Inherent Safety in the Design of Future Nuclear Plants

By making public health and safety a primary criterion in the initial conceptual design, future nuclear power plants could be made inherently safe to the point where they could be legitimately sited nearly anywhere instead of only in the most remote locations. It is found that an unpressurized, “pool-type,” sodium-cooled reactor, which would be controlled by the movement of bottom entry fuel assemblies, would allow a heavy shielding dome to be permanently installed directly over the reactor. This would allow on-line refueling and the continuous removal of the free gaseous fission products from the reactor to a naturally cooled, well-protected site. It would also allow high-temperature decay heat to be transported directly to the ever present atmosphere by a system that is simple enough to preclude fuel melting in a shutdown reactor.