NukeWorker Forum
News and Discussions => Nuke News => Topic started by: Rennhack on Sep 15, 2010, 12:24
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This is old news, but it is new to me. I figure it will give us something to talk about other than Navy Nukes, PoliSci, or Karma for 5 min.
http://nextbigfuture.com/2009/06/supercritical-co2-recompression-cycle.html
http://nuclear.inl.gov/deliverables/docs/interim_report_300mwe_s_co2.pdf
http://www.ne.anl.gov/facilities/co2loop/
http://dspace.mit.edu/bitstream/handle/1721.1/17746/56504009.pdf
Skinny: This high performance design achieves a thermal efficiency approaching 53%, which yields additional cost savings. [Current nuclear reactors are at about 35% thermal efficiency, and some newer designs will have 40-45%]
And the supercritical CO2 turbines are tiny:
(http://1.bp.blogspot.com/_VyTCyizqrHs/Sju-cwEEgHI/AAAAAAAAEEE/fW7IWZSUKlg/s400/SCO2sizeComp.gif)
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This passes the OOOHHH-AAAHHH test but, other considerations are not discussed. :)
Fuel cycle and waste management (what are the isotopic and radiological dynamics?) and reactor design are not discussed (550C and using U233 or Thorium). I would like to see a workable prototype first. Otherwise the design reminds me of an HTGR without a moderator/reflector (the proposed size is so small that neutron propagation will leak out). The neutron cross section of CO2 has to be incredibly small. :o
Using Thorium would lend to a fast flux reactor (neutron embrittlement anyone). The compressor and generator are sealed into the vessel housing. Synthetic lubricating products tend to break down rapidly in a high flux environment. Looks good on paper and you can build a nice model but the starship Enterprise is a long way from her first voyage.
And, the best for last, sell the name "Supercritical" CO2 gas reactor to the NIMBYs. They would have a cow and a media field day with the name and the process. :D
As for the design, its like new cars vs old cars. I can rebuild a carburetor or engine, gap plugs, and change out points and condensers but I sure as hell cannot figure out the new sensor and computer technology of today's cars. ???
Nice discussion but will anyone byte? :P
BA 8) 8) 8)
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Except that this super-small red gizmo hasn't been prototyped and proven, it's only theory. One could also do a theory run using a Tesla turbine and selected triple-point fluids and come up with good numbers.
From the nextbigfuture text:
The basic design achieves 45.3 % thermal efficiency and reduces the cost of the power plant by ~ 18% compared to a conventional Rankine steam cycle. The capital cost of the basic design compared to a helium Brayton cycle is about the same, but the supercritical COB2B cycle operates at significantly lower temperature. (In a reactor, that CO2 will undergo neutron activation much more than helium) The thermal efficiency of the advanced design is close to 50% and the reactor system with the direct supercritical COB2B cycle is ~ 24% less expensive than the steam indirect cycle and 7% less expensive than a helium direct Brayton cycle. It is expected in the future that high temperature materials will become available and a high performance design with turbine inlet temperatures of 700P o PC will be possible. This high performance design achieves a thermal efficiency approaching 53%, which yields additional cost savings. [Current nuclear reactors are at about 35% thermal efficiency, and some newer designs will have 40-45%] emphasis by Dave
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Using geologically deposited thermocouples has also been proposed (geothermal energy). Safe and green. Why not use that?
BA 8) 8) 8)