SAPHIRE is a fault tree and event tree analysis code the development of which, has been (and continues to be) sponsored by the U. S. Nuclear Regulatory Commission since the mid-1980's. The acronym SAPHIRE stands for “Systems Analysis Programs for Hands-on Integrated Reliability Evaluations,” and it was originally released as IRRAS (Integrated Reliability and Risk Analysis System) Version 1.0 in 1987. Since that time, the code has evolved significantly to the currently available SAPHIRE Version 7.26 (as of January 2006). The capabilities in SAPHIRE have been expanded to accommodate the advances in the state-of-the-art of probabilistic risk assessment (PRA), including...