Last login: Monday, May 21, 2012
Nuclear power isn’t the problem.
The problem is with the reactors the world has been using to make it. If the reactors at Fukushima had been Liquid Fluoride Thorium Reactors (LFTRs) they wouldn’t have a mess on their hands.
Liquid-fuel reactor technology was developed at Oak Ridge National Labs in the 1960s. Although the test reactor worked flawlessly for over 20,000 hours, the project was shelved, a victim of political shenanigans during the Nixon Administration.
A LFTR is a completely different kind of reactor, as different as an electric motor from a gasoline engine. It can’t melt down, and it automatically adjusts its heat generation to meet changing workload demands. It requires no active cooling system and can be installed anywhere on earth, even an underground vault. A tsunami or a tornado would roll right over it, like a truck over a manhole cover.
LFTRs use liquid fuel ⎯- nuclear material dissolved in molten fluoride salt. Solid-fuel reactors are atomic pressure cookers, with the constant danger of high-pressure ruptures, meltdowns, and the forceful ejection of radioactive material into the environment. LFTRs don’t use any water or steam, and they always operate at ambient pressure.
If disaster strikes and a LFTR springs a leak, the spill cools to an inert lump of rock, chemically locking all the nuclear material inside. The fuel can all be recovered and used again. The spill would be measured in square meters, not square kilometers.
LFTRs can deliver 750ºC heat for industrial processes, or spin a high-temperature gas turbine to generate power. They run on Thorium, a mildly radioactive material more common than tin and found all over the world. America has already mined enough Thorium to power the entire country for 400 years. It’s found by the ton in the tailings of our abandoned Rare Earth Element mines.
LFTRs are highly resistant to proliferation. Thorium is bred into 233Uranium inside the reactor, but only enough is made to keep the LFTR running, so no stockpiling occurs. While 233U is an excellent fuel, its harsh radiation makes it nearly impossible to steal, and extremely difficult to use in a weapon.
Liquid fuel can be continuously cleaned of the contaminants that spoil solid fuel. This unique feature enables LFTRs to consume their fuel so thoroughly that they can even use the spent fuel from other reactors, cleaning up our legacy of nuclear waste while producing a minuscule amount of waste themselves.
A 1-gigawatt LFTR, big enough to power a city of one million, will run on one ton of Thorium per year, or about 2 teaspoons per hour. The LFTR’s yearly long-term waste will be the size of a basketball. Compared to the long-term waste of a solid-fuel reactor, a LFTR’s waste would be substantially harmless in just 300 years. Not 300 centuries -- 300 years.
Google: LFTR, liquid fluoride thorium reactor, MSR, molten salt reactor, Thorium energy
See the Wired.Com article “Uranium Is So Last Century"
May 21, 2012 at 8:02 a.m.
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