POSTED 18.10.21

EASL - Supporting Evidence for Moderate Energy Lines 2A Guillotine Break Claim

During the generic design assessment (GDA) process for the UK EPR the Office for Nuclear Regulation (ONR) stipulated that the failure mechanism of double ended (2A) guillotine break must be adopted for all internal flooding assessments pertaining to loss of divisional segregation. Previously a leak rate associated with a breach size of DT/4 had been assumed for moderate energy pipework, as per common practices within the international nuclear industry.