Implementation of on-line fatigue monitoring methodology in Heavy Water Plant, Kota for remnant life assessment programme

Fatigue, creep and creep-fatigue interaction phenomena are important in the design and operation of components used in nuclear industry, thermal power plant and chemical process plant. Extension of life of the existing plants is a major concern to plant management. Recently, a methodology has been developed to predict the aging degradation of various components subjected to severe fluctuating loading conditions. This methodology converts the plant transients to responses on the structure using Green's function technique. The stresses on the structure due to combined thermal and mechanical loading is transformed into stress frequency spectrum using Rainflow cycle counting algorithm. Using material fatigue data, fatigue usage factor is computed. There is a proposal to implement this on-line fatigue life monitoring system to estimate the fatigue degradation of components at Heavy Water Plant, Kota. This present paper describes the implementation of this methodology for remnant life assessment of components. (author). 3 refs., 3 figs