Application of Graded Approaches for Safety Analysis at Point Lepreau Nuclear Generating Station

Abstract

The application of graded approaches in scoping and selecting safety analysis to be performed is an integral aspect of the Canadian regulatory approach that draws upon the international atomic energy agency (IAEA) general safety requirement (GSR) Part 4. Graded approaches, in general, can be risk- informed or not and are subject to regulatory acceptance prior to application. At Point Lepreau Nuclear Generating Station, graded approaches have been applied for: (a) the selection of which analyses to update based on an event-specific gap assessment where various attributes were scored and ranked against regulatory document REGDOC-2.4.1 requirements; and, (b) to determine if further analysis for anticipated operational occurrences (i.e. evaluation of fuel and pressure tube fitness for service) to demonstrate Level 2 defense is warranted. This paper will provide additional details of the graded approaches that have been applied to constrain scope of the safety analysis program at Point Lepreau and, to ensure that finite resources are directed to where they are most needed in support of the overall safety case and meeting regulatory requirements.