The power numbers are a bit confusing. It is stated that the sub is powered by two 380MW nuclear reactors. It almost doesn't make sense that a submarine can output as much power as a large power station. Though, the reactors power appears to be thermal and not electrical.

At 746 watts to a horsepower 760MW is pretty much 1,000,000 horsepower. But the stated shaft horsepower (shp) driving the props is given at 80,000 shp which is a 1/10th the output of each reactor. Granted there are losses and the rest of the ship needs power but not 90%.