Reactivity Effect of Cross-Section Processing for Moist Bulk-Oxide Criticals

摘要

Good multigroup cross-section data is necessary if accurate analyses of critical or slightly sub-critical systems are performed. How the flux spectrum as calculated by the Nordheim method and by a more exact method can ultimately affect the calculated multiplication and/or critical mass of slightly moderated bulk-oxide systems is shown. Self-shielded multigroup cross sections were generated using the Nordheim method as implemented in the NITAWL code and by a more exact method as implemented in the ROLAIDS code. To eliminate geometric effects, both codes were used to generate cross sections for an infinite homogeneous media of U sub 3 O sub 8 and water (U = 4.65% Uranium 235). (ERA citation 05:021015)