PARET-ANL(NESC): Code System to Predict Consequences of Nondestructive Accidents in Research and Test Reactor Cores
Argonne National Laboratory, Argonne, Illinois, through the Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France
Unix, Linux and Windows (P00565MNYCP00).
NEADB ID: NESC0555/03.
This program is designed for use in predicting the course and consequences of nondestructive reactivity accidents in research and test reactor cores. It can be used for both steady-state and transient analysis.
PARET provides a hydrodynamic and point kinetics capability. The core can be represented by four or fewer regions; each having different power generation, coolant mass flow rate, and hydraulic parameters as represented by a single fuel pin or plate with associated coolant channel. The heat transfer in each fuel element is computed on the basis of a one-dimensional conduction solution in each of up to a maximum of 21 axial sections. The hydrodynamics solution is also one-dimensional for each channel at each time node. The heat transfer may take place by natural or forced convection, nucleate, transition, or stable film boiling. The coolant is allowed to range from subcooled liquid, through the two-phase regime, up to and including superheated steam, and coolant flow reversal is allowed. PARET-ANL also has an optional “voiding model” which estimates the voiding produced by subcooled boiling.
The PARET model is subject to several recognized limitations which may limit the applicability in any specific situation, depending on the nature of the transient under consideration. The code employs steady-state heat transfer correlations throughout, possibly being unrealistic in certain transient situations. Any complete description of a severe transient must include provision for some sort of thermal or hydraulic crisis. PARET is limited in predicting such a crisis by the fact that it employs only steady-state correlations; no transient correlations with demonstrated reliability were developed. Accurate description of hydraulic instability depends upon accurate calculation of transient pressure and flow fluctuations. PARET is limited in this respect because it employs an incompressible model and a simplified void volume generation equation. Also, the magnitude of local pressures predicted to accompany coolant expulsion is strongly affected by the number of axial sections chosen in the computations. As a result, the hydrodynamic output should be interpreted as a qualitative indication of a possible crisis rather than a reliable quantitative prediction. PARET is not applicable to either destructive excursions or situations in which there is a space-time effect in neutron flux.
Running time is problem specific; however, the sample problem requires less than 18 seconds of CPU time to process 320 time-steps with 2 channels on an IBM3033 from testing at the NEADB. Note: PARET-ANL(NESC) was not tested at RSICC.
This code should work on any platform with a Fortran 77 compatible compiler. Editing will be necessary.
A Fortran 77 compiler is required.
a. included in documentation:
A. Strecok, “PARET-ANL Tape Description and Implementation Information,” NESC Note 85-02 (October 4, 1984).
W. L. Woodruff, “The PARET Code and the Analysis of the SPERT I Transients,” (ANL Paper).
W. L. Woodruff, “A User Guide for the Current ANL Version of the PARET Code,” (ANL Paper).
C. F. Obenchain, “PARET - A Program for the Analysis of Reactor Transients,” IDO-17282 (January 1969).
Excerpts from NRTS, Environmental Subroutine Manual. (December 1972).
ANL-AMD System/360 Library Subroutine: ANL Q054S Subroutine. (August 1, 1973).
b. background references:
C. F. Obenchain, “PARET - A Program for the Analysis of Reactor Transients,” IDO-17282 (January 1969).
W. L. Woodruff, “A Kinetics and Thermal-Hydraulics Capability for the Analysis of Research Reactors,” Nucl. Tech., 64 (February 1984).
The package includes a self-extracting compressed Windows file that includes Fortran source files, test case, and the documents referenced in 10.a. No executables are included.
October 2011.
KEYWORDS: HEAT TRANSFER; REACTOR SAFETY; THERMAL HYDRAULICS; MICROCOMPUTER; WORKSTATION