Application of leak-before-break concept for provision of the safety of pipings of WWER-1000 type reactors

摘要

A program of R&D on substantiation of applicability of leak-before-break concept to nuclear reactor piping has been outlined and fulfilled. J-R curves measured on full-scale samples cut out of a welded pipe with the working cross-section of 70×250 mm with through-thickness and semi-elliptical cracks in the circumferential weld metal were compared with similar curves derived on compact samples of ST-1T. It is found that the parameters of plastic fracture toughness measured on ST-1T samples are characterised by a higher level of reliability compared to those of full-scale samples.