A comprehensive interactive computer program for strategic studies of the light water reactor (LWR) fuel cycle has been developed, incorporating simple models for estimating material flow, correlations for discharge fuel composition (as a function of core enrichment, burnup, fuel-to-moderator ratio, and number of batches), algorithms for nuclear fuel cycle economic computations, and an ore resource/cost relationship. These models have been linked together to yield fuel cycle cost equations, in terms of the unit cost of each process step, in a form suitable for estimation of breakeven costs and for sensitivity analyses. The program has been employed in a number of case studies to evaluate the impact of the introduction of the recycle mode, extended burnup, more batches in the core, low-enrichment-cost technologies, and a reduction in enrichment plant tails assay. It is concluded that LWRs in the United States will be operated in the once-through fueling mode for many decades into the future unless a radical technological breakthrough leading to a substantial reduction in reprocessing cost can be effected. The computer program developed in the present work can be used to evaluate this and other alternative scenarios, involving different cost projections of the user’s choosing.