I personally favor the molten salt designs over liquid metals even though it may be more corrosive, sodium metal is also very corrosive and this has caused plumbing failures and subsequent fires in nearly every reactor that has incorporated it, where as the Oakridge molten salt reactor ran almost five years (from January 1965 to December 1969), 13,000 of those hours at full power, and they even did an experiment where they shut off cooling and pulled out the control rods, and all that happened was the salt expanded slowing the nuclear reaction and the reactor self-regulated, they let it do this for 24 hours. We really need to have absolutely safe reactors like this, not semi-safe reactors that occasionally catch fire and spread radioactivity into the environment.