Kinetics equations using two assumptions describe an ideal cascade with accuracy. Using the kinetics equations, it is found that if the decrease of the separation factor in a selected stage is small, the product can be withdrawn at the product assay allowed for shipment without stopping the operation of the ideal cascade composed of the model centrifuges (∼4 kg SWU/yr, α = 1.135). Moreover, the fraction of centrifuges permissible to stop in case of an accident is found to be 4 to 5% of the model centrifuges in each stage in the enriching section of the ideal cascade.