2-D pressurized water reactor whole core benchmark problem development and mocum program verification

The need to solve larger-scale and highly heterogeneous reactor problems is urgent nowadays; different computational codes are being developed to meet this demand. Method of characteristics unstructured meshing (MOCUM) is a transport theory code based on the method of characteristic as the flux solver with an advanced general geometry processor. The objective of this research was to use the MOCUM program to solve the whole core, highly heterogeneous pressurized water reactor (PWR) benchmark problem, to determine its efficiency in solving complicated benchmarks, the large scale full-core PWR benchmark problem presented in this work was modeled for high heterogeneity at the core and assembly level, and depicts a realistic reactor design. The design of the core is a 15×15 assembly arrangement and each assembly is based on the C5G7 assembly design, i.e, 17×17 fuel pins. The problem was simplified for faster computation time by using the 1/4 symmetry of the core. MATLAB is used for the visualization of the neutron flux for each group, and the fission rate. MOCUM result shows good agreement with monte carlo N-particles (MCNP6) solution with a -0.025% difference in eigenvalue (keff). The pin and assembly power calculated with MOCUM, shows good agreement with that of MCNP6; the maximum relative difference for pin and assembly power was -2.53% and -1.79% respectively. The power profiles from these two computational codes were compared and used to validate the MOCUM solutions