**RSICC CODE PACKAGE PSR-468**

**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