Potential application of FORM and SORM for PRA

The focus of this paper is two-fold: 1) a discussion of a process by which a probabilistic risk assessments (PRA) system model is used to direct a multi-disciplinary development project. 2) Under this framework, a potential technique for the application of the First-Order Reliability Method (FORM) and Second-Order Reliability Method (SORM) to provide probabilistic failure data for PRA of structural systems. Technique 2) is an elaboration of the analysis techniques described in chapter 14. Specifically, the technique relies on the concept of the limit state function in conjunction with varying levels of model fidelity, sound engineering judgment, and expert opinion. This methodology is complementary to the Response Surface Method presented and is best utilized during the conceptual or preliminary stages of a design project. This technique is beneficial when reliability data is not readily available and/or one is constrained by aggressive development schedules. As the design matures, the events in the system event tree can be systematically re-defined by a process that uses the results of refined physics-based models.