This article deals with use of Probabilistic Safety Assessment (PSA) model for infrastructure risk assessment. The first part of the paper provides background information leading to the selection of PSA as the preferred method for risk assessment. The article also discusses the initiating events, consequential events, and the consequences, dealing with scenarios and detailed list of various failure events, the associated failure modes and their cause/effect which could deal with various infrastructure interdependency risk. Example of event tree and fault-tree for selected infrastructure are discussed and presented. Emphases are given on the advantages and disadvantages of using PSA for infrastructure risk assessment. Main advantages are in the capability of PSA to deal with numerous scenarios to provide comparative risk assessment for various infrastructure types and some interdependencies. PSA is proven methodology for combining available data with expert opinion to model complex systems risk accounting for numerous number of initiating events, systems reliability, human responses and common causes. Final results are both important for qualitative and quantitative usage in infrastructure safety optimization. This is valuable inside particular infrastructure type or between infrastructures for specific region or country. Example of nuclear power plant PSA model and interdependency on power infrastructure is presented.