Identification of regulatory requirements that have marginal importance to risk

The US Nuclear Regulatory Commission (NRC) has initiated a program to review the effectiveness of light water reactor (LWR) regulatory requirements in limiting risk. More specifically, the objective is to identify regulatory requirements which, if deleted or appropriately modified, would improve the effectiveness of NRC's regulatory program without adversely affecting safety. The initial scope of the program covers the LWR regulatory requirements and guidance associated with 10CFR50. The Pacific Northwest Laboratory (PNL), under contract to the NRC, is assisting in this program. This paper presents preliminary findings based on one element of the program, namely, a systematic effort to gather the views of various interested parties concerning selected aspects of current LWR regulatory requirements.