Re: Storing hydrogen is an absolute pain
Yes pumping radioactive salt around pipes is not a great idea, as they will always leak, and when they do you have an even more difficult cleanup problem than with a sodium cooled reactor.
However there are two proposed ways around this problem. Thorcon and Terrestrial Energy both propose to use a pool type reactor in a can that is replaced every seven years (this is possible with a molten salt cooled reactor vessel as they are unpressurized and are not housed in a steam explosion resistant steel and conrete containment dome.
Moltex Energy has possible an even simpler solution of putting the fuel salt (a Chloride salt) in vented steel pins*, controlling corrosion by having a lump of zirconium metal in the bottom (to make the salt strongly reducing), thenhaving these pins cooled by a flouride salt in a pool type reactor. This gets rid of the need for an online chemical processing plant as the fission products just remain in the fuel pins which are removed from the reactor every few years like standard uranium oxide ceramic fuel pins in today's pressurized water reactors.
*Today's standard uranium oxide fuel pins have to be removed somewhat prematurely due to the build up of Xenon gas (a fission product) in them that prevents the reactor from sustaining a chain reaction, another problem is that that gas in the tubes builds up to about 60 atmospheres (I think). The Dounreay fast sodium reactor experiment in Scotland tried to deal with these issues by having a uranium metal alloy sitting in vented fuel pins (the uranium sat in liquid sodium inside a steel fuel pin). You wouldn't want to try this in water cooled reactor as sodium and water react violently, but in a sodium cooled reactor it isn't a problem.However as radioactive fission products of Cesium, Iodine, and Strontium are produced, the metals (which are gases at reactor temperatures) vented out into the sodium coolant outside, making it highly radioactive. In Moltex's design the Iodine is still reduced to a non volatile Sodium Iodide salt that stays in the fuel pin, but the Cesium and Strontium are converted into Cesium Chloride and Strontium Chloride non volatile salts that also remain in the fuel pins (precipitating Zirconium metal ZrCl + Cs > CsCl + Zr).
https://www.youtube.com/watch?v=7qJpVClxzVM&t=1164s