Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) Version 8: Technical Reference (NUREG/CR-7039, Volume 2)

On this page:

Download complete document

Publication Information

Manuscript Completed: March 2011
Date Published: June 2011

Prepared by:
C.L. Smith, S.T. Wood

Idaho National Laboratory
Battelle Energy Alliance
Idaho Falls, ID 83415

D. O'Neal, NRC Project Manager

NRC Job Code N6423

Office of Nuclear Regulatory Research

Availability Notice


The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of computer programs that were developed to create and analyze probabilistic risk assessment (PRAs). Herein information is provided on the principles used in the construction and operation of Version 8.0 of the SAPHIRE system. This report summarizes the fundamental mathematical concepts of sets and logic, fault trees, and probability. This volume then describes the algorithms used to construct a fault tree and to obtain the minimal cut sets. It gives the formulas used to obtain the probability of the top event from the minimal cut sets, and the formulas for probabilities that apply for various assumptions concerning reparability and mission time. It defines the measures of basic event importance that SAPHIRE can calculate. This volume gives an overview of uncertainty analysis using simple Monte Carlo sampling or Latin Hypercube sampling, and states the algorithms used by this program to generate random basic event probabilities from various distributions. Also covered are enhance capabilities such as seismic analysis, Workspace algorithms, cut set "recovery," end state manipulation, and use of "compound events."

Page Last Reviewed/Updated Thursday, March 25, 2021