EPRI CORETRAN-01 benchmark results - 081

EPRI CORETRAN-01, a three-dimensional neutronic and thermal-hydraulic simulation code for use in reactor analysis, has been benchmarked against Northern States Power's Prairie Island and Monticello reactors through twelve cycles of operation. The two Prairie Island reactors are Westinghouse two loop units with an asymmetric 14x14 lattice design utilizing up to 8 w/o Gadolinium while Monticello is a General Electric 484 bundle BWR. All reactor cases were executed in full core utilizing 24 axial nodes per assembly in the fuel with one additional reflector node above, below and around the perimeter of the core. Cross section sets used in this benchmark effort were generated by EPRI CPM-3, Studsvik CASMO-3 and Studsvik CASMO-4 to allow for separation of the lattice calculation effect from the nodal simulation method. Cases exercised the depletion - shuffle - depletion sequence through four cycles for each unit using plant data to follow actual operations. Flux map calculations were performed for comparison to corresponding measurement state points. Additionally, startup physics testing cases were used to predict cycle physics parameters for comparison to existing plant methods and measurements. These benchmark results agreed well with both current analysis methods and plant measurements indicating that CORETRAN-01 may be appropriate for steady-state physics calculations of both the Prairie Island and Monticello reactors. Additional plant specific validation work will need to be conducted in order to fully assess the adequacy of CORETRAN-01 for use in a full production environment. No attempt was made to apply CORETRAN-01's kinetics capability to analyzing transients for these plants, but the steady state results encourage further investigation. (author)