Why isn't thorium being considered or used as an alternative fuel source in nuclear reactors?

I'd agree with you....the current safety issues and worries with nuclear energy is going to prohibit investors from putting money into newer designs which are not as proven as the current BWR designs although thorium, fast-breeder reactors and molten salt designs can and do offer much longer energy production and in some cases, much safer. It's a shame that the cooling system issues with Japan's reactors were not better prepared. To me, it's a perfect example of how a little more redundancy and engineering could have saved a lot of grief.

Related info.....

Molten salt reactors.....

Invented in the USA in 1954

Not yet commercialized, even after 2 successful MSRs were built & operated

Meltdown proof

Does not produce weapons grade plutonium

Has inherent nonproliferation features

Thousands of years of energy

Its wastes are simpler and less toxic than current nuclear wastes

Only hundreds of years of storage versus thousands for the current wastes

Can burn the existing wastes (spent fuel)!

Higher thermal efficiencies (operates at a "Red Heat"; ~700° C [1260° F])

http://home.earthlink.net/~bhoglund/

"The Fuji Molten salt reactor is a japanese design that can run on thorium or a mix of thorium and Uranium or Plutonium. The project plan is to take 8 or 9 years to develop a miniFuji reactor and 12-15 years to develop a Fuji reactor. The R & D is mostly related to the details of the structural material and components.

-How to exactly modify the Hastelloy N alloy (increasing Cr and reducing Co)

-analyse and test low tensile strength parts like the tubing elbow

The projected costs for the reactor are about 20-25% less than a PWR and a little less than a LWR. "

"Currently nuclear reactors use about 100 to 200 tons of uranium every year. 10,000 to 20,000 kg of uranium per billion kWh. 200 to 400 times more uranium than the french msr design uses. The MSR can generate 1000 times less uranium and plutonium waste and everything else that is left over has a halflife of less than 50 years."

http://nextbigfuture.com/2007/12/fuji-molten-salt-...

http://nextbigfuture.com/2008/08/how-long-can-uran...

""Is nuclear energy renewable?

Generally 'renewable' relates to harnessing energy from natural forces which are renewed by natural processes, especially wind, waves, sun and rain, but also heat from the Earth's crust and mantle. Although it shares many attributes with technologies harnessing these natural forces – for instance radioactive decay produces much of the heat harnessed geothermally – nuclear power is usually categorised separately from ‘renewables’.

Conventional nuclear power reactors do use a mineral fuel and demonstrably deplete the available resources of that fuel. In such a reactor, the input fuel is uranium-235 (U-235), which is part of a much larger mass of uranium – mostly U-238. This U-235 is progressively 'burned' to yield heat. But about one-third of the energy yield comes from something which is not initially loaded in: plutonium-239 (Pu-239), which behaves almost identically to U-235. Some of the U-238 turns into Pu-239 through the capture of neutron particles, which are released when the U-235 is 'burned'. So the U-235 used actually renews itself to some extent by producing Pu-239 from the otherwise waste material U-238.

This process can be optimised in fast neutron reactors, which are likely to be extensively deployed in the next generation of nuclear power reactors. A fast neutron reactor can be configured to 'breed' more Pu-239 than it consumes (by way of U-235 + Pu-239), so that the system can run indefinitely. While it can produce more fuel than it uses, there does need to be a steady input of reprocessing activity to separate the fissile plutonium from the uranium and other materials discharged from the reactors. This is fairly capital-intensive but well-proven and straightforward. The used fuel from the whole process is recycled and the usable part of it increases incrementally.

As well as utilizing about 60 times the amount of energy from uranium, fast neutron reactors will unlock the potential of using even more abundant thorium as a fuel (see information page on Thorium). In addition, some 1.5 million tonnes of depleted uranium now seen by some people as little more than a waste, becomes a fuel resource. The consequence of this is that the available resource of fuel for fast neutron reactors is so plentiful that under no practical terms would the fuel source be significantly depleted.

Regardless of the various definitions of 'renewable', nuclear power therefore meets every reasonable criterion for sustainability, which is the prime concern."

http://www.world-nuclear.org/info/inf09.html

Thorium....

http://www.world-nuclear.org/info/inf62.html

Good question - maybe because there aren't any any commercial Thorium reactors in existence right now, and few companies are willing to take a 5 billion dollar (or more) gamble on unproven technology? Despite its faults, the industry knows how to build and run Uranium reactors, but Thorium reactors are foreign to them.

So I guess it's really a chicken-or-egg problem. There are no commercial thorium reactors yet because no one has built one. No one has built one yet because there are no commercial Thorium reactors.

It seems like all it would take would be a few government sponsored Thorium reactors to prove that they are economically viable and then industry will consider them.

excellent point. the technology is not mature. nuc reactors in use are often 2nd generation designs. they work; but aren,t as efficient as newer designs. it will take time and money to push this idea. politics does and will play a part in any changes toward nuclear energy. i think we, as a world, are shooting ourselves in the foot by burning coal. it has other, less polluting uses than being burned. i favor advanced nuc power. the semi literate state of most peoples awareness of nuclear power is going to be a stumbling block for many years.