Generating and Validation of Thermal Neutron Scattering Library for MCNP

A continuous neutron transport library for MCNP and several temperature-dependent multigroup cross section libraries with Bondarenko self-shielded factors based on ENDF/B-Ⅶ.0 were generated in former work. In the work the thermal S(α, β) tables for MCNP code were converted from the thermal neutron scattering sublibrary of ENDF/B-Ⅶ.0 using NJOY program. The available thermal S(α, β) library named sab2002 (from ENDF/B-Ⅵ) released with MCNP were investigated and compared with the self-produced library thb70, and some significant improvements of important medias, such as H in H₂O and D in D₂O, were presented. Forty-eight critical benchmark models were selected to calculate the k_eff using sab2002 and thb70, respectively. The results show that there is a not too much difference (65 pcm averagely) between the two libraries.