Failure mode and reliability analysis is particularly important for robot manipulators to be deployed in remote environments, where inspection and repair are diffcult, and reliability is of prime importance. This is particularly true for manipulators involved in hazardous waste management operations, where failure could be both expensive and highly dangerous. In this paper, we describe a Fault Tree Analysis and detailing of the major failure modes of a robot manipulator-based system for tank waste retrieval. The advantages and limitations of this type of analysis for hazardous waste robotics are detailed and discussed.