Ultra high flux reactor design: probing the limits of plate fuel technology

This paper examined the capabilities and limitations of the plate fuel technology for producing unprecedented thermal neutron flux levels exceeding 1016 n/cm2.s. The requirements for a flux configured over a large volume, and accessible to experimental instruments, as well as isotope production and materials irradiation access, dictates that the flux peak be generated external to the core and, most efficiently, in a large D2O pool. A conventional thin cylindrical shell design appears to be limited to flux levels somewhat below goal values by plate temperatures and hydraulic conditions in the long, thin coolant channels, and to be life limited by cladding oxidation. A split or ''double donut'' core configuration with much shorter heated flow paths and a coolant mixing plenum between the upper and lower core sections, appears to be capable of enhanced thermal hydraulic performance, as well as improved neutronic access. It appears that evolutionary, rather than revolutionary, advances in plate-fuel technologies will indeed be capable of producing 1016 n/cm2.s goal flux levels in a user friendly environment