[en] Thousands of drums of radioactive/hazardous/mixed waste are currently stored at DOE sites throughout US; they are stored in warehouse facilities on an interim basis, pending final disposition. Recent emphasis on anticipated decommissioning of facilities indicates that many more drums of waste will be generated, requiring additional storage. Federal and state regulations dictate that hazardous waste covered by RCRA be inspected periodically for container degradation and to verify inventories. All known DOE waste storage facilities are currently inspected manually. A system to perform robotic inspection of waste drums is under development by the SRTC Robotics Group of WSRC; it is called the Stored Waste Autonomous Mobile Inspector (SWAMI). The first version, SWAMI I, was developed by the Savannah River Technology Center (SRTC) as a proof of principle system for autonomous inspection of drums in a warehouse. SWAMI I was based on the Transitions Research Corporation (TRC) HelpMate mobile robot. TRC modified the Helpmate to navigate in aisles of drums. SRTC added subsystems to SWAMI I to determine its position in open areas, read bar code labels on the drums up to three levels high, capture images of the drums and perform a radiation survey of the floor in the aisles. The radiation survey was based on SRTC patented technology first implemented on the Semi-Intelligent Mobile Observing Navigator (SIMON). The radiation survey is not essential for the inspection of drums, but is an option that can increase the utility and effectiveness of SWAMI in warehouses with radioactive and/or mixed waste. All the sensors on SWAMI I were fixed on the vehicle. From the success of SWAMI I, a second version, SWAMI II, was developed; it will be evaluated at Fernald and tested with two other mobile robots. Intent is to transfer the technology developed for SWAMI I and II to industry so that it can supply additional units for purchase for drum inspection