1. NAME AND TITLE

TEMAC: Top Event Matrix Analysis Code System.
 

2. CONTRIBUTORS

Sandia National Laboratories, Albuquerque, New Mexico through the Energy Science and Technology Software Center, Oak Ridge, Tennessee.
 

3. CODING LANGUAGE AND COMPUTER

Fortran 77; DEC Vax8650 (P00468D0VAX00).
 

4. NATURE OF PROBLEM SOLVED

TEMAC is designed to permit the user to easily estimate risk and to perform sensitivity and uncertainty analyses with a Boolean expression such as produced by the SETS computer program. SETS produces a mathematical representation of a fault tree used to model system unavailability. In the terminology of the TEMAC program, such a mathematical representation is referred to as a top event. The analysis of risk involves the estimation of the magnitude of risk, the sensitivity of risk estimates to base event probabilities and initiating event frequencies, and the quantification of the uncertainty in the risk estimates.
 

5. METHOD OF SOLUTION

Sensitivity and uncertainty analyses associated with top events involve mathematical operations on the corresponding Boolean expression for the top event, as well as repeated evaluations of the top event in a Monte Carlo fashion. TEMAC employs a general matrix approach which provides a convenient general form for Boolean expressions, is computationally efficient, and allows large problems to be analyzed.
 

6. RESTRICTIONS OR LIMITATIONS

Maxima of 4000 cut sets, 500 events, 500 values in a Monte Carlo sample, and 16 characters in an event name. These restrictions are implemented through the FORTRAN 77 PARAMETER statement.
 

7. TYPICAL RUNNING TIME

NESC executed each of the sample problems in less than 5 CPU seconds on a DEC VAX11/785.
 

8. COMPUTER HARDWARE REQUIREMENTS

3.6 Mbytes of virtual memory are required for execution.
 

9. COMPUTER SOFTWARE REQUIREMENTS

VMS 4.3; VMS 4.5 and a Fortran 77 compiler.
 

10. REFERENCES

a) Included with package:

L. Eyberger, "TEMAC, NESC No. 1084, TEMAC Tape Description and Implementation Information," NESC Note 87-99 (September 21, 1987).

R. L. Iman and M. J. Shortencarier, "A User's Guide for the Top Event Matrix Analysis Code (TEMAC)," NUREG/CR-4598, SAND86-0960 (August 1986).
 

b) Background information:

R. L. Iman and M. J. Shortencarier, "A FORTRAN 77 Program and User's Guide for the Generation of Latin Hypercube and Random Samples for Use With Computer Models," NUREG/CR-3624 (SAND83-2365) 9March 1984).

R. B. Worrell, "SETS Reference Manual," NUREG/CR-4213 (SAND83-2675) (May 1985).
 

11. CONTENTS OF CODE PACKAGE

Included in the package is the referenced document in (10.a) and one DOS-formatted 3.5" diskette which includes the source program and test case input and output. No executables are provided with the package.
 

12. DATE OF ABSTRACT

June 2000.
 

KEYWORDS: MONTE CARLO; RISK ASSESSMENT; SENSITIVITY ANALYSIS