The AOA apparently looked at two options, using two of the s' 34 MW S6W reactors, and halving one of the two 550 thermal MW A4W reactors used in s. The first option would not even match "Zumwalt" for power, while the second option probably would not fit into the "Zumwalt" hull. On the other hand, it would give plenty of headroom for future weapon systems such as directed-energy weapons and railguns, hence the proposal for the ballistic missile defense ship of a larger hull with nuclear propulsion.