Optimization study of LEU fuelled homogeneous aqueous solution nuclear reactors for short lived isotopes production

Low enriched uranium (LEU) based solution reactors possess the potential to meet increasing demand of /sup 99/Mo and other short lived fission product radioisotopes being used in medical field. In the current study, optimization and neutronic design calculations were carried out for LEU homogenous aqueous solution reactor with uranyl nitrate as a solution fuel. Lattice calculations and core modeling were performed employing available standard nuclear reactor codes WIMSD and CITATION. Calculation procedure was verified using experimental published data and simulated criticality results were compared with the published data. After verification of the calculation methodology, optimization and design calculations were performed for four different uranium enrichments (5%, 10%, 15%, and 19.99%) of the uranyl nitrate solution. The restraints on peak power density of solution reactors, annular geometry is suited as compared to the cylindrical geometry. Among the four considered enrichments in the analysis, 19.99% enriched uranyl nitrate solution with annular geometry presents optimum design parameters for the homogeneous aqueous solution reactor. Critical fissile mass profile as a function of uranium concentration for annular geometry is shown. (orig./A.B.)