alt.energy.renewable

"T. Keating" ha scritto nel messaggio
news:0ahrq39qlc10hik2rq6749qktogddslio6@4ax.com...
> On Thu, 07 Feb 2008 20:27:51 GMT, "Alex Chiani"
> wrote:
>
>>"Roland Mösl" ha scritto nel messaggio
>>news:81b96$47ab0b3c$557fe946$17995@news.inode.at...
>>> schrieb im Newsbeitrag
>>> news:88a7caa1-189a-4615-9f49-e0005cda51ff@v17g2000hsa.googlegroups.com...
>>>> Common perceptions of nuclear energy are full of inaccuracies.
>>>>
>>>> 1) Even older "second generation" nuclear power plants produce 93
>>>> times more energy than they consume over their lifespan
>>>
>>> And where is the energy to mine the uranium?
>>>
>>> At 0,2% it's expected that mining costs as much energy
>>> as the found uranium produces
>>
>>
>>Actually, Rossing mine in Namibia with an ore grade of only 0,035%
>>produces
>>uranium with a return of energy invested in mining 500 times lower than
>>electricity that uranium produces in a once through fuel cycle (about
>>45,000/55,000 kWh per kg of natural uranium)
>
> Err.. The Nambi mine starts out with an ore grade in the 400 to 600
> ppm range.. (Currently this is consider low grade ore)..P.S.. There
> ain't no such thing as a perfect extraction process..
>
> Despite it's ranking a slow grade ore.. it is still a finite resource
> which will be depleted @ current consumption levels.


Agree, but it' s not what I' ve said, of course uranium reserves are finite
on the planet, this is not my point. My response to Roland ( " at 0,2% it's
expected that mining costs as much energy as the found uranium produces " )
is
that even a very low grade like Rossing (0,035%) is not energy or oil
intensive at all as he believes, instead the uranium mined produces hundreds
times (more than 500) more electricity the energy the mining needs. Of
course
it's true that uranium mining requires some oil consumption, although I
suspect that coal extraction is even worst, but clearly the energy return is
enormous

Overall, even without thorium and fast breeders, uranium resources (not only
at Rossing, of course) are adeguate for a large expansion of nuclear
reactors worldwilde. Bear in mind that current uranium "spot" price is less
than 2 $ per barrel of oil equivalent, so there are large reserves of the
fuel
simply at slightly higher costs of extraction (and with a large positive
energy return), totally irrelevant in nuclear
electric kWh costs

http://nuclearinfo.net/Nuclearpower/UraniuamDistribution