United States Nuclear Regulatory Commission - Protecting People and the Environment

Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE): Summary Manual (NUREG/CR-6952, Volume 1)

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Publication Information

Manuscript Completed: October 2007
Date Published: September 2008

Prepared by:
S.T. Wood, C. L. Smith, K. J. Kvarfordt, S.T. Beck

Idaho National Laboratory
Battelle Energy Alliance
Idaho Falls, ID 83415

D. O'Neal, NRC Project Manager

Prepared for:
Office of Nuclear Regulatory Research
U. S. Nuclear Regulatory Commission
Washington, DC 20555-0001

NRC Job Code N6203

Availability Notice


The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) is a software application developed for performing a complete probabilistic risk assessment (PRA) using a personal computer (PC) running the Microsoft Windows operating system. SAPHIRE is primarily funded by the U.S. Nuclear Regulatory Commission (NRC) and developed by the Idaho National Laboratory (INL). INL's primary role in this project is that of software developer and tester. However, INL also plays an important role in technology transfer by interfacing and supporting SAPHIRE users, who constitute a wide range of PRA practitioners from the NRC, national laboratories, the private sector, and foreign countries.

SAPHIRE can be used to model a complex system's response to initiating events and quantify associated consequential outcome frequencies. Specifically, for nuclear power plant applications, SAPHIRE can identify important contributors to core damage (Level 1 PRA) and containment failure during a severe accident which lead to releases (Level 2 PRA). It can be used for a PRA where the reactor is at full power, low power, or at shutdown conditions. Furthermore, it can be used to analyze both internal and external initiating events and has special features for transforming an internal events model to a model for external events, such as flooding and fire analysis. It can also be used in a limited manner to quantify risk in terms of release consequences to the public and environment (Level 3 PRA).

SAPHIRE also includes a separate module called the Graphical Evaluation Module (GEM). GEM is a special user interface linked to SAPHIRE that automates the SAPHIRE process steps for evaluating operational events at commercial nuclear power plants. Using GEM, an analyst can estimate the risk associated with operational events (for example, to calculate a conditional core damage probability) very efficiently and expeditiously.

This report provides an overview of the functions available in SAPHIRE and presents general instructions for using the software. Section 1 presents SAPHIRE's historical evolution and summarizes its capabilities. Section 2 presents instructions for installing and using the code. Section 3 explains the database structure used in SAPHIRE and discusses database concepts. Section 4 explains how PRA data (event frequencies, human error probabilities, etc.) can be generated and manipulated using “change sets.” Section 5 deals with fault tree operations, including constructing, editing, solving, and displaying results. Section 6 presents operations associated with event trees, including rule application for event tree linking, partitioning, and editing sequences. Section 7 presents how accident sequences are generated, solved, quantified, and analyzed. Section 8 discusses the functions available for performing end state analysis. Section 9 explains how to modify data stored in a SAPHIRE database. Section 10 illustrates how to generate and customize reports. Section 11 covers SAPHIRE utility options to perform routine functions such as defining constant values, recovering databases, and loading data from external sources. Section 12 provides an overview of GEM's features and capabilities. Finally, Section 13 summarizes SAPHIRE's quality assurance process.

Page Last Reviewed/Updated Thursday, October 23, 2014