Is Pu Impossible to Mine in Nature Due to Its Short Half-Life?

[jimmyy]

Is it correct that Pu cannot be found in nature?
What I mean acctually is that while Uranium can be mined, Pu from what I have searchd on wikipedia cannot be mined.

I know that Pu is produced in nuclear reactors(or other facilities) from Uranium.

 

[humanino]

I know that Pu is produced in nuclear reactors(or other facilities) from Uranium.

The question is difficult to answer, because there are plenty of "natural" reactor out there. So yes, you can find Pu which has not been produced by a human reaction.

 

[Dadface]

I think humanino is probably right but it hasn't been discovered yet and I would assume that there are only tiny quantities of it.

 

[Astronuc]

Oklo: Natural Nuclear Reactors
http://www.ocrwm.doe.gov/factsheets/doeymp0010.shtml
http://www.ans.org/pi/np/oklo/

There are very few 'natural reactors' or deposits of U ores that went critical. Natural U is about 99.3% U-238 and ~0.7% U-235. But the U oxide content of U-bearing ores is very low - at most a few %.

The half-lives of the fissile or fissionable Pu-isotopes are relatively short, so if they do form by neutron capture in U-238 (with subsequent beta decay U-239 -> Np-239 -> Pu-239), there will be very little Pu remaining after millions or billions of years, i.e. trace quantities (ppm levels) that would not be economical to mine.

Pu 239, T_1/2 = 24110 y
Pu 240, T_1/2 = 6561 y
Pu 241, T_1/2 = 14.29 y
Pu 242, T_1/2 = 3.75E+5 y

U 238, T_1/2 = 4.468E9 y