The new capabilities included in the MCNPX 2.6 code to simulate the 3He(n,p) reaction for nuclear well logging applications was implemented in this work. The results obtained confirm that it is useful to predict the count values, as it allows obtaining results comparable with the literature. Besides, the new capabilities of the MCNPX 2.6 allow producing the triton and proton reaction products and the expected pulse height spectrum from a 3He detector in which the wall effect is significant. It makes possible studies of the behavior of these reaction products as a function of the 3He detector design.