OP specifically referred to breeder reactors, which this is not. This is a reprocessing plant which “scrapes” fuel like Pu (which is not that radioactive) and puts it in a normal reactor.
The nasties are all there still.
Breeders “make” their own fuel from actual waste. The US and France had reader had breeder programs, but shut them down.
Double digits of France's electricity comes from reprocessed nuclear fuel.
1. https://en.wikipedia.org/wiki/La_Hague_site