> Water is by far safer in comparison to stuff that corrodes, and eventually eats through pretty much anything.
Problem with water is that for temperatures sufficient to run turbines at any decent efficiency, you need very high pressure, meaning expensive and bulky equipment. Hence it's not really usable as a heat storage medium.
Hot water or steam is actually surprisingly corrosive, though we have a lot of experience how to handle it properly.
> for sodium, you have no other option than putting in sacrificial material even if you use toughest nickel alloys, and there only is so much of it you can use.
Sodium is actually very compatible with normal structural stainless steels. E.g. when the steam generators for EBR2 were dismantled after 30 years of operation the sodium side were as if brand new.
Problem with water is that for temperatures sufficient to run turbines at any decent efficiency, you need very high pressure, meaning expensive and bulky equipment. Hence it's not really usable as a heat storage medium.
Hot water or steam is actually surprisingly corrosive, though we have a lot of experience how to handle it properly.
> for sodium, you have no other option than putting in sacrificial material even if you use toughest nickel alloys, and there only is so much of it you can use.
Sodium is actually very compatible with normal structural stainless steels. E.g. when the steam generators for EBR2 were dismantled after 30 years of operation the sodium side were as if brand new.