Assessment of the 2D/1D implementation in MPACT

The 2D/1D method is used in the MPACT code to obtain 3D solutions of the Boltzmann transport equation for practical reactor geometries. The OECD C5G7 transport benchmark problem is used first to assess the accuracy of the method with a fixed set of cross-sections. The VERA Core Physics Progression Problems are then used to compare the accuracy of the transport solver using a 56-group library based on ENDFB-VII.0. Single assembly PWR designs are simulated, and the eigenvalue and pin powers are compared to continuous-energy Monte Carlo results. A 3x3 assembly cluster with a control rod inserted into the center assembly is then compared to Monte Carlo to assess the ability of MPACT to predict a control rod worth curve. Finally, MPACT is used to simulate the initial critical states of a full 3D initial core of a PWR at zero power conditions. (author)