It really depends. Osmosis is a chemical process, so if the source of the radiation would be filtered, then it would remove the radioactive component. If the water is made with radioactive isotopes of hydrogen and oxygen, it would just flow through.
But the desalination process is powered by the energy manufacturing, the water is not shared between them. I was more thinking about the safety and capability of the energy manufacturing, as fallout makes other systems much more difficult.
It really depends. Osmosis is a chemical process, so if the source of the radiation would be filtered, then it would remove the radioactive component. If the water is made with radioactive isotopes of hydrogen and oxygen, it would just flow through.
But the desalination process is powered by the energy manufacturing, the water is not shared between them. I was more thinking about the safety and capability of the energy manufacturing, as fallout makes other systems much more difficult.