Hi, the nuclear fuel reprocessing should return a 10% plutonium-239 according to the recipe.
I've had this process running for a few hours... now at 155 used-up uranium fuel cell and still never produced any plutonium-239... Am I missing something?

That doesn't sound right... it's also something controlled by the game engine, not the mod.
10% means that there's a 10% chance that when the recipe completes, you'll get one of these items. It's also a CHANCE, which means, getting one is like rolling a 10 sided dice, and only getting one if you get a 10 showing, which means it is possible you've just been really unlucky and haven't scored a 10 yet.

Also... don't just look at the statistics... I've been made aware of an issue where, because some of my materials are listed as Catalysts, they might not show up on the productions screen. Actually check the machine to see if it made any Plutonium.

Hi bob, thanks for the response... As I was typing my answer, I finally got a plutonium out of the centrifuge. It took 195 used-up fuel cells, so it was indeed a streak of bad luck I guess? Now I need 39 more :D

Btw, I can confirm that the plutonium actually showed up in the production tab. Anyway case closed! Thanks.