Abundant and low cost material. Cleaning with chlorine produces non-toxic table salt. Compatible with other materials used in the core (does not react or dissolve stainless steel) so no special corrosion protection measures needed. Low pumping power (from light weight and low viscosity). Maintains an oxygen (and water) free environment by reacting with trace amounts to make sodium oxide or sodium hydroxide and hydrogen, thereby protecting other components from corrosion. Light weight (low density) improves resistance to seismic inertia events (earthquakes.)
