Challenges in using a probabilistic safety assessment in a risk informed process (illustrated using risk informed inservice inspection)

Many of the ongoing and expected uses of Probabilistic Safety Assessment (PSA)1A Probabilistic Safety Assessment (PSA) generally refers to an assessment of the accident frequency, e.g. the core damage frequency (CDF), while a Probabilistic Risk Assessment (PRA) also evaluates the health consequences, e.g. exposures. te new challenges to ensuring that the resulting conclusions are valid. This paper provides a summary of some of these challenges. Work conducted by the authors on Risk-Informed Inservice Inspection (RI-ISI) is used to illustrate these challenges. Means to address all of the challenges are not provided in detail in this paper. Several earlier papers discuss how these challenges can be addressed. References are provided for the interested reader (Chapman JR et al. In: PSA ʹ95, vol. 1, Seoul, 1995: 177–80; Chapman JR et al. In: ICONE-IV, New Orleans, 1996; Dimitrijevic VB et al. In: Croatian Nuclear Society International Conference, Opatija, 1996: 245–54; Dimitrijevic VB et al. In: Croatian Nuclear Society International Conference, Opatija, 1996: 255–62; Dimitrijevic VB. In: Yugoslav Nuclear Society Conference, Belgrade, 1996: 53–61; OʹRegan PJ et al. In: PSA ʹ95, Seoul, vol. 1, 1995: 403–5; OʹRegan PJ. In: ICONE-IV, vol. 5, New Orleans, 1996: 277–80).