Feasibility of fission reactor at centre of Earth

[verdigris]

There's a a paper by J Marvin Herndon about the feasibility of a fission reactor about 5 miles wide at the centre of the Earth,which could generate the geomagnetic field.Someone said in New Scientist magazine that because gravitational forces are nearly zero at the Earth's centre then the heavy chemicals mentioned by Hearndon wouldn't separate out on the basis of density as he suggests.

http://www.understandearth.com/Herndon%20JGG93.pdf

 

[Andre]

Quite right indeed. Moreover the inner core is solid under the extreme pressure. However, all the unstable isotopes anywhere within the Earth, perhaps most abundantly 40K just continue their usual radioactivity and thus generate heat. Some think that this process is the main cause of the heat of the core after initial cooling.

Others have other ideas of course.

qhttp://nujournal.net/core.pdf[/URL]
Just showing it for educational purposes, how far one can go scaremongering in order to get into the limelight.

 

[verdigris]

Andre said:
"the inner core is solid under the extreme pressure. "

Solid lumps of uranium do naturally undergo fission such as those found in 1972 in a mine at Oklo, Gabon.But the neutrons need to be slowed down (at Oklo water was the moderating material).There are many elements that can act as moderators - carbon is one.Also the core of the Earth does not have to be solid if the core temperature is high enough.Some moderating materials have atoms displaced by neutrons and these atoms stay in the moderating material with high potential energy that can suddenly be released by a temperature rise(Wigner energy that caused the fire at Windscale).

 

[billiards]

Andre said:
Also the core of the Earth does not have to be solid if the core temperature is high enough.

The inner core is solid because s-waves travel through; the p-wave loses energy in the form of an s-wave at the liquid/solid, outer/inner core boundary. This happens because p and so-called sv- waves form a coupled system.