An evaluation of internal event level 1 PRA methods used in NUREG-1150

As part of the effort to support NUREG-1150, Sandia National Laboratories and its subcontractors have developed innovative techniques for efficiently performing internal event Level I probabilistic risk assessments. This methodology is one of the alternatives for industry to use in performing individual plant evaluations in the future. While this new methodology was very successful, there are some areas where improvements can be made. This paper evaluates the strengths and weaknesses of the methodology and makes some important recommendations for modifications in order to provide insights to future users. 10 refs.