# How to separate isotopes of Plutonium?

In case of Uranium, things are lot easier, because $UF_6$ is gaseous from around 60 $\,^{\circ}\mathrm{C}$.

I know, that in most cases, plutonium isotope separation is not needed, because there is no need to separate its fissile isotopes. But there is an exception: radioisotope thermoelectric generators (used to power remote devices such as spacecraft and unmanned polar equipment) need ${^{238}}Pu$.

I think, Plutonium can be separated from the depleted fuel cells with chemical methods, but how to separate ${^{238}}Pu$ from the result?

• Laser isotope separation (AVLIS/MLIS/SILEX/CRISLA/CHEMLIS). – Deer Hunter Mar 17 '15 at 10:11
• @DeerHunter Thank you! I checked $PuF_6$, and it is also gaseous from 60 C. But I don't know if it is really used. Probably a big disadvantage that it is much more radioactive, there are many isotopes (between 238 and 242), and in the most "interesting" case there is only a single difference in the nucleon number (238 vs. 239). Afaik, in most cases they try to avoid the Pu isotope separation if they can (for example, the ratio of the $Pu_{240}$ weapon-grade Pu is limited by the removing of the fuel cells early, instead of create much more Pu, but with more $Pu_{240}$). – peterh Mar 17 '15 at 12:49