last modified: 26-MAY-1981 | catalog | categories | new | search |

NESC0862 FX2-TH.

FX2-TH, 2-D MultiGroup Neutron Diffusion in X-Y, R-Z and R-Theta Geometry with Thermal Feedback

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1. NAME OR DESIGNATION OF PROGRAM:  FX2-TH.
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2. COMPUTERS
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Program name Package id Status Status date
FX2-TH NESC0862/01 Tested 26-MAY-1981

Machines used:

Package ID Orig. computer Test computer
NESC0862/01 IBM 3033 IBM 3033
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3. DESCRIPTION OF PROBLEM OR FUNCTION

FX2-TH solves the steady-state  and time-dependent two-dimensional multigroup neutron diffusion equations with thermal and hydraulic feedback. The following geometry options are available: x, r, x-y, r-z, theta-r, and triangular. FX2-TH contains two basic thermal and hydraulic models:  a simple adiabatic fuel temperature calculation and a more detailed  model consisting of an explicit representation of fuel pin, gap, clad, and coolant. FX2-TH allows feedback effects from both fuel temperature (Doppler) and coolant temperature (density) changes.
The code is designed for nuclear reactor analysis.
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4. METHOD OF SOLUTION

The multigroup diffusion equations are discretized in space using mesh-centered finite differences. The steady-state solution of these equations is found by accelerating a  fission source iteration through the use of Chebyshev polynomials. The neutron fluxes for each energy group at each power iteration are found using the successive line over-relaxation method. A consistent set of steady-state conditions is established by iterating between the steady-state neutronics and thermal-hydraulics equations. The time-dependent solution is then found using the improved quasistatic method. The shape calculations required by the quasistatic method utilize the same calculational methods as described above for the steady-state calculation.
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5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Variable dimen- sioning is used throughout the program so that computer storage requirements depend on a variety of problem parameters. The amount of memory required can range from 300K bytes for a small problem up to the maximum limit of computer storage for very large problems.
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6. TYPICAL RUNNING TIME

Running times are dependent on the number of  groups, number of mesh points, length of the transient, and amount of change in the problem variables as the transient progresses.
The NESC executed the sample problem in 6 minutes on an IBM3033.
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7. UNUSUAL FEATURES OF THE PROGRAM

Microscopic cross sections and delayed neutron data are specified in the CCCC formats, ISOTXS and DLAYXS, respectively. A disk editing capability is included.
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8. RELATED AND AUXILIARY PROGRAMS

Input microscopic cross sections and delayed neutron data may be generated using the MC**2-2 program  (NESC Abstract 355).
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9. STATUS
Package ID Status date Status
NESC0862/01 26-MAY-1981 Tested at NEADB
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10. REFERENCES

- R. Douglas O'Dell,
Standard Interface Files and Procedures for Reactor Physics Codes,    Version IV, LA-6941-MS.
- D.A. Meneley, Gary Leaf, A.J. Lindeman, T.A. Daly, and W.T. Sha,
  A Kinetics Model for Fast Reactor Analysis in Two Dimensions,
  Dynamics of Nuclear Systems, The University of Arizona Press,
  Tucson, Arizona, pp.483-500, 1972.
NESC0862/01, included references:
- R.A. Shober, T.A. Daly, and D.R. Ferguson:
  FX2-TH - A Two-dimensional Nuclear Reactor Kinetics Code with
  Thermal-Hydraulic Feedback
  ANL-78-97 (October 1978).
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11. MACHINE REQUIREMENTS

FX2-TH will dynamically allocate problem variables either on disk or in computer memory depending on the total amount of computer memory available. For any problem a certain minimum amount of memory is required; this amount is dependent on the size of the problem. In general, FX2-TH operates more efficiently if sufficient computer memory is available to retain most of the variables permanently. The sample problem executed by NESC required 900K bytes of memory.
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12. PROGRAMMING LANGUAGE(S) USED
Package ID Computer language
NESC0862/01 FORTRAN-IV
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13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  OS/370.
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14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

FX2-TH
may be compiled using either FORTRAN H or Extended compilers with OPT=2 optimization. Skeleton versions of standard routines as specified by the Committee of Computer Code Coordination (CCCC) and  in the document LA-6941-MS are part of the FX2-TH package. These standard routines are REED, RITE, LRED, LRIT, TIMER, and SEEK; they  may be replaced by suitable local environment routines for enhanced  operation.
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15. NAME AND ESTABLISHMENT OF AUTHOR

R.A.Shober and A. Daly
Applied Physics Division
D.R. Ferguson
Fast Reactor Safety Technical Management Center
Argonne National Laboratory
9700 South Cass Avenue
Argonne, Illinois 60439
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16. MATERIAL AVAILABLE
NESC0862/01
File name File description Records
NESC0862_01.001 INFORMATION FILE 103
NESC0862_01.002 FX2-TH FORTRAN SOURCE (F4,EBCDIC) 38175
NESC0862_01.003 FX2-TH ASSEMBLER SOURCE 547
NESC0862_01.004 OVERLAY CARDS 68
NESC0862_01.005 SAMPLE PROBLEM 3 INPUT DATA 283
NESC0862_01.006 A.ISO MICROSCOPIC CROSS SECTIONS 38
NESC0862_01.007 A.DLA DELAYED NEUTRON PARAMETERS 1
NESC0862_01.008 MANUAL DOCUMENTATION 4891
NESC0862_01.009 PRINTED OUTPUT OF SAMPLE PROBLEM 5885
NESC0862_01.010 JCL TO RUN FX2-TH AT NEA/DATA BANK 295
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17. CATEGORIES
  • F. Space - Time Kinetics, Coupled Neutronics - Hydrodynamics - Thermodynamics

Keywords: diffusion equations, feedback, hydraulics, kinetics, multigroup theory, thermal conduction, two-dimensional.