From reading other stuff it seems much more likely that its a nuclear powered satellite jammer, not a nuclear satellite weapon. Nuclear powered would allow it to more effectively jam for longer distances/periods of time. We all have nuclear powered satellites in orbit which breaks no nuclear treaties so it sounds like they’re being intentionally vague for some russia fearmongering.

Not to say it’s not bad tho - it could take out commercial satellites like starlink very effectively and we know how critical that’s been for Ukraine/would be for Taiwan