In this study, the authors have studied about cost estimation of nuclear power generation plant. Supplementary variables have been used for mathematical form ulation of the model. Laplace transforms is being utilize to solve the mathematical equations. Some particular cases and asymptotic behaviour of the system have also been derived to improve practical importance of the model. Expressions for availability and cost function have been computed. A numerical example together with its graphical illustration has been appended at the end to highlight important results.