Implementation of the direct S ( α , β ) method in the KENO Monte Carlo code
The Monte Carlo code KENO contains thermal scattering data for a wide variety of thermal moderators. These data are processed from Evaluated Nuclear Data Files (ENDF) by AMPX and stored as double differential probability distribution functions. The method examined in this study uses S(α,β) probability distribution functions derived from the ENDF data files directly instead of being converted to double differential cross sections. This allows the size of the cross section data on the disk to be reduced substantially amount. KENO has also been updated to allow interpolation in temperature on these data so that problems can be run at any temperature. Results are shown for several simplified problems for a variety of moderators. In addition, benchmark models based on the KRITZ reactor in Sweden were run, and the results are compared with the previous versions of KENO without the direct S(α,β) method. Results from the direct S(α,β) method compare favorably with the original results obtained using the double differential cross sections. Finally, sampling the data increases the runtime of the Monte Carlo calculation, but memory usage is decreased substantially.
 Authors:

^{[1]};
^{[2]}
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
 Univ. of Tennessee, Knoxville, TN (United States)
 Publication Date:
 Grant/Contract Number:
 AC0500OR22725
 Type:
 Accepted Manuscript
 Journal Name:
 Annals of Nuclear Energy (Oxford)
 Additional Journal Information:
 Journal Name: Annals of Nuclear Energy (Oxford); Journal Volume: 101; Journal ID: ISSN 03064549
 Publisher:
 Elsevier
 Research Org:
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
 Sponsoring Org:
 USDOE National Nuclear Security Administration (NNSA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Monte Carlo; Direct S(α,β); Thermal scattering; KENO
 OSTI Identifier:
 1335339
Hart, Shane W. D., and Maldonado, G. Ivan. Implementation of the direct S(α,β) method in the KENO Monte Carlo code. United States: N. p.,
Web. doi:10.1016/j.anucene.2016.11.019.
Hart, Shane W. D., & Maldonado, G. Ivan. Implementation of the direct S(α,β) method in the KENO Monte Carlo code. United States. doi:10.1016/j.anucene.2016.11.019.
Hart, Shane W. D., and Maldonado, G. Ivan. 2016.
"Implementation of the direct S(α,β) method in the KENO Monte Carlo code". United States.
doi:10.1016/j.anucene.2016.11.019. https://www.osti.gov/servlets/purl/1335339.
@article{osti_1335339,
title = {Implementation of the direct S(α,β) method in the KENO Monte Carlo code},
author = {Hart, Shane W. D. and Maldonado, G. Ivan},
abstractNote = {The Monte Carlo code KENO contains thermal scattering data for a wide variety of thermal moderators. These data are processed from Evaluated Nuclear Data Files (ENDF) by AMPX and stored as double differential probability distribution functions. The method examined in this study uses S(α,β) probability distribution functions derived from the ENDF data files directly instead of being converted to double differential cross sections. This allows the size of the cross section data on the disk to be reduced substantially amount. KENO has also been updated to allow interpolation in temperature on these data so that problems can be run at any temperature. Results are shown for several simplified problems for a variety of moderators. In addition, benchmark models based on the KRITZ reactor in Sweden were run, and the results are compared with the previous versions of KENO without the direct S(α,β) method. Results from the direct S(α,β) method compare favorably with the original results obtained using the double differential cross sections. Finally, sampling the data increases the runtime of the Monte Carlo calculation, but memory usage is decreased substantially.},
doi = {10.1016/j.anucene.2016.11.019},
journal = {Annals of Nuclear Energy (Oxford)},
number = ,
volume = 101,
place = {United States},
year = {2016},
month = {11}
}