2022 №04 (01) DOI of Article
2022 №04 (03)

Technical Diagnostics and Non-Destructive Testing 2022 #04
Technical Diagnostics and Non-Destructive Testing #4, 2022, pp. 12-16

Influence of residual process stresses on brittle fracture resistance of WWER-1000 reactor baffle in case of an emergency

O.V. Makhnenko, S.M. Kandala

E.O. Paton Electric Welding Institute of NASU. 11 Kazymyr Malevych str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua

At present, the majority of WWER-1000 reactors in Ukrainian NPPs are going through the procedure of extension of their service life. Reactor internals (RI) are one of the key elements of the structure, which limit the NPP beyond design life. Physical control of RI condition is rather difficult, and even impossible for some areas, so that mathematical modeling is the main method of prediction and analysis of the technical condition. Note that most of the studies in this area are limited to modeling the normal operation mode, but the project also envisages emergency situations (ES), characterized by a rather abrupt change of boundary conditions and loads that promotes formation of quite high stresses. The work analyzes how the residual process stresses generated during RI baffle manufacture, can affect the values of stress intensity factor on the contour of postulated cracks during ES. A significant influence of RPS on the baffle brittle fracture resistance during ES was revealed that should be taken into account at calculation-based substantiation of extension of service life of WWER-1000 type power units. 8 Ref., 2 Tabl., 7 Fig.
Keywords: WWER-1000, reactor internals, baffle, residual process stresses, emergency situation, crack-like defect, stress intensity factor

Received: 09.09.2022


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