At present, there is a disparity between the characteristics measured on nuclear reactor components and test specimens. In particular, in the pattern of crack-tip stresses and strains causing plastic flow and fracture (the so-called constraint effect). Crack-tip constraint in components is generally lower than in test specimens and effective toughness is correspondingly higher. The toughness measured on standard test specimens is therefore likely to underestimate that exhibited by cracks in components. The purpose of this project is to develop and validate, by an iterative process of experiment and analysis, innovative procedures for assessing possible states of crack-tip constraint in ageing nuclear pressure boundary components.
This will provide nuclear plant operators and regulators with:
(i) improved predictions of safety margins under normal and abnormal conditions, using a validated defect assessment methodology;
(ii) improved lifetime extension arguments.
Funding SchemeCSC - Cost-sharing contracts
OX11 0QJ Didcot,harwell,chilton
WA3 6AS Warrington
91191 Gif Sur Yvette
1755 ZG Petten
250 68 Rez - Praha
37831-8063 Oak Ridge
92084 Paris La Defense