The relevance of the research is caused by the requirement for uniform filling of transport casks with uranium hexafluoride and for solution to stop filling it according to the degree of its fill up. This requirement can be achieved by the commissioning of an automated control system for deposition apparatus. The main aim of the research is to develop the algorithm for calculating the cooling interval of the deposition apparatus tube bundle, which ensures the accumulation of the given deposit layer thickness in an automated mode. Object of the research is uranium hexafluoride deposition apparatus. Methods: mathematical modeling of technological processes; full-factor experiments on the mathematical model; regression analysis; statistical analysis; field experiments on the deposition apparatus for uranium hexafluoride production. Results. Duration of cooling interval is used as a control action for implementation of stabilization system for a given deposit layer thickness on the cooled element (tube bundle). The mathematical model of the deposition apparatus is used to conduct numerical experiments and to find an analytical dependence for calculating the duration of the cooling interval. The mathematical model describes the heat exchange and mass transfer occurring in the apparatus. The adequacy of the model is confirmed by comparing the results of mathematical modeling and production data. The conclusion about the adequacy of the model is made by the magnitude of the reduced standard error of prediction by the model of production data. The equation for calculating the cooling interval was obtained using the developed mathematical model as a result of a full factorial experiment. The equation allows calculating the required duration of the cooling interval for the tube bundle, during which the operator-specified deposit layer will be accumulated.