Design and experimental assessment of thermal stratification effects on operational loading of surge line of Unit 5, Novovoronezh NPP

Calculation and experimental assessment of effects of thermal loading factors on the stress-deformed state of SL demonstrated that effects of thermal stratification and thermal fatigue significantly affect the operational loading of the pipeline. It is noted that zones with maximum accumulated damage determined according to the results of calculations coincide with places where factual operational defects were detected. Procedure involving treatment of SL welded joints by the method of surface plastic deformation is suggested as the compensatory measure aimed at extending the SL residual lifespan.