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Advanced nuclear technology and CO2 mittigation

Wednesday, May 20, 2009

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Large scale production of post-carbon energy technology is a key to CO2. The post-carbon technology must must be producible in sufficiently large numbers to have a significant impact on of CO2 emissions, yet have low capital and operation costs. If capital costs foe a carbon replacement technology can be paid for our of fuel cost savings and other efficiencies, so much the chances of successful GHG mitigation will be greatly improved.

Massive deployment of post carbon energy technology would almost certainly mean reliance on commodity materials such as stainless steel, and cement. A really desirable post carbon technology would contribute those those processes which produce raw materials needed for its own production. Thus it would be highly desirable for a post carbon energy technology to contribute the heat needed to produce steel and cement, either directly or through providing heat input into a chemical process by which high temperature fuel is produced.Thus if a reactor provides the heat needed to produce hydrogen gas, and burning the hydrogen provides the heat needed to make cement, the nuclear technology may be self sustaining, in a way which renewable technologies is not.Consider the issue of a material like neodymium in LFTR generators. What might prove interesting about this pairing is the potential of the LFTR to produce neodymium. Neodymium is a fission product, and LFTRs would produce about 150 pounds of neodymium for every billion watt years of electricity they produce. This is the essence of green technology, the ability of a technology to produce the resources required to impliment the technology on a massive scale.

Windmills can’t do that. Windmill designers might choose to use neodymium in their generators, but they can never produce neodymium from the normal operation of their windmills. If neodymium has to be used in the manufacture of windmills, it has to be dug up from the earth. From the viewpoint of the production of scarce raw materials, the LFTR is simply “greener” that the windmill. From the viewpoint of Energy returned from Energy Invested the LFTR wins over the windmills hands down.From the viewpoint of carbon emissions per kWh of electricity generated, the LFTR wins over the windmill hands down.

Meier calculated that in 1998 conventional nuclear generated one GWhe for every 18 tons of CO2 emitted. Wind generated 14 tons of CO2.http://fti.neep.wisc.edu/pdf/fdm1181.pdf

Technological options played a very large role in the calculated CO2 emissions for nuclear.Were the analysis to focus on alternative nuclear technologies like the LFTR, the IFR, or the Indian FBR. the comparison between nuclear and wind would greatly favor the advanced nuclear technology.For example in American conventional reactors 3/4^th of the associated CO2 emissions were from coal fired power plants that supplied electricity to uranium enrichment facilities.Thorium does not require enrichment. Hence the switch to a thorium fuel cycle produces a 75% decrease in CO2 emissions from the Uranium fuel cycle. Thorium is already mined at uranium mines, rare earth mines, and phosphate mines. Hence no added emission of CO2 would be produced in order to mine thorium. This produces a further reduction of CO2 emissions related to mining thorium. Thorium can be prepared for use in reactors using low cost, low CO2 emission fluoride chemical processes. Thus the CO2 emissions of of a LFTR would easily be 10% of those from a conventional nuclear plant ca. 1998.

Now the LFTR uses mined nuclear fuel form 200 to 300 times more efficiently than a conventional nuclear power plant. Thus the CO2 emissions of a LFTR in producing electrical energy is perhaps 0.05% of the indexed conventional nuclear power plant. This would give us a figure of about 18 pounds of CO2 per gWhe. Quite obviously the LFTR and other Generation IV breeders far outperforms the windmills as a carbon mitigation measure.