Comparison of Bare-Lattice Calculations Using MCNP Against Measurements With CANFLEX®-LEU in ZED-2

Abstract

This paper summarizes bare-lattice calculations performed using MCNP5 and compared against full-core measurements performed in the ZED-2 Critical Facility at Atomic Energy of Canada Limited’s Chalk River Laboratories. The results demonstrate that the total buckling calculated from a bare-lattice model in MCNP5 with the axial and radial dimensions adjusted to match the k-effective offset of a full-core post-test simulation matches the total buckling value measured in ZED-2 within the uncertainties of the calculation and measurement. The study shows that the calculated k-effective offset of a post-test simulation of a ZED-2 lattice modeled using MCNP5 is solely a property of the lattice and is not related to the large radial and axial leakage in ZED-2 and the surrounding D2O and graphite reflector.