The beam duct of the VLHC will be subjected to various sources of beam related power losses which, for cryogenic  and vacuum reasons, need to be intercepted  by an actively cooled beam screen. Starting from the ongoing design work for the LHC, the dominating effects like synchrotron radiation, beam induced electron multipacting  and image currents  are discussed. The optimised design of a beam screen must satisfy in addition stringent vacuum requirements.