But if it presses against the rest of the universe then the faster it goes the less efficient it should become.
But everybody ignore the real reason this will never work , and that would be heat from the power plant.
You would have to radiate that heat out somewhere from the power plant and even with current tech that is no small feat.
For example Nuclear submarines get rid of heat by sucking in cold ocean water and spewing out hot heat sink water. This won't work in space, there isn't any ocean. To radiate this much heat into space the radiators would literally be square kilometers.
The EATCS is capable of rejecting up to 70 kW, that's what they use on the space station The PVR – the radiator Each flow path is independent and is connected to one of the two PFCSson the IEA. In total, the PVR can reject up to 14 kW of heat into deep space. The PVR weighs
1,633 pounds (740.7 kilograms) and when deployed measures 10.24 feet (3.12 meters) by 44.62
feet (13.6 meters). When the ISS assembly is complete, there will be a total of four PVRs or over100 square meters
Physics and law enforcement, ruining all my fun once again
I am not a nuclear physicist, but play one on the internet.