CANDU are fine reactors, but the US uses pressurized water reactors (64) and boiling water reactors (31), which are better. Why? Reactors have various feedback

CANDU are fine reactors, but the US uses pressurized water reactors (64) and boiling water reactors (31), which are better. Why? Reactors have various feedback loops, some positive, some negative. You want negative feedback loops rather than positive ones. One of the main feedback loops in water cooled reactors is negative in PWRs and BWRs and positive in CANDU reactors. That doesn't mean CANDU reactors are not usable, but PWRs and BWRs are inherently safer.