  The next generation of accelerators for Megawatt proton and heavy-ion beams
moves us into a completely new domain of extreme specific energies of up to 0.1
MJ/g (Megajoule/gram) and specific power up to 1 TW/g (Terawatt/gram) in beam
interactions with matter. This paper is focused on deleterious effects of
controlled and uncontrolled impacts of high-intensity beams on components of
beam-lines, target stations, beam absorbers, shielding and environment. Two new
experiments at Fermilab are taken as an example. The Long-Baseline Neutrino
Experiment (LBNE) will explore the interactions and transformations of the
world's highest-intensity neutrino beam by sending it from Fermilab more than
1,000 kilometers through the Earth's mantle to a large liquid argon detector.
The Mu2e experiment is devoted to studies of the conversion of a negative muon
to electron in the field of a nucleus without emission of neutrinos.
