A reactor design whose "inherently" safe process directly provides a "passive" safety component during a specific failure condition in "all" operational modes is typically described as relatively fail-safe to that failure condition. However most current water-cooled and -moderated reactors, when scrammed, can not remove residual production and decay heat without either process heat transfer or the active cooling system. In other words, whilst the inherently safe heat transfer process provides a passive safety component preventing excessive heat while the reactor is operating, the same inherently safe heat transfer process "does not" provide a passive safety component if the reactor is shut down (SCRAMed). The Three Mile Island accident exposed this design deficiency: the reactor and steam generator were shut down but with loss of coolant it still suffered a partial meltdown.