The alleged commonality with a nuclear carrier as a justication for use of steam propulsion in a conventional carrier is IMHO nonsense.
1. most of the logistic and personnel skillset burden of marine steam turbine propulsion is in boiler furnace operation and maintenance, not the turbine itself. Fossil fuel boilers and nuclear heat exchangers do not share leveragable commonality.
2. Safety and loop isolation in nuclear propulsion means the steam turbine in a nuclear ship would operate at much lower temperature and pressures than modern fossil fuel HTHP marine steam turbines. So the steam turbines themselves would be different. So logistic synergy would be limited.
The main reason why the chinese decided to use steam turbine in 003 are, IMHO, likely to be the following:
1. When 003 was designed, it has not yet been settled whether the ship would use EMAL or steam catapults, Steam turbine propulsion would naturally facilitate steam catapults, thus keeping the options open to decide on the catapult well after power plants abd hull construction had begun.
2. There was likely desire to reduce risk by maintaining as much of the proven design and components from 001 and 002 as possible. It may well have been judged not worth the risk and effort to design a new GT based propulsion arrangement, and a new interior layout to take advantage of GT driven IEP, for just 1-2 ships before the design would be thrown out when the next ship goes nuclear. So backwards compatibility rather than forward compatibility id more likely the driver.
These are both very legitimate concerns, and in the overall scheme of development of the chinese navy, allowing these two concerns to drive the power plant selection was very likely the correct decision.
But if the final configuration of the 003 class ships are examined in isolation, and not in the context of the PLAN naval design history, then a case can certainly be made that they would have been better ships if they had taken full advantage of GT as prime movers for their integrated electric propulsion.
BTW, the fact the GTs used in existing chinese surface ships are smaller than those in the QE class does not preclude their use in a carrier. the big benefit of integrated electric propulsion, compared to traditional direct mechanical drive propulsion, is your can much more easily gang up larger number of prime movers, in this case GTs, to achieve any desired level of total output.
