  The determination of the injection composition of cosmic ray nuclei within
astrophysical sources requires sufficiently accurate descriptions of the source
physics and the propagation - apart from controlling astrophysical
uncertainties. We therefore study the implications of nuclear data and models
for cosmic ray astrophysics, which involves the photo-disintegration of nuclei
up to iron in astrophysical environments. We demonstrate that the impact of
nuclear model uncertainties is potentially larger in environments with
non-thermal radiation fields than in the cosmic microwave background. We also
study the impact of nuclear models on the nuclear cascade in a gamma-ray burst
radiation field, simulated at a level of complexity comparable to the most
precise cosmic ray propagation code. We conclude with an isotope chart
describing which information is in principle necessary to describe nuclear
interactions in cosmic ray sources and propagation.
