The present project proposes instead a solution that consists in a cascade of three columns of medium height, similar to the one already constructed at NIRDIMT. The cascade proposed will have reduced maintenance costs, which will trigger the price reduction of the final product obtained, the enriched 13C, which is the most important result expected from the project. Available information regarding carbon isotope separation methods, shows that the proposed solution is new, at least in Europe, even for any other isotope types. A viable solution for modern isotope separation equipment is required also in different research centres in Romania. Due to the complexity of the actual project, the authors aim to conceive and to build a separation cascade at an experimental pilot stage. Based on these experimental data, the authors will develop a systematic design procedure for industrial scale equipment or for technological transfer to other plants. Another important objective however would reside in the complete automatic monitoring and control of the cascade. The proposed cascade consists of three single-column plants, thus the control problems mentioned previously for the single-column unit characterise also the cascade. Further problems arise also from the cascade connection of the columns, the conditions that have to be maintained for a proper operation of the entire cascade. From this point of view, the cascade control problem is a complex one, especially when the operation is extended to the industrial scale where the performance specification have a contradictory character: higher column load is necessary for grater productivity which leads to the operation close to the limit of stability.