[en] The radiative neutron capture process plays an important role in Big Bang Nucleosynthesis (BBN) models. Recent measurements of the deuterium abundance in high-redshift hydrogen clouds have allowed a precise comparison of the light elemental abundances with BBN-model predictions. These measurements have also demonstrated the need for more precise cross section data. In particular there are very few measurements of the np?d? cross section in the energy region of interest to BBN, none of which cover the important energy range of 50-400 keV. Measurements of this cross section are being undertaken at the WNR facility of the Los Alamos Neutron Science Center (LANSCE)