The primary loop (that contains all the fuel salt and fission products) is inside a can so if we get a leak in the primary loop the salt will be contained inside the can. The can drains to the fuel dump tank (FDT). Both the can and FDT get passively cooled by the membrane and all entrance pipes come in from above so there is no weakness at the bottom.
These in turn are inside a silo, which is inside the silo hall. All total there are four barriers to break through before we get radioactive release.
Further, the fission products are combined with fluoride upon forming (when you fission UF4 the uranium is split into two fission products and the F4 is available for recombining with the fission products). Most of the fission products like to stay in the salt so even if the salt gets spilled the fission products won't wander farther than the salt spill.
It will be rather intensely radioactive. A person cannot approach it. A cleanup like this would have be done robotically. If the spill is contained in the can then the whole can is designed to be sealed and shipped back to the can recycling center where there are facilities for cleaning up the can. The main point though is that the spill is contained within the building and does not spread to the environment. A worst case accident becomes an economic loss of the reactor rather than a mass evacuation.
These in turn are inside a silo, which is inside the silo hall. All total there are four barriers to break through before we get radioactive release.
Further, the fission products are combined with fluoride upon forming (when you fission UF4 the uranium is split into two fission products and the F4 is available for recombining with the fission products). Most of the fission products like to stay in the salt so even if the salt gets spilled the fission products won't wander farther than the salt spill.