Thorium -vs- Uranium

[Michael]

I read that Thorium is 3 times more abundant than Uranium, can be used as a nuclear fuel but it doesn't generate no where near the amount of hazardous waste (actually I'm not sure what kind of waste it does produce). It' much cleaner to extract from the Earth. It's byproducts can not be use in nuclear weapon manufacturing.

There is more Thorium energy than Uranium + Oil + Coal energy combined.
I'm pretty sure it doesn't produce CO2.
The various Crapistans have little more than anyone else.

WHY aren't we making use of this energy supply?!?
:bugeye:
Seriously, what am I missing here?

[Michael]

Actually, according to WIKI (http://en.wikipedia.org/wiki/Thorium#Thorium_energy_fuel_cycle) there are a number of companies looking to active Thorium Nuclear Reactors.

The USA has 1000 years of Thorium if consumed at current energy levels. That's pretty interesting. I wish we had media that was more informative rather than Hollywood punditry bullshit. Considering we're waging energy wars all over the world one would think this sort of information would be a little more of the discussion :shrug:

[AnWulf]

The history of why we use uranium instead of thorium and pressure water reactors (PWRs) instead of molten salt reactors (MSRs) is long and twisted.

Regardless, fast forward to today and we have the NRC which is unfamiliar with MSRs so it is reluctant to approve any. It has only somewhat recently approved a Gen III (I think it was a Gen III) reactors. The Gen IV MSRs aren't even on their radar.

I think that China is building or testing an LFTR (liquid fluoride thorium reactor). So maybe in a few years, we will latch onto that technology.

And yes, an MSR like a LFTR leaves less waste with much shorter half-lives. Much of the current waste could be recycled thru a LFTR and burned.

And the US has one of the most abundant supplies of thorium.

I can't post a link yet but go to youtube and search for Kurt Sorenson's 10-minute Ted-talk. It's good.

[nietzschefan]

mmm k so why DON'T they?

[Stoniphi]

Sciam recently ran an article on thorium reactors, they are indeed the 'next generation' of reactor.

The US boycotted sending nuke stuff to India so India is now in process of building a ton of these puppies, as is China. Since India has a lot of thorium it is a natural fit.

As to why the US has not done jack about implementing this technology:

26% of US citizens thought that Jesus was coming back for them Jan 1, 2010. Now they think it will be Jan 1, 2012. The same folks think the president was born in Kenya and is a 'secret Muslim'. Many of them thought that the world was going to end (again) last month.

In short - we have a lot of extremely ignorant and uneducated persons that think in a very unpractical and unscientific manner. Politicians are partially to blame for using science for political purpose. US scientists are also partially to blame for not possessing sufficient social skills to forward a serious scientific agenda for solving real world problems.

When we cannot use radiation to sanitize food because 'the public' will not buy it if it has been "nuked" it becomes extremely difficult to convince them that a reactor - any reactor will be safe. For these persons Halloween is every day of the year and they are absolutely sure that a reactor anywhere near them will turn them into flesh - eating zombies that not even Jesus can save. :(

Remember a short time back when US citizens bought up every grain of potassium iodide available to 'protect' them selves against nuclear fallout from Japan? Those are the people who have stopped US implementation of nuclear technology for the last 25 years. I think the term is "Luddites". :shrug:

Sadly, I believe that we are watching the US turn into a second - rate low tech society afraid of implementing new technology to solve serious problems while other 'less developed' countries surge ahead. Hopefully, world market forces will force the US to play catch - up again, as when the USSR started shooting people into space when we didn't even realize we were in a 'space race' until we were losing it. Note that as the Luddites are telling us that "Electric cars are a pipe dream", the Japanese are selling them to us on an ongoing basis and many more are on the way.

[Michael]

I can not believe that more than 1 in 4 Americans truly think the world is going to end. Sure, they do believe "Jabeezus" is a coming but it's usually "In my lifetime" not right around the corner ... at least I hope not! :o

Also, why did we choose to go the Uranium route and not the Thorium to begin with? Back when Americans had Can-Do attitude and got shit done. Why choose to go Uranium? I wonder if there weren't some special interest groups behind that?



