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Effect of non‐uniform reactor cooling on fracture and constraint of a reactor pressure vessel
Author(s) -
Qian Guian,
Niffenegger Markus,
Sharabi Medhat,
Lafferty Nathan
Publication year - 2018
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/ffe.12796
Subject(s) - reactor pressure vessel , fracture mechanics , pressure vessel , materials science , fracture (geology) , nuclear reactor , fracture toughness , structural engineering , constraint (computer aided design) , stress (linguistics) , coolant , mechanics , brittleness , loss of coolant accident , nuclear engineering , engineering , mechanical engineering , physics , composite material , linguistics , philosophy
In the lifetime prediction and extension of a nuclear power plant, a reactor pressure vessel (RPV) has to demonstrate the exclusion of brittle fracture. This paper aims to apply fracture mechanics to analyse the non‐uniform cooling effect in case of a loss‐of‐coolant accident on the RPV integrity. A comprehensive framework coupling reactor system, fluid dynamics, fracture mechanics, and probabilistic analyses for the RPVs integrity analysis is proposed. The safety margin of the allowed RT NDT is increased by more than 16°C if a probabilistic method is applied. Considering the non‐uniform plume cooling effect increases K I more than 30%, increases the failure frequency by more than 1 order of magnitude, and increases the crack tip constraint due to the resulting higher stress. Thus, in order to be more realistic and not to be nonconservative, 3D computational fluid dynamics may be required to provide input for the fracture mechanics analysis of the RPV.