MSRs have negative temperature reactivity coefficient and outlet temps around 700C at atm pressure. PWR is at measly 300C and 150 Bar.
If all control is lost, the salt expands as it heats up pushing the expanded volume out from the reactor core. The fission stops once the fuel is leaves the core region where the moderator is. Reverse is also true: you pull heat off from the loop, so the fuel-salt becomes denser, increasing reactivity. MSRs can naturally “follow” the load, if done right.
I recently deleted my +10y (cant remember anymore how old it was) old account. I had not logged in with it since the first exodus.
In my time, I started from the old reddit, saw the changes to more modern UI twice. I “collaborated” with the pixel art canvas event. (twice?) (last was fullout among us dithering) And finally saw the full revolt against spez that ended my journey there. (plus the complete enshittification of the reddit app)