Safe, Sustainable, Nuclear Power

[xoxoxoBruce]

LFTRs, Liquid Fluoride Thorium Reactors are the way to go. 5000 tons of thorium could replace all the oil, coal, and natural gas we burn to make power, for a year.

[tw]

Originally Posted by xoxoxoBruce

LFTRs, Liquid Fluoride Thorium Reactors are the way to go. 5000 tons of thorium could replace all the oil, coal, and natural gas we burn to make power, for a year.

Original plans to make that possible also discussed the shortage of nuclides to support what could have been a fleet of 500 reactors. That is why fast breeder reactors were considered essential. Problem is that nobody has been able to make one work reliably. Fermi 1 is an example of a near nuclear meltdown that almost took out either Chicago or Detriot. Clinch River was a next US attempt that (for reasons I never did learn) was scrapped. Japanese currently have a monoply on much of the world's plutonium in what was hoped to be a new attempt at a fast breeder.

Thorium Uranium is simply another of many experimental reactors that have been considered. Current technology for light water reactors is Uranium Plutonium fuel cycles. Obviously, plutonium creates major human safety problems.

[xoxoxoBruce]

Existing reactors use uranium or plutonium—the stuff of bombs. Uranium reactors need the same fuel-enrichment technology that bomb-makers employ, and can thus give cover for clandestine weapons programmes. Plutonium is made from unenriched uranium in reactors whose purpose can easily be switched to bomb-making. Thorium, though, is hard to turn into a bomb; not impossible, but sufficiently uninviting a prospect that America axed thorium research in the 1970s. It is also three or four times as abundant as uranium. In a world where nuclear energy was a primary goal of research, rather than a military spin-off, it would certainly look worthy of investigation. And it is, indeed, being investigated.

India has abundant thorium reserves, and the country’s nuclear-power programme, which is intended, eventually, to supply a quarter of the country’s electricity (up from 3% at the moment), plans to use these for fuel. This will take time. The Indira Gandhi Centre for Atomic Research already runs a small research reactor in Kalpakkam, Tamil Nadu, and the Bhabha Atomic Research Centre in Mumbai plans to follow this up with a thorium-powered heavy-water reactor that will, it hopes, be ready early next decade.

China’s thorium programme looks bigger. The Chinese Academy of Sciences claims the country now has “the world’s largest national effort on thorium”, employing a team of 430 scientists and engineers, a number planned to rise to 750 by 2015. This team, moreover, is headed by Jiang Mianheng, an engineering graduate of Drexel University in the United States who is the son of China’s former leader, Jiang Zemin (himself an engineer). Some may question whether Mr Jiang got his job strictly on merit. His appointment, though, does suggest the project has political clout. The team plan to fire up a prototype thorium reactor in 2015. Like India’s, this will use solid fuel. But by 2017 the Shanghai Institute of Applied Physics expects to have one that uses a trickier but better fuel, molten thorium fluoride.
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One or two 233U bombs were tested in the Nevada desert during the 1950s and, perhaps ominously, another was detonated by India in the late 1990s. But if the American experience is anything to go by, such bombs are temperamental and susceptible to premature detonation because the intense gamma radiation 233U produces fries the triggering circuitry and makes handling the weapons hazardous. The American effort was abandoned after the Nevada tests.
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Extracting, smelting and machining material containing even trace amounts of it is beyond the scope of all but a handful of national weapons laboratories. Rogue nations interested in an atom bomb are thus likely to leave thorium reactors well alone when there is so much poorly policed plutonium scattered around the world. So a technology abandoned because it could not be turned into weapons may now, in part for that very reason, be about to resurface.

So sayeth The Economist.