A system and testing rig were designed and built to simulate the use of an eversion robot equipped with a radiation sensor to characterise an irradiated pipe prior to decommissioning. The magnets were used as dummy radiation sources which were detected by a hall effect sensor mounted in the interior of the robot. The robot successfully navigated a simple structure with sharp 45{\deg} and 90{\deg} swept bends as well as constrictions that were used to model partial blockages.