It’s a theoretical design and it isn’t just salt water but using plutonium it uranium salts:
The nuclear salt-water rocket (NSWR) is a theoretical type of nuclear thermal rocket designed by Robert Zubrin.[1] In place of traditional chemical propellant, such as that in a chemical rocket, the rocket would be fueled by salts of plutonium or 20-percent-enriched uranium.
It’s a theoretical design and it isn’t just salt water but using plutonium it uranium salts:
Seems safer than Project Pluto, but I can’t think of anything less safe than Project Pluto.
Project Orion.
Nah getting pushed along by literal nuclear bombs seems super safe.