Using a 3D Fokker-Planck code we examine the Toroidal Field (TF) ripple induced transport of NBI generated deuterons for the purposes of Neutral Particle Analyzer (NPA) diagnostics. The neutral loss fluxes measured in recent JET ripple experiments are compared with modeling results. The observed reduction of deuterium fluxes in the case of enhanced ripples might be quantitatively explained by ripple-induced diffusion of trapped NBI deuterons.