CCC-0654 VENTURE-PC 1.1.

1. NAME OR DESIGNATION OF PROGRAM:   VENTURE-PC 1.1.

3. DESCRIPTION OF PROGRAM OR FUNCTION

The VENTURE program solves the usual neutronics eigenvalue, adjoint, fixed source, and criticality search problems. It treats up to three dimensions, maps power density, and does first-order perturbation analysis at the macroscopic cross section level. The BURNER code solves the nuclide chain equations to estimate the nuclide concentrations and burnup at the end of an exposure time or after a shutdown period.

This package is based on the CCC-459/BOLD VENTURE IV code system developed at Oak Ridge National Laboratory. In January 1989 the University of Cincinnati contributed the first VENTURE-PC package to RSICC's collection. It was a subset of the mainframe version consisting of the VENTURE and BURNER modules plus several processing modules. VENTURE-PC was distributed as CCC-459 until July 1997 when a new version (with updated source code compatible with newer FORTRAN-77 compilers, some revisions, and extensions to solve much larger problems) was contributed by Argonne National Laboratory. The principle code modules included in the VENTURE-PC system are:

VENTURE: Multigroup neutronics finite-difference diffusion theory.
BURNER: Depletion calculation for reactor core analysis.
Other modules within VENTURE-PC are:
DVENTR: Venture input processor
DCRSPR: Neutron cross section processor
DUTLIN: Control file (CNTRL) input processor
DCMACR: Citation format cross section input processor
CRXSPR: Cross section processor
DENMAN: Fuel repositioning module.

In August of 1999, Argonne again contributed an updated version of the code which overcomes problem size constraints caused by binary record length limits inherent to the Fortran 90 compiler. The need for long records is detected and avoided by sub-blocking them. Also, the latest Fortran 95 compiler offers substantial speed gains on the newest processors. The source code is updated to be compatible with either Fortran 90 or Fortran 95. In August 2002, the package was updated with the addition of several sample problems, a new Windows executable, and a new Linux version.

4. METHODS

The VENTURE module applies the finite-difference diffusion or a simple P1 approximation. VENTURE uses an outer-inner iteration scheme with several different data handling methods. Overrelaxation is applied to the inner and outer iterations, and succeeding flux iterates may be accelerated with the Chebychev process. The BURNER code uses a difference formulation based on average generation rates, or a matrix exponential formulation, to approximate the solution of the coupled burnup differential equations, or an explicit solution for simply coupled nuclide chains. Space-dependence is included by working with zone averaged fluxes.

The first user input data line must be the control module name used for the run. Venture-PC reads these data in CCCC ISOTXS format. AMPX working format libraries can be translated to ISOTXS format using the CONTAC module of AMPX-77. Alternately PSR-286/COMBINE-PC can be used to process ISOTXS data.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The executable is limited to a core container of 3,000,000 words, but it can be recompiled for much larger sizes due to the flat memory model of the Lahey Fortran 90 32-bit compiler. Prior versions of the code were unable to solve large mesh problems because of LF90 compiler limits on binary record lengths (<32,767 bytes). These records now are blocked, eliminating this restriction on problem size. Binary records created by the Fortran 95 compiler have a revised format from that created by the Fortran 90 compiler, in order to address a much larger record size limit. Pre-existing binary files written by any code compiled under Fortran 90 cannot be read by the code compiled under Fortran 95. Such files must be converted from 90 to 95 and vice-versa using Lahey-supplied tools that come with the compiler.

6. TYPICAL RUNNING TIME

Running times are problem-dependent, as well as processor-speed-dependent. On a dual-processor Pentium II 300 MHz system with 128 megabytes of memory under Windows NT, sample problem THREEDX4.INP, which has a 68 x 68 x 57 mesh and 2 neutron groups, was completed in 6.0 minutes. The same case was completed in 12.7 minutes on a 233 MHz Pentium MMX system with 48 megabytes of memory under Windows 95.

