It Will Be Even Bigger Than The Sea Wolf Class
If the SSN(X) comes with the necessary weapons and features to outperform its competition, it needs a larger hull than the Seal Wolf and Virginia models. 9,100 tons can be carried by the former, whereas the latter has a capacity of 7,800 tons.
The Engine Might Rely On Two Types Of Fuel
A vessel that big will need a lot of power, as you can imagine. An engine that runs on both diesel-electric and nuclear power should come with a new design. There is still plenty of planning to be done, nevertheless.