Sorry for the long pause in blogging, folks—the new year should see a major resurgence in posts. But here’s the latest thing on which I want to comment:
Usually when reading articles like this it’s informative to skip to the end and read the affliation of the author. In this case, his name is Peter Asmus and according to an interview in Treehugger (which has devoted a few articles to thorium), Mr. Asmus is a “renewable energy expert and author of Reaping the Wind and Reinventing Electric Utilities: Competition, Citizen Action, and Clean Power. He’s even in a band that plays energy-related songs.”
Mr. Asmus likes wind. He certainly doesn’t like nuclear, or at least, today’s implementation of nuclear technologies (i.e. U-235 burning in the light-water reactor).
First he claims that nuclear power is a violation of the free-market principles of the Republican party because of the levels of government involvement.
There is no power source less compatible with the GOP’s love of free markets and disdain for regulation and subsidy than nuclear fission. Without government intervention, there simply would be no nuclear industry.
I think government involvement in nuclear energy is unavoidable. The intense desire to develop uranium enrichment came from the Manhattan Project’s need for highly-enriched uranium, and is it any wonder that governments would tend to be very cautious about how uranium enrichment was subsequently developed? I for one am very glad that the government has “intervened” and regulated the development of nuclear energy. It is not something to be undertaken lightly or irresponsibly.
Next Mr. Asmus concedes that the operation of nuclear plants does not contribute to global climate change and that “the new pebble bed modular reactor may well leak less, greatly reduce the risks of catastrophic meltdown and use less uranium fuel.”
But he is clear to warn us that “nuclear power is far from being clean or green.”
The points of his argument:
In the nuclear fuel process, uranium enrichment depends on great amounts of electricity, most of which is provided by dirty fossil fuel plants releasing all of the traditional air pollution emissions not released by the nuclear reactor itself. Two of the nation’s most polluting coal plants, in
Ohioand , produce electricity primarily for uranium enrichment. Indiana
So let me see if I understand this. Nuclear power does not contribute to climate change, but nuclear power is far from being clean and green because uranium enrichment plants in
But the energy consumed in enrichment itself is a function of how much of the abundant natural isotopes of uranium and thorium are used to produce energy rather than the rare uranium-235 isotope. In the U235-fueled light-water-reactor, the conversion ratio is less than unity, and so more fuel is burned that converted. Overall, the reactor essentially “burns out” the U235 from the fuel, leaving mostly unburned U238, some transuranics that cause waste-disposal concerns, and fission products.
But for reactors with conversion ratios of unity or better, the picture is very different. These reactors only need fissile material like U235 to start the reactor, and thereafter produce the fuel that they need from abundant U238 or thorium. For the liquid-fluoride thorium reactor, the picture is improved considerably. It needs much less fissile material to ‘start” than other breeders and it can move bred fuel from blanket to core with considerable ease without relying on the expensive techniques needed for solid-fuel.
The takeaway message of this for Mr. Asmus is that the energy needed for enrichment is no reason to discard the use of nuclear energy.
Next, Mr. Asmus contends that nuclear power is releasing dangerous radioactive isotopes to the environment, including carbon-14, iodine-131, krypton and xenon. When I read this I had to laugh a bit.
Carbon-14 production in a conventional reactor would come about from the trace amounts of nitrogen-14 that might be present in water or fuel. Very very little N-14 is present in the reactor in the first place—probably measured in parts per million.
On the other hand, significant amounts of carbon-14 are being produced NATURALLY in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen—far more than are coming from some reactor-based source. Life has survived with carbon-14 for billions of years and seems to have made it.
Iodine-131 is a really nasty isotope. But with a half-life of 8 days, it doesn’t last too long, and it is also rather inhibited in its release, since it tends to form cesium iodide salts in uranium oxide fuel and is continuously removed in fluid fueled reactors like the LFTR. One of the surprises of the
Then xenon and krypton—these noble gases are kept within the uranium oxide fuel elements of conventional solid-core reactors, and are continuously removed in fluid-fueled reactors. Xenon’s radioactive isotopes are short-lived and decay quickly; krypton does so as well with the exception of krypton-85, which has a 10 year half life. Krypton-85 is a weak beta emitter and is not absorbed in biological processes. At any rate, krypton can be liquefied and isolated during reprocessing and is not released in any significant amount.
Mr. Asmus then goes on to say that uranium mines are like coal mines and pose a 250,000 year radiological hazard. Well, mines are mines, but when mining uranium you need to mine many orders-of-magnitude less ore than a coal mine for an equivalent amount of energy. Any radiological hazard of a uranium mine would be from the NATURAL uranium present—uranium that has been present since the formation of the Earth. At any rate, using more U238 or thorium will reduce mining requirem
ents tremendously, in the case of thorium in an LFTR, roughly 1/300th of today’s ore requirement would be needed.
Finally, Mr. Asmus plays the perennial favorite—catastropic meltdown, or the China Syndrome, stating that the catastrophic accident could kill 100,000 people. If he means this to be the nail in the coffin of “nuclear power” then I suppose he should reference his previous concession that pebble-bed reactors wouldn’t be capable of melting down. In the case of the fluoride reactor, the fuel is already melted, and a total loss of power or major sabotage would lead the freeze plug in the bottom of the reactor to melt, draining the core fluid into a passively cooled drain tank where recriticality was impossible. Even the latest generation of the light-water reactor employs many more passive safety features than previous designs.
Using the meltdown argument to dismiss nuclear power is like saying computers can’t work because vacuum tubes can break.
At any rate, read the article for yourself and decide if I’ve been too hard on him. You’ll get to enjoy nuggets like drug-fueled orgies at Californian reactors in the 1970s.
Fear, uncertainty, doubt (FUD) mixed with sexual aberration seem to be Mr. Asmus’s best arguments as to why we should ignore an energy source that can stop global warming, eliminate dependence on foreign energy sources, and provide clean power for tens of thousands of years.