10. REFERENCES

- D.R. Vondy, T.B. Fowler, G.W. Cunningham:
  The Bold Venture Computation System for Nuclear Reactor Core
  Analysis, Version III.  ORNL-5711 (June 1981)
- D.R. Vondy, T.B. Fowler, G.W. Cunningham, L.M. Petrie:
  A Computation System for Nuclear Reactor Core Analysis.
  ORNL-5158 (April 1977)
- D.R. Vondy, T.B. Fowler, G.W. Cunningham:
  VENTURE: A Code Block for Solving Multigroup Neutronics Problems
  Applying the Finite-Difference Diffusion-Theory Approximation to
  Neutron Transport, Version III.  ORNL-5062/R1 (November 1977)
- D. R. Vondy, G.W. Cunningham:
  Exposure Calculation Code Module for Reactor Core Analysis:
  BURNER.   ORNL-5180 (February 1979)
- T.W. Medlin, K.L. Hill, G.L. Johnson, J.E. Jones, D.R. Vondy:
  Fuel Management Positioning and Accounting Module: Fuelmang
  Version V1.11.   ORNL-5718 (January 1982)
- D.R. Vondy, T.B. Fowler:
  The Code PERTUBAT for Processing Neutron Diffusion Theory
  Neutronics Results for Perturbation Analyses.
  ORNL-5376 (March 1978)
- D.R. Vondy, T.B. Fowler:
  RODMOND - A Code for Control Rod Positioning.
  ORNL-5466 (November 1978)
- J.R. White:
  The DEPTH-CHARGE Static and Time Dependent Perturbation/
  Sensitivity System for Nuclear Reactor Core Analysis.
  ORNL/CSD-78/R1 (May 1984)
- D.R. Vondy, T.B. Fowler:
  Reference Test Problems for the Venture Neutronics and Related
  Computer Codes.  ORNL/TM-5887 (August 1977)
- G.E. Bosler, R.D. O'Dell, W.M. Resnik:
  LASIP-III, A Generalized Processor for Standard Interface Files.
  LA-6280-MS (April 1976)

- A. Shapiro, H. C. Huria, and K. W. Cho:
VENTURE-PC Manual, A Multidimensional Multigroup Neutron
Diffusion Code System, Version 2," EGG-2582,
University of Cincinnati (January 1990).
- A. P. Olson:
Availability and Benchmarking of VENTURE-PC as Modified by ANL
Argonne National Lab memo (April 8, 1997).
- A. P. Olson:
Availability and Benchmarking of VENTURE-PC, Version 1.1
(Fortran 95 or Fortran 90)," Argonne National Lab memo (August 30, 1999).

11. HARDWARE REQUIREMENTS

The package runs on Pentium III or Pentium IV personal computers. The resource needs are the same as those of the Windows operating system. Approximately 75MB of disk space is required to expand the master and run test cases.

13. SOFTWARE REQUIREMENTS

The Windows distribution contains 2 executables. The newer executable is optimized for Pentium IV. It was compiled with Lahey/Fujitsu Fortran 95 V5.70b and was tested in a DOS window of Windows2000 and WindowsXP. The other executable was created in 1999 using Lahey Fortran 90 V4.50h and runs in a DOS window on Windows95/98/NT systems. This executable should be run on Pentium III computers and older.

The Linux distribution includes an executable compiled with the Lahey/Fujitsu Fortran 95 Version 6.10a compiler for Linux. This executable is optimized for Pentium IV and was tested on RedHat Linux 7; it will not run under RedHat Linux 6.1. Other Linux variants might be compatible if they include kernel version 2.2 or later and libc version 2.1.1 or later.

15. NAME AND ESTABLISHMENT OF AUTHORS

Contributed by:
                Radiation Safety Information Computational Center
                Oak Ridge National Laboratory
                Oak Ridge, Tennessee, U. S. A.

Developed by:
                University of Cincinnati
                Cincinnati, Ohio, U. S. A.

                Argonne National Laboratory
                Argonne, Illinois, U. S. A.

654PC586.TXT List of files
C654.PDF Documentation
Readme.rsi RSICC readme file
Documentation directory
Inputs directory
Outputs directory
Source directory
LF90.EER Error file
Readme.txt Information file
ven570b.exe Executable (for Windows)
VEN902.EXE Executable (for Windows)
venlinux Executable for linux