Regardless of beneficial associated with internal waste dump (IWD) method, practices of this method within boundaries of pit-slope have some serious problems on stability issues due to this area is zone of potential failure. This zone is known as dynamic reactive zone which is easy to deform by external force, and inherent dangers of failure posing a threat to slope. Therefore, it is paramount to study the induced shear stress behavior in this zone particularly when IWD method is adopted within this zone. In this paper, a numerical study for investigating IWD-induced shear stress behavior has been carried out using Finite Element Method (FEM) with Strength Reduction approach. Different scenarios as per pit-slope depths, IWD heights and buffer zone lengths have been accounted and simulated using PHASE 2 to understand changes in induced shear stress imposed on the pit-slope. It is found that shear stress imposed on pit slope seems change dramatically with increasing IWD height for case of buffer zone length is less than 100-m-long.