INTEGRATED EXAMINATION OF TECHNICAL CONDITION OF MOLYBDENUM BOATS

摘要

Pelletized fuel is used in nuclear power engineering. After press-powder being prepared and pressed the obtained green pellets are converted to high-strength ceramic fuel by sintering in the reducing medium. Sintering is performed continuously in tunnel-type furnaces at 1750°C. Before being sintered green pellets are subjected to slow heating up to 600-800°C, and after being sintered - to slow cooling. Total process duration for ceramic pelletized fuel production makes 30-40 hours. During all this period pellets are located in a special container i.e. molybdenum boats. The important parameter of molybdenum boats is their working capacity that shall comprise 250-300 working cycles taking into account the reconditioning. In practice boats withstand considerably less working cycles. It is explained by the fact that their working capacity is influenced by the chemical composition of structure, construction and characteristics of production practice.