RSICC CODE PACKAGE PSR-441

1. NAME AND TITLE

PSDREC: Code System for Power Spectral Density Recognition Continuous On-line Reactor Surveillance.

2. CONTRIBUTORS

Oak Ridge National Laboratory, Oak Ridge, Tennessee through the Energy Science and Technology Software Center, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

Fortran IV (85%) and MACRO (15%); DEC PDP11/34 (P00441DP01100).

4. NATURE OF PROBLEM SOLVED

PSDREC is a statistically-based pattern recognition system developed for continuous, on-line, unattended surveillance of dynamic reactor signals. The system provides a detailed record of the power spectral density values (PSDs) of the signals and their statistical characteristics. PSD measurements on process signals are the performance signatures that characterize the health of the monitored equipment. PSDREC can monitor 16 signals, use 15 signals in determining the operational state of the reactor, and store traceable historical data on suspect conditions. The PSDREC surveillance system uses four types of power spectral densities. These are formed over time spans. PSDZ is the short-term trend spectrum used to detect rapidly occurring signals. Each of the other three spectra is formed by ensemble averaging different numbers of PSDZ spectra. PSDB, the baseline spectrum, is formed over the longest time span. It is formed only once for each operational state. PSDT and PSDC are the long-term reference and candidate trend spectra which are formed over a relatively long time span and are used to reflect slow changes in the signal. PSDREC was the thrid generation of this computerized surveillance system and superseded PSDREA and PSDREG.

5. METHOD OF SOLUTION

PSDREC uses statistical methods to provide a quantitative basis for automating the detection of suspect conditions. Through statistical comparison of current PSDs with past baseline PSDs, the system can detect changes in the monitored reactor signals. The historical record of PSDs is cataloged along with information which reflects the current operating state of the reactor, since these conditions may affect the PSD signatures from monitored signals.

6. RESTRICTIONS OR LIMITATIONS

Because of 1988 software limitations, PSDREC can monitor a maximum of four signals simultaneously.

7. TYPICAL RUNNING TIME

PSDREC runs continuously.

8. COMPUTER HARDWARE REQUIREMENTS

PSDREC was implemented on a DEC PDP11/34A minicomputer with 96 Kwords of semiconductor memory, 7.5 megabytes of disk storage, a completely computer controlled signal conditioning data acquisition unit, and a floating point processor (FPP).

9. COMPUTER SOFTWARE REQUIREMENTS

PSDREC ran under the RT-11 V4.0 operating system and is written in Fortran IV and Macro. The PDP-11 object files and executable are included in the package, but they can only be used on a PDP 11. The source files would require modification to run on other computers. The Fortran source was compiled by NESC in July 1988 on a DEC VAX11/785. No testing was performed, and no changes were made when the files were transferred to RSICC and released in March 2001.

10. REFERENCES

a) Included in the documentation:

C.M. Smith, "A Description of the Hardware and Software of the Power Spectral Density Recognition (PSDREC) Continuous On-Line Reactor Surveillance System (California Distribution), Volumes 1 and 2," NUREG/CR-3439, Vol. 1 & 2 (ORNL/TM-8862/V1 & V2), (December 1983).

L. Reed, "PSDREC, NESC No. 1107, PSDREC Tape Description," NESC Note 89-31 (February 21, 1989).

b) background reference:

W.H. Sides, Jr. and K.R. Piety, Automated Pattern Recognition System for Noise Analysis, Transactions of the American Nuclear Society, 34, 720-722 (1980).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents in 10.a and a DS/HD diskette which contains a self-extracting compressed DOS file including Fortran and Macro source files and a PDP-11 executable.

12. DATE OF ABSTRACT

March 2001.

KEYWORD: REACTOR MONITORING.