Interestingly, that may actually make the collider-produced neutrinos less dangerous than those from a supernova. I'm not sure how it translates to other types of radiation, but at least for neutron radiation (e.g. cosmic rays) the amount of energy one would absorb peaks and then falls off at higher energies. Not harmless though, just slightly less dangerous.
Neutrino cross sections increase with energy, so these are much more dangerous than from a supernova. Note that when they do interact, much or all of the energy of the neutrino manifests in a form that can then interact further, so the more energetic neutrino also creates more secondary radiation when it does interact.
