The advantage is 24Na's short (14.9 hour) half-life, not the lack of solubility in water. Half of the original radiation will be gone in 15 hours, and close to 90% in two days.
I understand half life. My point moisture currents can spread water soluble things very far very quickly.
Think of it this way, what happens if there's a catastrophic sodium leak? The winds carry it far and the Na gets into everything because it will be diluted into the wind's moisture. Won't you breath the radioactive Na from the air's moisture?
Think of it this way, what happens if there's a catastrophic sodium leak? The winds carry it far and the Na gets into everything because it will be diluted into the wind's moisture. Won't you breath the radioactive Na from the air's moisture?