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leading proponent for liquid-fluoride thorium reactor technology, to discuss the growing thorium movement around the globe. Kirk notes that thorium has 10,000 times more energy density than coal, as well as providing growing applications in the medical field. The Chinese are clearly the leaders in developing thorium reactors, with the United Kingdom looking at the potential of thorium to replace coal as a domestic energy source. The US invented the technology, but is not among the global leaders in thorium reactor development.

Kirk Sorensen has been studying thorium technology since 2000 and has been a public advocate for its use and development since 2006. He started the weblog, Energy from Thorium, which has spawned a global movement of interest in liquid-fluoride thorium reactor technology.

paul m wrote:What is Thorium,who has it,how much is there?

Don't believe the spin on thorium being a ‘greener’ nuclear option

[snip]

China did announce this year that it intended to develop a thorium MSR, but nuclear radiologist Peter Karamoskos, of the International Campaign to Abolish Nuclear Weapons (ICAN), says the world shouldn’t hold its breath.

‘Without exception, [thorium reactors] have never been commercially viable, nor do any of the intended new designs even remotely seem to be viable. Like all nuclear power production they rely on extensive taxpayer subsidies; the only difference is that with thorium and other breeder reactors these are of an order of magnitude greater, which is why no government has ever continued their funding.’

China’s development will persist until it experiences the ongoing major technical hurdles the rest of the nuclear club have discovered, he says.

But even were its commercial viability established, given 2010’s soaring greenhouse gas levels, thorium is one magic bullet that is years off target. Those who support renewables say they will have come so far in cost and efficiency terms by the time the technology is perfected and upscaled that thorium reactors will already be uneconomic. Indeed, if renewables had a fraction of nuclear’s current subsidies they could already be light years ahead. 



Extra radioactive waste

All other issues aside, thorium is still nuclear energy, say environmentalists, its reactors disgorging the same toxic byproducts and fissile waste with the same millennial half-lives. Oliver Tickell, author of Kyoto2, says the fission materials produced from thorium are of a different spectrum to those from uranium-235, but ‘include many dangerous-to-health alpha and beta emitters’.

Tickell says thorium reactors would not reduce the volume of waste from uranium reactors. ‘It will create a whole new volume of radioactive waste, on top of the waste from uranium reactors. Looked at in these terms, it’s a way of multiplying the volume of radioactive waste humanity can create several times over.’

biffvernon wrote:Yes but one of the little problems with thorium is that the details of the technology have not been invented yet.

The devil is always in the details.

Results

The broadest and perhaps most important conclusion from the MSRE experience was that a molten salt fueled reactor concept was viable. It ran for considerable periods of time, yielding valuable information, and maintenance was accomplished safely and without excessive delay.

The MSRE confirmed expectations and predictions.[13] For example, it was demonstrated that: the fuel salt was immune to radiation damage, the graphite was not attacked by the fuel salt, and the corrosion of Hastelloy-N was negligible. Noble gases were stripped from the fuel salt by a spray system, reducing the 135Xe poisoning by a factor of about 6. The bulk of the fission product elements remained stable in the salt. Additions of uranium and plutonium to the salt during operation were quick and uneventful, and recovery of uranium by fluorination was efficient. The neutronics, including critical loading, reactivity coefficients, dynamics, and long-term reactivity changes, agreed with prior calculations.

In other areas, the operation resulted in improved data or reduced uncertainties. The 233U capture-to-fission ratio in a typical MSR neutron spectrum is an example of basic data that was improved. The effect of fissioning on the redox potential of the fuel salt was resolved. The deposition of some elements (“noble metals”) was expected, but the MSRE provided quantitative data on relative deposition on graphite, metal, and liquid-gas interfaces. Heat transfer coefficients measured in the MSRE agreed with conventional design calculations and did not change over the life of the reactor. Limiting oxygen in the salt proved effective, and the tendency of fission products to be dispersed from contaminated equipment during maintenance was low.

Operation of the MSRE provided insights into the problem of tritium in a molten-salt reactor. It was observed that about 6–10% of the calculated 54 Ci/day (2.0 TBq) production diffused out of the fuel system into the containment cell atmosphere and another 6–10% reached the air through the heat removal system.[16] The fact that these fractions were not higher indicated that something partially negated the transfer of tritium through hot metals.

One unexpected finding was shallow, inter-granular cracking in all metal surfaces exposed to the fuel salt. The cause of the embrittlement was tellurium - a fission product generated in the fuel. This was first noted in the specimens that were removed from the core at intervals during the reactor operation. Post-operation examination of pieces of a control-rod thimble, heat-exchanger tubes, and pump bowl parts revealed the ubiquity of the cracking and emphasized its importance to the MSR concept. The crack growth was rapid enough to become a problem over the planned thirty-year life of a follow-on thorium breeder reactor. This cracking could be reduced by adding small amounts of niobium to the Hastelloy-N.[17]

Will they be sorted before the peak-oil induced end of civilisation? No.

An excellent article and probably about the most promising alternative energy source that exists today. Failing the development of controlled nuclear fusion, thorium breeder reactors would appear to be almost as good in terms of fuel security and environmental impact. Unfortunately, the more useful an energy source is, the more that it permits the exploitation of other resources and thus damage to the environment. That is after all, exactly what harnessed energy sources are intended to do.

This discussion brings us back to the problem that we live within perpetual growth machine, on a finite land space, with finite material and biological resources. We therefore face the problem that giving human beings a fantastic new energy source, would allow growth based economic systems to reap even more damage on the planet. This is a fundamental problem with any living system that grows within a finite environment. It can either choose to reach a stable state, or it can continue to grow until every resource is consumed and die off like bacteria in petri dish. Unfortunately, a cooperative Power Down or species-wide self-limitation would appear to be impossible in the present global political environment. The only way out of this paradox is for humanity to collectively agree to reduce population size (as China has taken steps towards achieving) and allow continued per capita economic growth. This would allow individual living standards to expand even as total GDP remained static. Gradual progression of technology, the development of compact agricultural systems, car-free cities, integrated waste management, etc, would allow environmental impact to gradually decline. Such a development would require the leadership of a body like the UN.

UndercoverElephant wrote:Beria,

As that OilDrum article points out, unless we accept that there are physical limits to growth, this sort of technology just delays the inevitable, and maybe even makes things worse in the long run. There is also going to have to be some sort of major political change to remove the power of the banks and the corporations. The whole strategy still has to change. This mustn't be seen as a means of preserving BAU.

The energy crisis is just one part of a general resources/population/cultural crisis.

UE