We have recently developed and tested a new computational method for experiment prototyping at the Advanced Test Reactor (ATR). The method significantly reduces neutronic computation time while maintaining computational accuracy. In this thesis, we present the method and describe the techniques that we used to implement it. We then qualitatively and quantitatively analyze its performance for absorptive and multiplicative experiment perturbations over a single region and across multiple regions of the ATR. We conclude with a discussion of future research that might be conducted on the method. / text