05 September 2010

Thorium - a replacement for fossil fuels?

Excerpts from an interesting article by the business editor at the Telegraph -
If Barack Obama were to marshal America’s vast scientific and strategic resources behind a new Manhattan Project, he might reasonably hope to reinvent the global energy landscape and sketch an end to our dependence on fossil fuels within three to five years...

(W)ork by Nobel laureate Carlo Rubbia at CERN (European Organization for Nuclear Research) on the use of thorium as a cheap, clean and safe alternative to uranium in reactors may be the magic bullet we have all been hoping for...

...a tonne of the silvery metal... produces as much energy as 200 tonnes of uranium, or 3,500,000 tonnes of coal. A mere fistful would light London for a week. Thorium eats its own hazardous waste. It can even scavenge the plutonium left by uranium reactors, acting as an eco-cleaner.

Thorium is so common that miners treat it as a nuisance, a radioactive by-product if they try to dig up rare earth metals. The US and Australia are full of the stuff. So are the granite rocks of Cornwall. You do not need much: all is potentially usable as fuel, compared to just 0.7pc for uranium...

After the Manhattan Project, US physicists in the late 1940s were tempted by thorium for use in civil reactors. It has a higher neutron yield per neutron absorbed. It does not require isotope separation, a big cost saving. But by then America needed the plutonium residue from uranium to build bombs.

"They were really going after the weapons," said Professor Egil Lillestol, a world authority on the thorium fuel-cycle at CERN. "It is almost impossible make nuclear weapons out of thorium because it is too difficult to handle. It wouldn’t be worth trying." It emits too many high gamma rays...

Brussels turned to its technical experts, who happened to be French because the French dominate the EU’s nuclear industry. "They didn’t want competition because they had made a huge investment in the old technology..." The UK has shown little appetite for what it regards as a "huge paradigm shift to a new technology".  Too much work and sunk cost has already gone into the next generation of reactors, which have another 60 years of life...

Thorium-fluoride reactors can operate at atmospheric temperature. "The plants would be much smaller and less expensive. You wouldn’t need those huge containment domes because there’s no pressurized water in the reactor..."
I find it telling that the technology was never pursued because the material could not be used for weapons.  Sad.

5 comments:

  1. Well the positives sound extremely good, but are there any negatives/dangers?

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  2. As best I can tell the major "negative" is that it will drive existing energy companies out of business.

    It also seems to be very expensive to establish, so in a country whose businesses never look beyond the next quarter it seems unlikely to fly. China will probably do it.

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  3. It's not the only idea for a new kind of nuclear reactor. Take a look at http://www.ted.com/talks/bill_gates.html#926858085310076753
    That's a reactor that will consume existing nuclear waste and fortunately has some financial backing in the form of Bill Gates.

    India will certainly be a huge market for any new kinds of nuclear, and hopefully also a developer.

    I hope we can get over the nuclear vs renewables arguments and agree that we may as well have both, redirecting money and support away from fossil fuels!

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  4. Having done some more reading, I think the nuclear industry already has a reasonable plan. There's no need to launch some huge, expensive project to try and develop this to an unrealistic and unnecessary schedule.

    We can build lots of nuclear plants right now (Generation III: improved design but not revolutionary). But, simultaneously, with waste to dispose of and uranium reserves being depleted (ha!), we - governments and the nuclear industry - should indeed develop these new technologies (Gen IV, thorium, traveling wave reactors etc.). These new reactors can then be built in a few decades, with "the ability to consume existing nuclear waste in the production of electricity".

    "We need to build generation IV nuclear plants to use the immense amount of energy still in the once used nuclear fuel... You must have a poor opinion of future generations if you think they will not be smart enough to use this nuclear fuel to safely produce power for generations to come."

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  5. Thorium + uranium has been used in the THTR-300 reactor in Germany. The plant ha severyl problems, was too costly and had to be shut down afte a very short operation time.

    http://en.wikipedia.org/wiki/THTR-300

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