You would not need the huge cooling towers and such obviously. And you would not need to collocate with a body of water.
The Brayton Cycle simply means that the power plant will use a gas turbine rather than a steam turbine. Other than that it will not really effect system efficiency much.
The laws of physics require a heat sink to absorb waste heat from any heat engine.
Thermodynamic efficiency of any system is limited to about 40%. Because your salt cooled reactor adds a second heat exchanger between the turbine and the heat sink it will be limited to about 30 percent. The other 70% of the heat generated in the reactor has to go somewhere, thus the large body of water.
I work in a 1300 megawatt nuclear plant. That plant generates 3500 megawatts of thermal energy. That leaves 2200 megawatts of waste heat that has to be rejected to some place. We use a rather large cooling tower that has 540,000 gallons per minute flowing through it to cool the turbine’s condenser.
A similar sized salt cooled thorium reactor would need a similar heat sink with a similar water source. There are no exceptions.
This is something which will have to be addressed on exact water specifics. If you want specifics, I can recommend John Kutsch of the TEA.
thoriumenergyalliance@gmail.com