That seems likely - my guess is you'll need sufficiently efficient energy to power electromagnetic shielding. Although an old Submarine-style nuclear fission re

That seems likely - my guess is you'll need sufficiently efficient energy to power electromagnetic shielding. Although an old Submarine-style nuclear fission reactor might be just fine for that as well, and you won't have to worry about just venting spent fuel rods into vacuum (in a nuclear pulse type spaceship that bit of radiation is going to be the least of your worries...).