Analysis of the Impact of Cross-sectional Data Discrepancies on the Effectiveness of Radiation Shielding Design Using Monte Carlo Codes

The effect of cross-sectional data discrepancies on the effectiveness of radiation shielding design has been investigated in this paper. The MCNP code with cross-sections from ENDF/B-V and ENDF/B-VII has been used to determine the gamma ray dose equivalent, H*(10), behind a lead glass shield enclosing a slow neutron source. It is observed that the radiative capture gamma ray dose behind the shield is higher when ENDF/B-V cross-sections are used compared to that produced by ENDF/B-VII cross-sections. The discrepancy is due to absence of energetic primary gamma rays when ENDF/B-VII is used. The results show that shielding design using ENDF/B-VII cross-sections could underestimate the shield by a fair margin and compromise safety. It is therefore necessary to consider more than one release of ENDF/B when using lead glass for shielding slow neutron capture gamma rays. The discrepancies need to be addressed in the next releases