Be a pity if it had to burn coal or heavy grade oil to keep it fired. Think of the carbon footprint....
Not that the Chinese military would give a flying whatever how big that carbon footprint might be. They do not have to answer to any “environmentalists”.
But nuclear power would certainly give them great leverage in patrolling the ocean, being unnecessary to refuel for years at a time, and fuel storage would be relatively compact. The used rods? Dump them overboard.
Or maybe they will go to a thoroughly modern molten-salt thorium reactor, which has a MUCH smaller nuclear waste product. And is completely practical as a power plant.
I have a hunch that they are not nuclear powered. That puts them at a strategic disadvantage. Destroy their oilers and they become stationary floating targets.