Russia is traditionally very good with nuclear technology especially naval and miniature ones. Poisedon torpedo has a gas cooled mini reactor which if true would be very advanced and be first of it's kind, also there's that nuclear powered cruise missile. China also sourced RTGs from Russia for various space missions like Yutu rovers.
Yes maybe with specialty nuclear reactors like the ones you've mentioned but certainly not with commercial power stations anymore. Russia's active molten salt reactors where? Russia's thorium reactors where? Russia's pebble bed reactors where? On all three China's got more experimental and commercially active ones now today operating. Russia has very limited experimental ones in the past or planning to build.
For conventional reactors China has caught up. Studied its own, Soviet ones, American ones, French ones for decades and the latest Hualong gen 3s are no less than the latest Russian VVERs. Russia isn't even ahead of China in commercial nuclear energy. Specialty cases the Americans are a match if not better than the Russian ones. They also have miniature reactors and a long history of building proven ones.