## RSICC CODE PACKAGE PSR-582

### 1. NAME AND TITLE

BURD - Bayesian Estimation in Data Analysis
of Probabilistic Safety Assessment.

### 2. CONTRIBUTORS

Korea Atomic Energy Research Institute,
Daejeon, Republic of Korea through the Nuclear Energy Agency Data Bank,
Issy-les-Moulineaux, France.

### 3. CODING LANGUAGE AND COMPUTER

VISUAL BASIC; PC/Windows 98 SE, NT,
2000, ME XP (P00582IBMPC00).

### 4. NATURE OF PROBLEM SOLVED

BURD (Bayesian Update for
Reliability Data) is a simple code that can be used to obtain a Bayesian
estimate easily in the data analysis of PSA (Probabilistic Safety Assessment).
According to the Bayes' theorem, basically, the code facilitates calculations
of posterior distribution given the prior and the likelihood (evidence)
distributions.

The distinctive features of the program, BURD, are the following:

·
The input consists of the prior and likelihood functions that can
be chosen from the built-in statistical distributions.

·
The available prior distributions are uniform, Jeffrey's non
informative, beta, gamma, and log-normal that are most-frequently used in
performing PSA.

·
For likelihood function, the user can choose from four
statistical distributions, e.g., beta, gamma, binomial and poisson.

·
A simultaneous graphic display of the prior and posterior
distributions facilitate an intuitive interpretation of the results.

·
Export facilities for the graphic display screen and text-type
outputs are available.

·
Three options for treating zero-evidence data are provided.

·
Automatic setup of an integral calculus section for a Bayesian
updating.

### 5. METHOD OF SOLUTION

The posterior distribution is
estimated in accordance with the Bayes' theorem, given the prior and the
likelihood (evidence) distributions.

### 6. RESTRICTIONS OR LIMITATIONS

The accuracy of the results depends
on the calculational error of the statistical function library in MS Excel.

Visual Basic 6 was used. The
program BURD makes extensive use of the function library of MS Excel to
calculate posterior distributions, and Graphic server 4.5 version to provide a
convenient user interface. There are no related databases or edited
input/output files because BURD is considered as a calculator.

### 7. TYPICAL RUNNING TIME

The running time is dependent on
the size of the mesh and the capacity of PC. Most of the BURD examples take
within a few seconds.

### 8. COMPUTER HARDWARE REQUIREMENTS

IBM PC.

### 9. COMPUTER SOFTWARE REQUIREMENTS

PC Windows 98 SE, NT, 2000, ME and
XP.

### 10. REFERENCES

**Included
Documentation:**

Informal
Memo (KAERI-ISA-MEMO-PSA-2001-024) March 21, 2002.

### 11. CONTENTS OF CODE PACKAGE

The package is transmitted on one
CD with the documentation and source code..

### 12. DATE OF ABSTRACT

April 2013.

**KEYWORDS**: BAYESIAN
METHOD, PROBABILITY SAFETY ANALYSIS