Thorium based reactor designs.

http://www.barc.ernet.in/publication...chapter1/1.pdf

Thorium is 3 to 4 times more common than Uranium and a Thorium reactor can be designed to effectively use all of the Thorium. Thorium can provide power for all nations for 1000s of years.

Thorium, while not without its issues, has much to commend it over uranium. It is widely available in the earth’s crust; the US, for example, has vast reserves as a result of old rare-earth mining waste and Norway has so much it is contemplating research as a second renaissance once oil and gas runs out. The technology can also consume old weapons-grade nuclear fuel and uranium power plant waste, helping resolve a growing storage problem with conventional technology. According to wiki sources, thorium produces 10 to 10,000 times less long-lived radioactive waste. The metal comes out of the ground as a 100% pure, usable isotope, which does not require enrichment, whereas natural uranium contains only 0.7 percent fissionable U-235.

Many consider the MSR the best long term option, but there is a second thorium-based reactor process more closely aligned to existing technologies; this requires an external “accelerator source” of neutrons to maintain the reaction, and without the existing accelerator the reaction stops. Some, such as Nobel laureate Carlo Rubbia at CERN (European Organization for Nuclear Research) proposed using a photon beam while others use a plutonium core such as that under development by India. According to sources quoted in Wikipedia, India’s Kakrapar-1 reactor is the world’s first reactor that uses thorium with a plutonium accelerator in the reactor core. India, which has about 25 percent of the world’s thorium reserves, is developing a 300 MW prototype of a thorium-based Advanced Heavy Water Reactor. The prototype is expected to be fully operational by 2011, after which five more reactors will be constructed. India currently foresees meeting 30 percent of its electricity demand through thorium-based reactors by 2050.

The Indian Advanced Heavy Water Reactor (AHWR) is designed and developed to achieve large-scale use of thorium for the generation of commercial nuclear power. This reactor will produce most of its power from thorium, with no external input of uranium 233, in the equilibrium cycle.
AHWR is a 300 MWe, vertical, pressure-tube type, boiling light water cooled, and heavy water moderated reactor. The reactor incorporates a number of passive safety features and is associated with a fuel cycle having reduced environmental impact. At the same time, the reactor possesses several features, which are likely to reduce its capital and operating costs.

Important Safety Features of AHWR
- Slightly negative void coefficient of reactivity.
- Passive safety systems working on natural laws. –
- Large heat sink in the form of Gravity Driven Water Pool with an inventory of 6000 m3 of water, located near the top of the Reactor Building. .-
- Removal of heat from core by natural circulation. –
- Emergency Core Cooling System injection directly inside the fuel. .
-Two independent shutdown systems.

AHWR employs natural circulation for cooling the reactor core under operating and shutdown conditions. All event scenarios initiating from non-availability of main pumps are, therefore, excluded. The Main Heat Transport (MHT) System transports heat from fuel pins to steam drum using boiling light water as the coolant. The MHT system consists of a common circular inlet header from which feeders branch out to the coolant channels in the core. The outlets from the coolant channels are connected to tail pipes carrying steam-water mixture from the individual coolant channels to four steam drums. Steam is separated from the steam-water mixture in steam drums, and is supplied to the turbine. The condensate is heated in moderator heat exchangers and heaters and is returned to steam drums by feed pumps. Four down comers connect each steam drum to the inlet header. Emergency Core Cooling System (ECCS) is designed to remove the core heat by passive means in case of a postulated Loss of Coolant Accident (LOCA). In the event of a rupture in the primary coolant pressure boundary, the cooling is initially achieved by a large flow of water from the accumulators. Later, cooling of the core is achieved by the injection of cold water from a Gravity Driven Water Pool (GDWP) located near the top of the reactor building.

[Van Rijn]

Thorium is 3 to 4 times more common than Uranium and a Thorium reactor can be designed to effectively use all of the Thorium.

And a uranium reactor can be designed to effectively use all the uranium. I did a double take on this line:

The metal comes out of the ground as a 100% pure, usable isotope, which does not require enrichment, whereas natural uranium contains only 0.7 percent fissionable U-235.

Thorium 232 isn't fissile, unlike U235, so the reality is that thorium reactors must be breeders, to produce more U233 than consumed. There is essentially no fissile material that could be enriched, unlike U235 in natural uranium. There will need to be a neutron source to get the breeding going, so uranium enters the picture anyway, or maybe an accelerator.

Uranium, on the other hand, can be used right out of the ground, no breeding or enrichment required (as in CANDU reactors) though in practice there usually is U235 enrichment. And in any uranium thermal reactor, a good portion of the energy actually comes from plutonium produced from the U238 that makes up the bulk of the uranium.

Thorium can provide power for all nations for 1000s of years.

So can uranium, especially if you use breeder reactors. Also, the amount of economically available uranium rather dramatically depends on price. There is a lot of uranium in the world if you can work with lower concentrations.

Mind you, I have no problem in seeing R&D go to thorium technology. It probably does have a part to play, it just isn't as cut and dried as you seem to think it is.

[Tensor]

The US selected the U235 enriched uranium boiling water design reactor as its standard reactor as that fuel cycle produces plutonium which is required for weapons production.

