Saturday, June 6, 2015

More Thorium Silliness

Just a few thoughts that came to mind while reading comments on WUWT, the latest puff-piece on Thorium-based nuclear power plants. 

First, very few commenters have a grasp of what a molten salt is or does, especially when that molten salt contains radioactive thorium and uranium and other fission products.  

One comment, in particular, shows a vast ignorance of economics. claiming ". . . near-free (sic) and unlimited electrical power ($0.03/kWh), which will gut the remaining industrial sectors of Western economies. . ."  This refers to thorium-powered nuclear plants built in China.   The 3 cents per kWh might be the fuel and variable operating cost, but certainly does not include amortized capital costs.  As shown previously on SLB, a molten-salt reactor using liquid fluoride salts will cost much more than the present generation of uranium-powered pressurized-water reactors, and those cost approximately $10,000 per MW or more.  The per-kWh cost just for the capital cost would be approximately 25 cents, depending on how much state subsidy is applied to the capital cost.    Note: apparently "forgetting" to include the capital costs is a favorite ploy of nuclear proponents, because it allows them to compare (barely favorably) a nuclear plant's "cost" to natural gas.  

Another clueless commenter states ". . . there isn’t really much for the CHinese (sic) to do except size up the design. . . "  This particular commenter claims to be ". . .a design engineer who worked on projects for nearly 40 years. . ."   The "size up the design" refers to scale-up of a thorium molten salt reactor.   As I wrote elsewhere on SLB, scale-up from the pilot plant size at Oak Ridge to a full-scale commercial plant of 1,000 MW electrical output is a massive, daunting task.  (see link)  In pertinent part: "Scale-up from ORNL size (7 MW thermal) by 500 times is an enormous challenge.   Note that scale-up with a factor of 7 to 1 is a stretch, yet such a factor (using 6) requires four steps (40, 250, 1500, and 3500) to use round numbers.   Each larger plant requires years to design, construct, and test before moving to the next size, and that is if the larger design actually works the first time."  

The same clueless commenter on scale-up added to his list of errors with this:  ". . .corrosion problems that some rag on about . . . were all but solved. . ."   This refers to the very real corrosion and cracking in the reactor material, in fact, any material that touched the hot molten radioactive fluoride salt.  A material was developed and tested, but not for the 40 or more years with multiple heating-up and cool-down cycles that a commercial reactor must withstand, not to mention any vibrational stresses caused by any earthquakes.   The Oak Ridge National Laboratory "developed (in 1977) an improved and very expensive alloy Hastelloy N for nuclear applications with molten Fluoride salts.   In tests, Hastelloy N with Niobium (Nb) had much better corrosion resistance to molten fluoride salts."  (source: link just above from SLB article on thorium molten salt reactors).  

There are many other, equally silly comments. 

Roger E. Sowell, Esq. 

Marina del Rey, California
copyright (C) 2015 by Roger Sowell

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