PERSENT 11.2892: Perturbation and Sensitivity Code for Assembly Homogenized Multi-group Transport Problems.
Auxiliary Codes::
DIF3D 11.2892: Solves 1-D, 2-D, and 3-D finite-difference diffusion theory problems. VARIANT 11.0: Solves VARIational Anisotropic Nodal Transport problems
Argonne National Laboratory, Argonne, Illinois.
Fortran 90 source code for Linux PCs, MacOSX and SUN, (C00823MNYCPS02).
The PERSENT 11.2892 release is a new package which allows users to perform perturbation and sensitivity calculations on conventional assembly homogenized diffusion and transport problems. It is built around the VARIANT option of DIF3D (included). For perturbation, calculations can be done that consider typical material and cross section perturbations. For sensitivity calculations, users can compute eigenvalue, reaction rate, reaction rate ratio, power fraction, reactivity worth, prompt neutron lifetime, and beta effective to the microscopic reactions: gamma, alpha, proton, deuteron, tritium fission, nu, and P0 & P1 scatter cross sections.
Related and Auxiliary Programs: DIF3D reads and writes the standard interface files specified by the Committee on Computer Code Coordination (CCCC). Parts of DIF3D are embedded into PERSENT and thus it is included in this distribution. Additional utilities are provided to allow users to better use the existing software package including a basic visualization capability called DIF3D_TO_VTK which generates input files for VISIT or Paraview. For PERSENT, additional utility programs are provided to allow users to verify their results with direct eigenvalue perturbations by manual adjustments to the cross section data.
PERSENT provides the conventional first order perturbation and generalized perturbation approaches. For sensitivity calculations, equivalent generalized perturbation theory is used for reactivity worth and eigenvalue sensitivities while all other sensitivities use the sensitivity functional approach. The latest version of DIF3D is included and must be made available as the VARIANT operator of DIF3D is built into the PERSENT code for the perturbation and sensitivity options.
The perturbation theory calculations are generally robust and have been rigorously verified. The sensitivity calculations are an initial version which has been validated to work properly, but little consideration of performance was taken and users have noted the relatively high costs compared with existing tools (mostly 2D). These issues are slated to be resolved in PERSENT 12.0. All non - U.S. government funded license requests should be redirected to nera-software@anl.gov
VARI3D is provided as is with no warranty of multiple platform usability. It carries out perturbation calculations on all geometries of the finite difference diffusion option of DIF3D. It also carries out sensitivity calculations on the R-Z finite difference diffusion option of DIF3D. Only basic support will be provided for VARI3D. All input options of VARI3D have not been tested.
PERSENT: Most of the 16 test cases complete in less than a minute with a combined total time of 25 minutes for the benchmark suite where benchmarks 8 and 15 take 20 minutes together due to the problem size. The existing coding only operates on a single core with no parallelism or threading noting that we are working towards using limited threading for DIF3D 12.0. The outstanding performance issues for the sensitivity calculations are also going to be addressed in PERSENT 12.0. The PERSENT code was designed to operate in "no work" mode which allows users to generate the DIF3D inputs for manual execution of the work in parallel. Similarly, the expensive sensitivity calculations can typically be broken into multiple individual tasks that can be run in parallel to effectively reduce the computational effort.
VARI3D: All 6 test cases complete in less than 4 minutes.
External data storage must be available for a large number of output files if a large number of perturbation/sensitivity calculations are to be done. If insufficient memory resources are available then large random access scratch files may be created which are associated with the individual response matrices and vectors used for the solution. We strongly recommend mounting a separate hard drive as /tmp and running all jobs from that location to prevent network drive issues. The remaining binary files are sequential access files with formatted or unformatted record types.
No special requirements are made on the operating system. The included installation procedure requires a Fortran 90 (or newer) compiler and we impose compile-time fixed memory size on the DIF3D code (see installation README.txt). The PERSENT coding is mostly F90+ with a focus on maintaining simplicity of the coding for portability.
S M. A. Smith, C. Adams, W. S. Yang, and E. E. Lewis, "VARI3D & PERSENT: Perturbation and Sensitivity Analysis", ANL/NE-13/8, Argonne National Laboratory, Argonne, IL (2013).
K. L. Derstine, DIF3D: A Code to Solve One-, Two-, and Three-Dimensional Finite-Difference Diffusion Theory Problems, ANL-82-64, Argonne National Laboratory, Argonne, IL (1984).
R. D. Lawrence, The DIF3D Nodal Neutronics Option for Two- and Three-Dimensional Diffusion Theory Calculations in Hexagonal Geometry, ANL-83-1, Argonne National Laboratory, Argonne, IL (1983).
G. Palmiotti, E. E. Lewis, and C. B. Carrico, VARIANT: VARIational Anisotropic Nodal Transport for Multidimensional Cartesian and Hexagonal Geometry Calculation, ANL-95/40, Argonne National Laboratory, Argonne, IL (October 1995).
C. H. Adams, et.al., The Utility Subroutine Package Used by Applied Physics Division Export Codes, ANL-83-3, Argonne National Laboratory, Argonne, IL (May 1992).
D. O’Dell, “Standard Interface Files and Procedures for Reactor Physics Codes, Version IV,” LA-6941-MS, Los Alamos Scientific Laboratory (September 1977).
Included is a Unix tar file which includes source code, code documentation (in pdf format), sample problem input and output, code dependent BCD and binary card image file descriptions, python scripts, a README installation file, an updated manual describing the PERSENT code and revisions to the Variant option.
February 2014
KEYWORDS: PERTURBATION; SENSITIVITY; TRANSPORT, MULTIGROUP; CRITICALITY CALCULATIONS; CCCC INTERFACE FORMAT; REACTOR PHYSICS