nebbione said:
Can a nuclear engineer consider himself even a nuclear physicist or an expert in nuclear physics ?
Generally, no. Other than neutron physics, most of what a nuclear engineer studies or applies is based on classical (non-relativistic and non-QM) physics, e.g., heat transfer, structural mechanics, fluid mechanics and materials science. A nuclear engineer may have some experience in electrical engineering, e.g., circuits and analysis, magnetic fields, and electromechanics. These are also primarily based on concepts in classical physics.
To become proficient in nuclear physics, one would need a physics degree with specialization in nuclear physics, including SR, QM and QCD.
Most nuclear engineers have some introductory course work in nuclear and atomic physics. This is related to cross-sections of neutron and particle interactions, and radiation effects on matierals.
Are there some works in the aerospace industry for a nuclear engineer or an energy engineer ?
Yes. Knowledge of heat transfer, structural mechanics, fluid mechanics and materials science are transferable to a variety of engineering fields.
Some nuclear engineers may specialize in nuclear propulsion.