Either way, it's really interesting how many diverse energy supplies there are around. I seem to remember the Japanese were going to pump up some sort of liquid methane found at the bottom of the deepest ocean crevices. BUT, then people started saying this might result in Japan being blown off Earth? Which is it??? By the Gods the media does a poor job of informing us of anything useful.

[chimpkin]

We had a big long debate about this before, and in the process of that...thorium cycle reactors make a whole lot less waste, what they do make only stays radioactive for 5,000 years, the reactors are much more self-regulating,and they can be used to recycle the spent fuel rods from light-water reactors.
They run really hot, such that they use molten sodium or molten lead as a coolant, and if a SCRAM is initiated, the lead-cooled ones turn into a less-dangerous leaden lump.

The only objection? they make plutonium, and so are a proliferation hazard...and, they are nuclear at all.
I personally think we should maximize use of wind, water, wave and solar before using nuclear. But that said, of nonrenewables, thorium-cycle-reactors are probably the least objectionable technology we have.

I am going to bed, if y'all want references on all that my tired butt will dig them up tomorrow evening at work.

[Stoniphi]

Japan is in process of tapping their offshore reserves of natural gas hydrates. There is a lot of gas trapped in ice at the bottom of the ocean and it represents a bunch of cleaner-than-coal-or-oil energy. Hydrates are gas that is trapped in water ice. When it is warmed the gas escapes. Sometimes this has happened naturally to large areas resulting in substantial geologic events. There is a lot of hydrate offshore of the Americas as well and plans are in process to tap these reserves as well.

From Wiki:


Thorium as a nuclear fuel
[edit] Benefits and challenges

Thorium can be used as fuel in a nuclear reactor, and it is a fertile material, which allows it to be used to produce nuclear fuel in a breeder reactor. In 1997, the U.S. Energy Department underwrote research into thorium fuel, and research was also begun in 1996 by the International Atomic Energy Agency (IAEA), to study the use of thorium reactors. Nuclear scientist, Alvin Radkowsky, of Tel Aviv University in Israel, founded a consortium to develop thorium reactors, which included other companies: Raytheon Nuclear Inc., Brookhaven National Laboratory, and the Kurchatov Institute in Moscow.[17] Radkowsky was chief scientist in the U.S. nuclear submarine program directed by Admiral Hyman Rickover and later headed the design team which built the USA's first civilian nuclear power plant at Shippingport, Pennsylvania, which was a scaled-up version of the first naval reactor.[17] Some countries, including India, are now investing in research to build thorium-based nuclear reactors. A 2005 report by the International Atomic Energy Agency discusses potential benefits along with the challenges of thorium reactors.[18] India has also made thorium-based nuclear reactors a priority with its focus on developing fast breeder technology.[19][20]

Some benefits of thorium fuel when compared with uranium were summarized as follows:[21]

Weapons-grade fissionable material (233U) is harder to retrieve safely and clandestinely from a thorium reactor;
Thorium produces 10 to 10,000 times less long-lived radioactive waste;
Thorium comes out of the ground as a 100% pure, usable isotope, which does not require enrichment, whereas natural uranium contains only 0.7% fissionable U-235;
Thorium cannot sustain a nuclear chain reaction without priming,[22] so fission stops by default.

However, unlike uranium-based breeder reactors, thorium requires irradiation and reprocessing before the above-noted advantages of thorium-232 can be realized, which makes thorium fuels initially more expensive than uranium fuels.[14] But experts note that "the second thorium reactor may activate a third thorium reactor. This could continue in a chain of reactors for a millennium if we so choose." They add that because of thorium's abundance, it will not be exhausted in 1,000 years.[23]

The Thorium Energy Alliance (TEA), an educational advocacy organization, emphasizes that "there is enough thorium in the United States alone to power the country at its current energy level for over 1,000 years."[24]
[edit] Thorium energy fuel cycle
Main article: Thorium fuel cycle

Although not fissile itself, 232Th will absorb slow neutrons to produce, after two beta decays, 233U, which is fissile.[14] Hence, like 238U, it is fertile. Also, preparation of thorium fuel does not require isotopic separation.

