Abstract: A shield or screening device for radio-isotope producing generator including a moveable portion which can be moved relative to a stationary portion between a closed position to cover the generator and an open position to allow the generator to be inserted or withdrawn from the shielding device. The interaction of these two portions minimizes space required to use and shield the generator. Each portion is configured to effect relative rotative movement so that the moveable portion can be rotated concentrically within the circumference of the stationary portion. The generator can be inserted through the openings defined by the adjacent moveable and stationary portions in the open position. Once the generator is in place, the moveable portion is simply rotated to the closed position where the generator is substantially completely enclosed by the stationary and moveable portions of the shield.