While energetic material reactive burn processes such as the buildup to detonation are well understood for energetic materials like PBX 9501 that contain small amounts of porosity, the same is not true for highly cracked energetic materials. This work addresses this shortcoming by performing theoretical reactive burn calculations where thin submillimeter thick cracks permeating a PBX 9501 system are explicitly modeled. We use the Scaled Uniform Reactive Flow (SURF) model for the reactive burn calculations. Before considering highly cracked structures, we first show that SURF closely reproduces reactive burn experiments done on pristine and single air gap PBX 9501. For all cases of this investigation, a high-pressure shock is introduced by way of a high velocity impact to initiate a detonation in our cracked PBX 9501 structures. Using fully three-dimensional simulations and the physics code PAGOSA, we investigate the reactive burn process in cracked structures that have a propensity to have cracks either aligned with or orthogonal to the direction of wave propagation. While each crack structure has the same net crack porosity, we demonstrate that the reactive burn produced differs for the two cases. We also provide crack structure metrics, beyond porosity, that characterize the average crack orientation relative to the direction of wave propagation. Simulation results are provided for several variants of cracked structures. At the highest crack porosity studied here we observed the breakdown of stable detonation propagation. This high porosity case was achieved by doubling the average crack width, leaving all other features of the crack network unchanged. We conclude with a synthesis of our simulation observations to make general comments regarding how crack networks can affect points on the PBX 9501 detonation pop plot.