Dear Sirs:
The primary reason the Enterprise used 8 A2W reactors is that AT the TIME (late 1950's to early 1960's), those were the only proven designs available. By the time the Nimitz was designed (late 1960's to early 1970's) civilian and shipboard nuclear reactors had been scaled up to the point where only 2 were required instead of the original 8.
Another problem with the choice of the particular reactor design (PWR's - pressurized water reactors) is that it limited the conditions in the steam generators to below the critical temperature of water, thus limiting thermal efficiency and power that could be extracted.
That problem has plagued pressurized- and boiling-water reactors ever since, though there have been proposals to provide special channel within GE's boiling-water reactors (BWR's) for superheating steam, no commercial system has yet been fielded.
For China to have successfully built its own 2nd or 3rd? generation, naval propulsion reactors (for the 093 and 094 class submarines), means that it has probably achieved the technical level of the US in the 1970's or 1980's (using a lot of what they learned from the commercial power reactors they have been building).
As to the PLAN's indigenous Naval Gas Turbines, the progress made (or claimed) has been encouraging although no new-build designs use them.
In comparison, China builds many sea-going vessels using commercial diesel designs made in China.
Those vessels bring us back to Crobato's CODAD vs CODAG situation.
We can sum up the PLAN's situation like this, for extended cruising its vessels will probably need medium or high-speed diesels as the primary propulsion units, and (when this becomes possible) use gas turbines for higher power needs.
As they have not yet done this on their latest and fastest building new vessel (the 054A frigate, which given its limited displacement really needs a light power plant), we are forced to conclude that a suitable gas turbine power plant is not yet ready.
