Fracture Mechanics and Strength of Materials

Assessment of Brittle Fracture Strength of Welded Control Rods in the WWER-1000 Nuclear Reactors

Oleksii Makhnenko, Oleksii Milenin

E.O. Paton Electric Welding Institute of NAS of Ukraine

https://doi.org/10.15407/msse2025.01.199

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Keywords

Control Rod system, WWER-1000, nuclear reactor, control rod, weld, 42KhNM, finite element modeling, brittle fracture, safety factor, postulated defect

Abstract

The strength of welded control rod joints in the WWER-1000 Control Rod System was assessed using finite element modeling and the postulated defect method. Residual and operational stresses, irradiation effects, and subsurface crack behavior were considered. Results show that even under conservative assumptions, the minimum safety factor exceeds 2.14, ensuring structural integrity over 10 years of extended service.

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