SAPHIRE technical reference manual: IRRAS/SARA Version 4.0

Technical Report · Fri Jan 01 04:00:00 EST 1993

DOI:https://doi.org/10.2172/10120495· OSTI ID:10120495

Russell, K D; Atwood, C L; Sattison, M B ^[1]; Rasmuson, D M ^[2]

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1. EG and G Idaho, Inc., Idaho Falls, ID (United States)
2. Nuclear Regulatory Commission, Washington, DC (United States)

This report provides information on the principles used in the construction and operation of Version 4.0 of the Integrated Reliability and Risk Analysis System (IRRAS) and the System Analysis and Risk Assessment (SARA) system. It summarizes the fundamental mathematical concepts of sets and logic, fault trees, and probability. The report then describes the algorithms that these programs use 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 are appropriate under various assumptions concerning repairability and mission time. It defines the measures of basic event importance that these programs can calculate. The report gives an overview of uncertainty analysis using simple Monte Carlo sampling or Latin Hypercube sampling, and states the algorithms used by these programs to generate random basic event probabilities from various distributions. Further references are given, and a detailed example of the reduction and quantification of a simple fault tree is provided in an appendix.

• Research Organization: Nuclear Regulatory Commission, Washington, DC (United States). Div. of Safety Issue Resolution; EG and G Idaho, Inc., Idaho Falls, ID (United States)
• Sponsoring Organization: Nuclear Regulatory Commission, Washington, DC (United States)
• DOE Contract Number: AC07-76ID01570
• OSTI ID: 10120495
• Report Number(s): NUREG/CR--5964; EGG--2692; ON: TI93006910
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220900
99 GENERAL AND MISCELLANEOUS
990200
ALGORITHMS
FAULT TREE ANALYSIS
I CODES
MANUALS
MATHEMATICAL LOGIC
MATHEMATICAL MODELS
MATHEMATICS AND COMPUTERS
PROBABILITY
REACTOR SAFETY
RELIABILITY
RISK ASSESSMENT
S CODES