The thorium fuel cycle creates 233U, which, if separated from the reactor's fuel, can be used for making nuclear weapons. This is why a liquid-fuel cycle (e.g., MSR or molten salt reactor) is preferred — only a limited amount of 233U ever exists in the reactor and its heat-transfer systems, preventing any access to weapons material; however the neutrons produced by the reactor can be absorbed by a thorium or uranium blanket and fissile 233U or 239Pu produced. Also, the 233U could be continuously extracted from the molten fuel as the reactor is running. Neutrons from the decay of uranium-233 can be fed back into the fuel cycle to start the cycle again.[14]

The neutron flux from spontaneous fission of 233U is negligible. 233U can thus be used easily in a simple gun-type nuclear bomb design.[25] In 1977, a light-water reactor at the Shippingport Atomic Power Station was used to establish a 232Th-233U fuel cycle. The reactor worked until its decommissioning in 1982.[26][27][28] Thorium can be and has been used to power nuclear energy plants using both the modified traditional Generation III reactor design and prototype Generation IV reactor designs. The use of thorium as an alternative fuel is one innovation being explored by the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO),[29] conducted by the International Atomic Energy Agency (IAEA).

Unlike its use in MSRs, when using solid thorium in modified light water reactor (LWR) problems include: the undeveloped technology for fuel fabrication; in traditional, once-through LWR designs potential problems in recycling thorium due to highly radioactive 228Th; some weapons proliferation risk due to production of 233U; and the technical problems (not yet satisfactorily solved) in reprocessing. Much development work is still required before the thorium fuel cycle can be commercialized for use in LWR. The effort required has not seemed worth it while abundant uranium is available, but geopolitical forces (e.g. India looking for indigenous fuel) as well as uranium production issues, proliferation concerns, and concerns about the disposal/storage of radioactive waste are starting to work in its favor.
[edit] Commercial nuclear power station

India's Kakrapar-1 reactor is the world's first reactor which uses thorium rather than depleted uranium to achieve power flattening across the reactor core.[30] India, which has about 25% of the world's thorium reserves, is developing a 300 MW prototype of a thorium-based Advanced Heavy Water Reactor (AHWR). The prototype is expected to be fully operational by 2011, after which five more reactors will be constructed.[31] Considered to be a global leader in thorium-based fuel, India's new thorium reactor is a fast-breeder reactor and uses a plutonium core rather than an accelerator to produce neutrons. As accelerator-based systems can operate at sub-criticality they could be developed too, but that would require more research.[32] India currently envisages meeting 30% of its electricity demand through thorium-based reactors by 2050.

Briefly, a thorium reactor is a sphere full of circulating molten thorium with a small piece of uranium 233 stuck in it to ignite the nuclear reaction. There is a metal plug at the bottom of the sphere and a large concrete tray under the sphere. The thorium circulates past the sample of U - 233. As it does, it picks up a few neutrons from the uranium which changes some of the thorium to u - 233 and starts the reaction. As the thorium heats up from the nuclear reaction the heat is conveyed away by the liquid salt or lead system. That heat is then used to heat water into steam to run standard steam turbine electric generators. The fluid is then recycled (the heat conveyor is a closed system that is separate from the reaction chamber).

If the reaction begins to get too hot the metal plug at the bottom of the sphere melts and allows the molten thorium to pour into the concrete tray under the sphere. The tray is big enough that when full of the molten thorium, the metal forms a 2 inch thick plate. This stops the nuclear reaction without further intervention as the reaction is dependent on the physical shape of the nuclear containment sphere to maintain itself. The nuclear reaction cannot continue when the thorium is in a thin plate form. This makes the reactor very safe from the get - go.

