Don’t confuse the heating with the actual propulsive source.
Nuclear is for heating. The steam is created and drives the engine. As with other heat sources such as oil. But the water is the driver.
I don’t know why you’re writing this to me as if it weren’t in line with what I wrote, namely that technically nuclear is a form of steam propulsion. I was just chuckling at the way AnalogReigns could be read as proposing nuclear reactors in cars.
Nukes can produce quite a lot of force. Once.