Simplified 1D and 2D Sn transport for Nuclear engineering applications written mostly in python.

Solves the steady state neutron balance for multiplying and non-multiplying systems.

Supports triangular unstructured meshes generated by GMSH.

Currently uses continuous Galerkin FE technique for spatial discretization. Plan to move to DG methods.

Depends

• GMSH >=2.8.5
• numpy >=1.10
• scipy
• h5py

Optional Depends

• matplotlib (plotting)
• pyeVTK (2D plotting)
• periodictable
• mechanize (for automated XS processing)
• NJOY (for XS libs)

Developer install:

python setup.py develop

To generate custom cross section files (.xs) first download endf/b-vii libraries from the LANL T2 website using the utility script in /spytran/utils:

$python2 endfcrawl.py

Next, run the NJOY batch script in /spytran/utils:

$./createXS.sh

This script will generate new .xs files in /spytran/utils/XS_default by default.

The default 10 energy group cross section library is located /spytran/materials/newXS. The default cross sections were generated at 300K.

Multigroup XS files for fissile isotopes are generated by the /spytran/utils/njoybatchGRPfis.sh script. Multigroup XS files for non-Fissile isotopes are generated by the /spytran/utils/njoybatchGRPnofis.sh script. The group structure, evaluation temperature, and assumed background energy spectrum can be adjusted in these scripts.

Doppler broadening is performed by the NJOY broadr module. Simple inf-media self shielding is implemented by f-factor lookup. See the 2d_pin example file for a self shielded material example (by default inf dilution xs used - but it is easy to switch on f-factor self shielding). Plan is to incorporate a region and energy dependent leakage cross section into the Bondarenko method in the future. See:

www.me.utexas.edu/~deinert/papers/jpne1610-dembia.pdf

1. Construct GMSH .geo file
2. Write input python script
3. Execute the python input script
4. Visualize

See /spytran/examples directory for 1D and 2D example decks. Corresponding GMSH geometry files are in /spytran/examplex/geometry.

Example input file execution:

$python2 2d_pin.py

• /spytran
  • drivers and solvers

  • /spytran/fe

    • finite element classes

  • /spytran/materials

    • material mixing routines and xs readers.

  • /spytran/utils

    • parsers and ordinate set generators
    • other extra code

  • /spytran/plotters

    • flux and skernel plotting functions.

  • /spytran/examples

    • 1 and 2D example input scripts

    • /spytran/examples/geometry

      • geometry inputs

William Gurecky