Qualification of a steady-state reactor physics methodology for boiling water reactor core design and analysis

This thesis presents a reactor core model developed to simulate the Quad Cities-1 reactor core from initial critical through cycle 2 using newly developed reactor core physics methodologies. The reactor core is modeled using a nodal core simulator which includes a coupled neutronic/thermal-hydraulic, three-dimensional representation. Few group cross-sections for use in the core simulator are generated with a two-dimensional, fine mesh lattice physics code. Calculated results are compared with measured data from monthly in-core detector measurements through cycle 2, end-of-cycles 1 and 2 gamma scan measurements, distributed rod pattern startup reactivity, cold condition local criticality experiments, and high power steady-state reactivity. These calculations will be used, in conjunction with other benchmark calculations, to qualify the new reactor physics methodologies for steady-state Boiling Water Reactor design analyses for the Browns Ferry Nuclear Plant.

The results presented in this thesis identify areas in the methodology which are improved and other areas which require further refinements. The new core physics methodologies provide improved predictions of hot operating reactivity and power distributions. However, cold reactivity calculations and simulated traversing in-core probe readings are shown to be less consistent and possible causes are presented.