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Saturday, January 2, 2010


There are two types of nuclear energy powerplants: fission, like the Atomic Bomb, where a special isotope of uranium and/or plutonium is used as the fuel, and fusion, the Hydrogen Bomb, where two isotopes of hydrogen are combined to produce energy. Our Sun and all stars fuse hydrogen to produce heat. The former results in radioactive wastes that can remain dangerous for many hundreds of thousands of years, while the latter still has to be stored, but only for several tens of years. Uranium/plutonium fission materials can be used by terrorists for dirty bombs, and, depending on who you ask, there is such a thing as Peak Uranium. France, for example, now only imports its nuclear fuel. There is also the fickle price of uranium, which for decades dawdled at $20/pound, only to zoom up close to $140/pound in 2007, settling more recently to $45/pound.

Remembering Hiroshima/Nagasaki, Chernobyl/Three Mile Island, in consideration of nuclear terrorism, plus the sticky problem of where to store those nuclear wastes, I have long been an opponent of fission. Until now. Cosmos in 2006 and the latest issue of Wired both cover thorium as an option for nuclear electricity. Named after the Norse God Thor, this element shows exciting potential as fuel for a next generation fission reactor.

throrium metal.jpg

There is a blog site on this subject. You can read all those links to gain in-depth knowledge, but let me give you my top ten reasons for advocating thorium, at least to promote a thorough public discussion:

  1. There are up to six times more thorium than uranium, with India having about a third of the supply in one report and Australia as #1 and the USA as #2 in resource potential in another. Some go so far as to say that there is thorium to supply all our needs for a thousand years. Clearly, the field is just beginning to be understood.
  2. The very first commercial nuclear powerplant, in 1962, was powered by thorium late in its life cycle until decommissioning, so we know the concept works.
  3. However, America at the beginning turned to uranium/plutonium because our “war” advisors wanted this fuel for nuclear weapons.
  4. For a typical 1000 MW uranium powerplant, you start with 250 tons of uranium ore. A 1000 MW thorium system uses only one ton of thorium, but it is of interest that a 1000 MW coal plant, on average, ends up with 13 tons of thorium in the remaining ashes.
  5. The fuel cost for a conventional nuclear powerplant is $50-$60 million, while the equivalent thorium reactor will only use $10,000 of thorium.
  6. Uranium/plutonium wastes need to be safely stored for hundreds of thousands of years, while thorium is not fissile, and the reactor wastes would require, perhaps, caring for several hundred years.
  7. There is no terrorism potential for the thorium cycle.
  8. There can be no nuclear meltdown for a thorium reactor.
  9. Uranium fission, thorium fission and fusion produce very little carbon dioxide (not from the process itself, but the materials and construction).
  10. Regarding the size of land required, a 1000 MW nuclear power site needs about a quarter million square feet, surrounded by a lot of nothing. A thorium 1000 MW facility would only need 2500 square feet, with no buffer zone. Am I reading this correctly? You can’t legally build a house on a lot of this size.

My book well covers nuclear power and I worked at the Lawrence Livermore National Laboratory on laser fusion. I don’t previously remember the thorium option being even discussed. Yes, it’s not perfect because you still need to mingle thorium with some rare uranium and there are assorted warts, but if global warming is real, we will immediately need viable options to replace coal, and the thorium fission reactor should as soon as possible undergo comprehensive due diligence and airing out in the public, and as soon as possible replace uranium in as many existing nuclear power facilities (yes, the retrofitting option is another bonus) as possible.


1 comment:

Kirk Sorensen said...

Very interesting Dr. Takahashi!