Several weeks ago Joshua Pearce at Clarion University in Pennsylvania released a study titled “ Thermodynamic limitations to nuclear energy deployment as a greenhouse gas mitigation technology .” In the study he stated... nuclear energy production would have to increase by 10.5% per year from 2010 to 2050 to both replace fossil-fuel-energy use and meet the future energy demands. This line, of course, made the headlines and has been picked up by several outlets and blogs . When looking into his calculations for this statement, he made one assumption error that overstated the above sentence by nearly a factor of three. Page 121, Section 4.1 of the study states: Richard Smalley pointed out that in 2004, the global economy consumed the equivalent of 220 million barrels of oil per day, which converted into electricity terms is the equivalent of 14.5 TeraWatts (TW), or 14,500,000 MegaWatts (MW) (2005). … With a nuclear plant having about 1000 MW (1 GW) of capacity, we would need 14,500...
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In order for ... U-235 to work, a sample of uranium must be enriched ...
... To build a nuclear reactor, what you need is some mildly enriched uranium.
That's wrong both times he says it: heavy water reactors run on unenriched uranium, as do Magnox ones.
Typically, the uranium is formed into pellets
Just plain uranium? Not uranium oxide?
... The bundles are then typically submerged in water inside a pressure vessel. The water acts as a coolant. In order for the reactor to work, the bundle, submerged in water, must be slightly supercritical. That means that, left to its own devices, the uranium would eventually overheat and melt.
Does the water act only as a coolant? Does increasingly hot uranium -- oxide -- not become less reactive, and therefore "typically" level off its own fission rate, and with that, its temperature, well short of melting?
The author was informed of these difficulties shortly after May 26, 2006, that I know of, but the page hasn't changed since then, and apparently not since 2000.
One can do better here. The same enrichment-is-necessary error was present, but the author corrected it when I complained.
I think one can do better still; maybe I'll get around to taking a shot at it someday. (Aren't there better primer pages than either of these, already?)
--- G. R. L. Cowan, former hydrogen fan
Boron: internal combustion without exhaust gas