NAME OR DESIGNATION OF PROGRAM, COMPUTER, DESCRIPTION OF PROBLEM OR FUNCTION, METHOD OF SOLUTION, RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM, TYPICAL RUNNING TIME, UNUSUAL FEATURES OF THE PROGRAM, RELATED AND AUXILIARY PROGRAMS, STATUS, REFERENCES, MACHINE REQUIREMENTS, LANGUAGE, OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED, OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHOR, MATERIAL, CATEGORIES

[ top ]

[ top ]

To submit a request, click below on the link of the version you wish to order.
Only liaison officers are authorised to submit online requests. Rules for requesters are
available here.

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 |

[ top ]

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.

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.

[ top ]

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.

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.

[ top ]

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.

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.

[ top ]

[ top ]

[ top ]

[ top ]

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.

- 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).

[ top ]

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.

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.

[ top ]

[ top ]

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.

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.

[ top ]

[ top ]

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 |

[ top ]

- F. Space - Time Kinetics, Coupled Neutronics - Hydrodynamics - Thermodynamics

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