Biodosimetry relies on calibration curves to convert biological damage induced by ionizing radiation to an absorbed dose. Health Canada generates these curves by irradiating biological samples with X-rays, though exposures scenarios could consist of other types of radiation which are challenging to replicate in the laboratory. The ultimate goal of this work is to model the X-ray setup using Monte Carlo methods and to validate the model using in-laboratory measurements. The model was iterated through preliminary and final testing phases in different EGSnrc applications (egs++, SpekPy and BEAMnrc) and optimized using variance reduction techniques, resulting in multiple models. The X-ray spectra produced from each model were compared and found to be equivalent. Model outputs were also compared against laboratory measurements to identify the most accurate model. The final model output will be used in the next phase of the project to model radiobiological damage.