These salts are all higher melting, less compatible with steam and generally more corrosive than NaNO3-KNO3 eutectic.jagdish wrote:http://nuclear.inl.gov/deliverables/doc ... l_salt.pdf
NaCl-MgCl2, KCl-MgCl2, KF-ZrF4,and NaF-NaBF4 could be the cost effective salts for heat storage. They could be in a storage outside the core as partly melted salts for phase change energy to add to heat storage.
NaNO3-KNO3 eutectic is a very good allround heat storage medium, good with steam, easy on stainless steel, low melting, cheap, nontoxic, available in massive supply, etc. etc.
In a future higher temp storage system the chlorides look better on balance, but it remains to be seen that there are substantial advantages to going above 570C in the storage. Creep and corrosion become serious issues, you want a big tank but big tank in creep regime means massively thick walls, which is difficult to make and suffers thermal stress etc.
It doesn't look like we can improve much on $100/kWe for the tank and salt cost of the nitrate.