Three-dimensional neutronics calculations have been performed for the ITER divertor cassette design options to determine the nuclear parameters in the cassettes and assess the impact of streaming on vacuum vessel and toroidal field (TF) coil damage. The local nuclear parameters in the components of the reference cassette design are similar or lower than those in the cassette design option with wings. The total nuclear heating in the 60 divertor cassettes is 102 MW for both designs. Helium production levels in the vacuum vessel in the divertor region allow for rewelding. The TF coils are well protected from radiation streaming into the divertor ports.