Analysis of Uranyl Nitrate Hexahydrate Composition for Optimum neutron Multiplication

Sbcritical Assemby for Molybdenum Production (SAMOP) is a concept of nuclear reactor where the neutron multiplication factor (keff) less than one (keff ~ 0.99). Therefore, SAMOP reactor need an external neutron source for its operation. Uranyl Nitrate Hexahydrate, UO2(No3) 6H2O or UNH is used asa fuel as well as terget material for 99Mo production. The 99Mo isotope is used to generate 99mTc which is the most widely used radioisotopes for diagnostic in nuclear medical field. The composition of Urannyl Nitrate Hexahydrate (UNH) should be analyzed by calculation methods to achieve the required subtrical level in the SAMPO core i.e. k-eff ~ 0,99. Methodology for this analysis is an elemental composition calculation of UNH, with enrichment of uranium of 19,75% and 2,81 gr/cm3 of density. The analysis resukt shows that the elemental composition of 235U, 238U, N, O and H are 4,8715%, 20,2009%, 5,3445%, 37,4138% and 32,069% respectively, and therefore, the composition of U and N-O-H are 25,1724% and 74,8276% respectively. The composition is then used as input for the neutronic analysis using the WIMS-D/4 computer code for keff calculation of SAMOP. The Result Shows that the optimum keff of 0.99 is acgieved with the above elemental composition.