3. DESCRIPTION OF PROGRAM OR FUNCTION
BETA-S calculates beta-decay source terms and energy spectra in multigroup format for time-dependent radionuclide inventories of actinides, fission products, and activation products. Multigroup spectra may be calculated in any arbitrary energy-group structure. The code also calculates the total beta energy release rate from the sum of the average beta-ray energies as determined from the spectral distributions. BETA-S also provides users with an option to determine principal beta-decaying radionuclides contributing to each energy group. The SCALE code system must be installed on the computer before installing BETA-S, which requires the SCALE subroutine library and nuclide-inventory generation from the ORIGEN-S code. This release is compatible with SCALE Versions 5.0, 5.1 and 6.
The following enhancements were completed in this version:
- the BETA-S source code was converted to modern Fortran 90 standard
- dynamic memory allocation implemented
- the free-format input reading routines were replaced with reading modules in SCALE 5
- added the capability to obtain beta decay branching data from either a binary or card-image format ORIGEN data library (required for compatibility with ORIGEN-ARP)
- corrected an error associated with spectral calculation in highest energy group
- improved spectrum calculation by normalizing spectral energy to evaluated beta energy
- added capability to generate plot files compatible with PlotOPUS program.
Note that default input values were eliminated in this release, so all input variables are now needed. Some libraries now have different numbers of nuclides which can cause problems. To address this, the code now also works with either the card-image nuclear data library or a binary library (e.g., origen-arp). If the ORIGEN inventory file was generated using a binary library, BETAS should be required to use the same library when doing the spectrum calculation to make sure the library is consistent with the nuclide set.