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It seems that uranium based fission seems to have inherent safety problems associated with it's management:

  • leaks of fuel and waste
  • natural forces destabilising reactors
  • threat of terrorism

In addition, there seems to be an energy crisis on the horizon as our ability to extract fossil fuels diminishes (as well as the now undisputed climate change effect of CO2 et al.).

So, is there an alternative form of nuclear fission that can be rapidly scaled up to replace existing power station technology that does not present such dangers?

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Is this a skeptic question? Seems like it would be a better fit for physics.stackexchange.com to me... – BlueRaja - Danny Pflughoeft Apr 21 '11 at 6:33
Not on topic, it's not about a claim. – Sklivvz Jan 28 '12 at 12:32

closed as off topic by Sklivvz Jan 28 '12 at 12:31

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1 Answer

up vote 8 down vote accepted

One potential way forward is Thorium. A quick breakdown of the salient points:

  1. Weapons-grade fissionable material (uranium233) is harder to retrieve safely and clandestinely from the thorium reactor than plutonium is from the uranium breeder reactor.
  2. Thorium produces 10 to 10,000 times less long-lived radioactive waste than uranium or plutonium reactors.
  3. 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 U235.
  4. Because thorium does not sustain chain reaction, fission stops by default if we stop priming it, and a runaway chain reaction accident is improbable.

Another arcticle on Thorium is available here that highlights its efficiency as a fuel.

The energy differential from this efficiency has been demonstrated to be anywhere from 60% to 200% greater. It should also be noted that because thorium fuel does not require enrichment, whereas uranium fuel does, much less raw material is required. In order to produce one year’s worth of fuel for an average reactor (the US average reactor capacity is 1,000 Megawatts of electricity (MW), approximately 550,000 pounds of natural uranium is required. Seven-eighths of this material has the 235-uranium extracted out of it, leaving unusable depleted uranium waste behind. Because thorium does not require enrichment, only one-eighth, or 69,000 pounds of raw material is required for the same energy output. However, there is not even an equivalent energy output because of thorium’s enhanced neutron economy and enhanced fissionability characteristics. Therefore, this 69,000 pounds, a full one-eighth of the material required for standard fuel will generate 60% to 200% more energy output.

A quote to highlight how little use it would be to a terrorist (My emphasis):

The waste profile of the thorium fuel cycle is a vast improvement. The vast majority of the waste is the 233-uranium isotope. 233U can be reprocessed to be used as fuel in a closed thorium fuel cycle, however the technology for this is not yet available. In the meantime, 233U cannot be used to make bomb material because of its natural properties. Specifically, it is because 233U contains 232uranium isotopic content, whose decay products give off significant gamma rays, that would fry the electronics in any conceivable bomb mechanism not to mention being fatal for any human being within several meters, making transport of weapons impossible. Moreover, these gamma rays would be immediately detectable by the most basic satellite surveillance. Bomb fabrication from 233U, though technically possible, is so impractical that it is considered impossible. Minor actinide waste in the thorium fuel cycle is reduced by as much as 99.99% in some models.

Generally any modern nuclear reactors should be much safer than any of the reactors that have been involved in accidents as those reactors were using 40 year old technology and we have come a long way since then (even so the majority of funding these days appears to be biased towards "green sources" that are not nuclear). That being said the safety record of nuclear power reactors is not exactly bad with estimates of casualties caused by accidents such as chernobyl greatly overestimated.

I would very much like to see what a Thorium reactor packed with the latest technology could do, I think a lot of people may be very surprised by its level of safety and efficiency.

*(I should mention that the saftery record link to http://www.world-nuclear.org is likely to be biased towards a pro-nuclear stance)

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+1 for an excellent answer. Here is an interesting corroboration of the thorium approach (you may wish to read around the site as there is a lot of information there on a wide variety of energy sources): inference.phy.cam.ac.uk/withouthotair/c24/page_166.shtml – Gary Rowe Apr 20 '11 at 13:14
just a few weeks before Fukushima China announced a Thorium reactor project – Oliver_C Apr 20 '11 at 15:42
Useful additional information about Thorium reactors: europac.net/voices/why_not_thorium – Gary Rowe Feb 16 '12 at 11:14

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