That rare earth mine in California that was shut down due to toxic waste in the mine tailings - the "waste" was mostly thorium and uranium. Thorium is very common compared to uranium and vastly safer to use for power generation, thus the interest in thorium reactors. At least in technologically progressive nations. :o

[Stoniphi]

Oh yeah - as Chimpi knows, I fully support using renewables and geothermal as our primary power sources and I have put my money where my mouth is by living with solar energy in my home for the last 30 years.

[Michael]

Does the solar energy pay itself off? I mean, without government incentives like tax breaks? I know a family that has always had windmills. Whenever they move they build a new one. They're pretty big.

I own stock in bio-fuel companies. Not sure if they'll be worth anything in the future, but, I also try to put some money were my heart is :o

[leopold]

Also, why did we choose to go the Uranium route and not the Thorium to begin with? Back when Americans had Can-Do attitude and got shit done. Why choose to go Uranium? I wonder if there weren't some special interest groups behind that?
the answer to this is simple.
uranium could be made into a bomb.
after the crash course in bomb making was over then the dregs fell to the corporations to make use of it .
vis nuclear power.

the same can be said of the "space race"
russia proved its capability to strike the US by launching sputnik.
at that time the US couldn't even get a missile to hit the west coast of africa.
the military got scared, the space race was born.
thank god JFK came along and pointed a finger at the moon and said "let's go there instead".

[billvon]

WHY aren't we making use of this energy supply?!? Seriously, what am I missing here?

Some drawbacks:

1) A thorium reactor won't start itself; you still have to seed it with enriched uranium, so it doesn't solve the proliferation problem.

2) Reactor design is a little more complex. Molten salt reactors are often proposed for use with the thorium fuel problems, but there are obvious problems with containing and circulating 800 degree C molten salt within a reactor.

That being said, thorium reactors are good options. They're certainly not the only options, though; CANDU reactors are proliferation-proof (no enrichment needed) and are similar in design to current PWR reactors so we have a good amount of experience with them. PBMR's have a lot of pluses and minuses as well.

And of course designs like the GE AP600 take conventional reactors and add a host of passive safety features to them; such reactors have the benefit of being the result of 70 years of research and actual working experience behind them. And when you're a utility company that's about to gamble your entire business on a new generation facility there's something to be said for using a proven technology.

[rcscwc]

Thorium can start with plutonium core, in what is called a fast breeding reactor. This produces more plutonium than is consumed. India is one of the poineeers of this technology. Plus India has abundant deposits of thorium and that too nearly asking for being shovelled and loaded.

[Walter L. Wagner]

Converting of Th-232 into U-233 is not difficult if placed in a breeder environment (low neutron flux). Because they are chemically different, they can be chemically separated. U-233 is superior to U-235 or Pu-239 for weapons. Hence, a great concern for proliferation.

[Stoniphi]

...Does the solar energy pay itself off? ..

I built my direct gain type 1 passive South wall solar heater 32 years ago on the ground floor. Despite leaky backdraft dampers and poor insulation it cut my heating bill by 24% over the winters.

I then moved it to the second floor S wall and it did the same job for 15 years. I am now in the process of replacing the exterior wood framing with exterior plastic, the galvanized retaining screws and washers with stainless steel and the duct tape that seals the glass panels with aluminum roofing repair tape. I have engineered a new mechanical airtight backdraft damper to replace the commercial ones and am converting the unit from type 1 to type 3 passive. This should eliminate the need to service the unit for at least 25 years and enable me to lock it down in the evening, stopping any leakage and improving its efficiency. It consumes no energy and produces heat in the winter. While it can act as a black - body thermal re-radiator in the summer it is shaded from the direct sun then and the heat gain is minimal until the sun angle is below 45 degrees. I may install a heat dump on it anyways as long as I have a scaffold against the side of the house, to save internal wear and tear from pooled non-flowing heat.

It has paid for itself and the knowledge that I have gained from living with solar heat for the last 32 years is priceless. If the improvements work out as well as they appear to be I may pursue hooking up with an area contractor to sell them. Or then again I may just feel smug about having built it. :)