While I am not an expert on this, I know that breeding plutonium still requires separation processes to get the plutonium out from the U-238 and the fission products that will be produced by bombarding u-238 and plutonium with neutrons. If you have that level of technology, it is probably just as easy to build a conventional reactor, as the North Koreans did. The main problem is getting hold of the uranium, whihc is in fact fairly tightly controlled and could be much more so in a post-iffsion society, and the separation technology(more than one Pu isotope is produced as well.). So again, controlling those things, which will be uneeded for peaceful purposes becomes much easier with FF.
