It depends how they are designed. Same as regular uranium reactors. Thorium isn't a reactor fuel after all, it's what you use to breed more fuel. The actual fuel is still uranium. Thorium turns into uranium-233 then that is the fuel. Normal reactors use uranium-235. Both isotopes can be made to be passively safe.
It depends how they are designed. Same as regular uranium reactors. Thorium isn't a reactor fuel after all, it's what you use to breed more fuel. The actual fuel is still uranium. Thorium turns into uranium-233 then that is the fuel. Normal reactors use uranium-235. Both isotopes can be made to be passively safe.