moinsdewatt wrote:Grelinette wrote:There are some values on the internet, of the order of 300 to 400 degrees in the primary circuit, ie the circuit whose water will directly recover the heat produced by the nuclear reaction, (See the EDF website) ... while the nuclear reaction is capable of producing some 15 000 000 of degrees Celsius. (We "play" with fifteen million degrees to use 300! ).
No, there is nowhere 15 000 000 of ° C in a fission reactor.
You have not understood anything about what happens in a fission reactor. Review Wikipedia.
Sorry, I'm not an expert on the subject, and I'm waiting for this type of discussion to better understand what nuclear is, but especially, apart from the many risks and dangers known and inherent to this energy, why does this subject give rise to so many oppositions and disagreements and with as much virulence, against the background of exchanges of figures and information that are systematically questioned? ? !!!
(The debates on other sons, and on this one also, are blatant examples).
For the neophyte that I am it is very difficult to get an idea between those who say that nuclear energy is cleaner and less dangerous than others, and others who claim that the exploitation of this energy is not only more polluting and can incidentally heavily burden the future of our planet, even destroy it ... Uh, well, yes, who says the truth, who should I believe? ...
Having said that, by reading the discussions of this forum on the subject of nuclear power, discussions which obviously involve specialists, I note on the one hand that ALL the data put forward by one and the other are always systematically contradicted and subject to opposition, and on the other hand, that it is very difficult to have reliable information, even by searching the web.
Public chat Wiki I read this:
Chapter: Fusion Mechanism: ...
Very high temperature: The energies necessary for fusion remain very high, corresponding to temperatures of several tens or even hundreds of millions of degrees Celsius depending on the nature of the nuclei (see below: fusion plasmas). In the Sun, for example, the fusion of hydrogen, which results, in stages, in the production of helium takes place at temperatures of the order of fifteen million kelvin, but according to different reaction patterns of those studied for the production of fusion energy on Earth. In some more massive stars, higher temperatures allow the melting of heavier nuclei.
Certainly, I misread and the "hundreds millions of degrees Celsius" correspond to the "necessary" energies (without really knowing if this is the temperature that must be supplied to launch the reaction, or if it is that of the reaction itself) but that does not change much to my basic (naive) observation which is that "we play with millions of degrees to finally use only the few 300 ° necessary to heat the water of the primary circuit ".
Moreover, here is another thing that I do not quite understand: how can a positive global balance, in terms of energy produced and usable, if we must provide very high temperatures to finally recover very low, any proportion grade (330 °)? ...