A linear time-dependent flux approximation for nuclide depletion based on a perturbation method

A method was developed for solving the coupled neutron/nuclide field equations using a linear time-dependent flux approximation that does not require an iterative solution. A perturbation method is used to form the first-order expansion of the time-dependent flux. Solutions of the resulting burnup equations are found to be computationally more efficient than current constant flux or linear flux approximation methods based on an iterative solution. The methods proposed here were validated using a multigroup, zero-dimensional calculation for a fast reactor core model. (author)