That's not true. It was primarily cost. Unless you have something that says otherwise. Even today, even in India, their Fast Breeder Reactor costs are so much more than their previous breeder reactors, they are looking into a cheaper fuel for them, Uranium.

If the “greens” were interested in backing technology that is capable of being a long term solution, they would be pushing Western Countries to rapidly develop and implement Thorium reactors.

Yeah, it's not quite that simple. Of course, it doesn't appear as if you've even bothered to read the IAEA paper I provided a link to.

The Chinese, Russians, and India currently have Thorium based reactor designs.

http://www.barc.ernet.in/publication...chapter1/1.pdf

None of which are currently in COMMERCIAL operation. Forgot to mention that I see.

Thorium is 3 to 4 times more common than Uranium

But not in all countries. Who's gonna convince India to give up their Thorium?

and a Thorium reactor can be designed to effectively use all of the Thorium.

And Uranium reactors can be designed to effectively use all the Uranium.

Thorium can provide power for all nations for 1000s of years.

Yeah, and with breeding, there's enough Uranium for over a billion years of operations, at least according to Wiki. And I doubt thorium will power all nations. India's got between one to two thirds of the worlds supply. Their main driver of developing thorium reactors is that they have large thorium deposits. You think they'll give up their thorium, if their power grid is based on it? Doubtful. So who else is able to use it? Western Europe? Nope, no reserves, and according to you, those with reserves should be developing thorium reactors. And, any country that bets their long term power needs on thorium won't be parting with their thorium either.

I also notice that you've pretty much given up on providing the location of the quotes you present. Not to mention, it appears that you continue to ignore limits or restrictions on those quotes you do present.

[Ronald Brak]

Like the Nigerian oil region where people can't afford gasoline?

No, we are quite ludicriously rich. Stacking groceries on supermarket shelves pays about $20 US an hour here. We do have higher than OECD average interest rates which hurts the case for nuclear power, but the reason nuclear reactors weren't built here pre-Chernobyl is because our other generating options were cheaper. Cheap coal in most of Australia, and less cheap gas in South Australia.

Are your uranium miners for or against Austrailian nuclear power? (If they're making more money selling it abroad...)

Well, I'm sure miners would like to sell more uranium, but nuclear power's not really an issue in Australia. No power company wants to build a reactor so it doesn't matter how much people are for or against nuclear power in Australia, it's not going to make any difference until a power company decides they can make money out of it and asks for permission to build one.

[tusenfem]

The US selected the U235 enriched uranium boiling water design reactor as its standard reactor as that fuel cycle produces plutonium which is required for weapons production. If the “greens” were interested in backing technology that is capable of being a long term solution, they would be pushing Western Countries to rapidly develop and implement Thorium reactors.

And that is enough of political content, William.
I don't care if you like or dislike the greens, the dems or the reps or whatever other parties there are.
If you have a scientific claim then bring that, don't put in the politics.
Next time you will be infracted.

[starcanuck64]

Part of the cost currently in nuclear is due to technical difficulties. But politics and NIMBY (Not In My Backyard) raises costs too.

I want to see more energy R&D, not just nuclear. But advanced reactor technology (both uranium and thorium approaches) should get attention. Long term fuel costs aren't really a big issue now, though. Inherently safe reactors that are easier and cheaper to run, though, would be good. Reactors that didn't have to be refueled for decades or possibly for the life of the reactor would be good, not so much because of lower fuel costs, but because of simpler operations, and lower waste production (and less hassle dealing with it).

I don't know if uranium or thorium is best for now. I do think they should both be looked at.

Pretty much what I think.

[Ronald Brak]

We've just passed a carbon tax through Parliment. (And passing it was slightly less difficult than I thought it would be.) This improves the economics of nuclear power here in Australia, but I still very much doubt will see any one putting money down to build a commercial reactor.

[BigDon]

We've just passed a carbon tax through Parliment. (And passing it was slightly less difficult than I thought it would be.) This improves the economics of nuclear power here in Australia, but I still very much doubt will see any one putting money down to build a commercial reactor.

So they're actually going to get somebody to tax air.

While we're all one be happy family here on BAUT, Ron, both you and I are nationals of very different countries. (And I'm sure you're as patriotic as I am.) I don't see this as benefiting my country.

[Torsten]

So they're actually going to get somebody to tax air.

It's not a tax on air. The tax on carbon is like a fee for disposing of a certain class of waste into the atmosphere, i.e., carbon dioxide derived from fossil carbon.

I think there are similarities with the concept of paying an environmental fee up-front when buying a lead acid battery, car tires, or a can of paint. In many jurisdictions there is a tipping fee for disposing of garbage at the dump.

While we're all one be happy family here on BAUT, Ron, both you and I are nationals of very different countries. (And I'm sure you're as patriotic as I am.) I don't see this as benefiting my country.

We also pay a carbon tax in my province. It is presently $25/tonne of CO2 equivalent emissions, and will rise to $30/tonne next year. To help relate this to a familiar commodity, gasoline, it works out to 5.56 cents per litre of the $1.28 total I'm paying at the pump here right now. My next vehicle will be more fuel efficient.

ETA: Oops, just realized this is the reactor thread. But I hope it's clear that the effect of the tax is to make fossil energy less appealing.