RSICC CODE PACKAGE PSR-386

1. NAME AND TITLE

IRRAS 4.16: Code System to Calculate Integrated Reliability and Risk Analysis.

2. CONTRIBUTOR

EG&G Idaho, Inc., Idaho Falls, Idaho, through the Energy Science and Technology Software Center, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

MODULA-2; IBM PC; IBM PC/AT (P00386IBMPC04).

4. NATURE OF PROBLEM SOLVED

IRRAS Version 4.16, the latest in a series (2.0, 2.5, 4.0, 4.15), is a program developed for the purpose of performing those functions necessary to create and analyze a complete Probabilistic Risk Assessment (PRA). This program includes functions to allow the user to create event trees and fault trees, to define accident sequences and basic event failure data, to solve system and accident sequence fault trees, to quantify cut sets, and to perform uncertainty analysis on the results. Also included in this program are features to allow the analyst to generate reports and displays that can be used to document the results of an analysis. Since this software is a very detailed technical tool, the user of this program should be familiar with PRA concepts and the methods used to perform these analyses. IRRAS Version 4.16 is the latest in the stand-alone IRRAS series (2.0, 2.5, 4.0, 4.15). Be sure to review the PSR-405/ SAPHIRE 7.06 package which was released in January 2000 and includes three programs: the Integrated Reliability and Risk Analysis System (IRRAS), the System Analysis and Risk Assessment (SARA) system, the Models And Results Database (MAR-D) system, and the Fault tree, Event tree and P&ID (FEP) editors.

5. METHOD OF SOLUTION

IRRAS is written entirely in MODULA-2 and uses an integrated commercial graphics package to interactively construct and edit fault trees. The fault tree solving methods used are industry recognized top down algorithms. For quantification, the program uses standard methods to propagate the failure information through the generated cut sets.

6. RESTRICTIONS OR LIMITATIONS

Due to the complexity of and the variety of ways a fault tree can be defined it is difficult to define limits on the complexity of the problem solved by this software. It is, however, capable of solving a substantial fault tree due to efficient methods. At this time, the software can efficiently solve problems as large as other software currently used on mainframe computers.

7. TYPICAL RUNNING TIME

IRRAS running times are a function of the problem to be solved and the actions performed by the user.

8. COMPUTER HARDWARE REQUIREMENTS

IBM-PC/XT/AT/PS-2 or 100% compatible. The PC must have a 640K of RAM, an EGA/VGA compatible monitor and display adaptor, and a hard disk with at least 10 megabytes of free space. A numeric math co-processor and a mouse are highly recommended.

9. COMPUTER SOFTWARE REQUIREMENTS

IRRAS 4.16 was developed under DOS 5.0. It was executed at RSICC on a Pentium II/266 machine running Windows95. Source files are not included; only executable files are available. Version 4.16 was submitted to ESTSC in July 1993. It was later transferred to RSICC and released in February 2002. There have been no modifications to the package since its initial release in 1993.

10. REFERENCES

a. Included with Package:

K.D. Russell, N.L. Skinner and R.L. VanHorn, "Integrated Reliability and Risk Analysis System (IRRAS) Version 4.0 Tutorial," NUREG/CR-5813 (EGG-2664) Vol. 2 (October 1992).

b. Background Information:

T.W. Bolander, M.B. Calley, E.L. Capps, W.J. Galyean, J.L. Jones, S.D. Novak, C.L. Smith, A.D. Trusty, R.L. VanHorn, L.M. Wolfram, and S.L. Zeigler, "Verification and Validation of the SAPHIRE Version 4.0 PRA Software Package," NUREG/CR-6145 (February 1994).

K.D. Russell, M.K. McKay, M.B. Sattison, N.L. Skinner, S.T. Wood, D.M. Rasmuson, "Integrated Reliability and Risk Analysis System (IRRAS) Version 4.0 Reference Manual," NUREG/CR-5813 (EGG-2664) Vol. 1 (January 1992).

K.D. Russell, M.B. Sattison, and D.M. Rasmuson, "Integrated Reliability and Risk Analysis System (IRRAS) Version 2.0 User's Guide," NUREG/CR-5111, EGG-2535, (June 1990).

K.D. Russell, M.K. McKay, M.B. Sattison, N.L. Skinner, S. T. Wood, and D. M. Rasmuson, "Integrated Reliability and Risk Analysis System (IRRAS) Version 2.5, Reference Manual," NUREG/CR-5300, EGG-2613, Vol. 1 (March 1991).

11. CONTENTS OF CODE PACKAGE

Included are the reference document in 10.a and executables, which are distributed on three DS/HD diskettes. Source files are not included.

12. DATE OF ABSTRACT

February 2002. (Software was developed in 1993.)

KEYWORDS: PROBABILITY SAFETY ANALYSIS; RISK ASSESSMENT