POSTED 18.10.21

38. Investigation of the 20bar Threshold between high and moderate energy lines

EDF NNB currently uses a 20 bar threshold to delineate high energy lines (HEL) and moderate energy lines (MEL). The threshold is used as a process for establishing additional analysis to be performed as part of HEL break analysis. The Office of Nuclear Regulation (ONR) has challenged EDF NNB to provide substantiation that the 20 bar threshold used for the differentiation of HEL and MEL is an appropriate value.