Most studies clearly presented a markedly higher cost for the closed fuel cycle (but consistent with EPRI). Fuel cycle costs are a small fraction of the total LCOE. Therefore the difference in total LCOE is not so large.
Closing the fuel cycle may make sense for non-economic reasons. The higher LCOE purchases the non-economic benefits. Uncertainties in cost elements are large.
Fast reactor costs. Disposal costs, whether for the once-through cycle or for the closed cycle.