This paper presents a new robotic device whose main objective is to increase the flexibility of current systems used to carry out inspection and manipulation of spent nuclear fuel inside dry storage unit cells. Instead of using a rigid kinematic chain, the proposed device is based on the idea of a capsule that can be deployed inside a cell with the appropriate tool by means of a conventional crane and cable. The device is equipped with extendable actuators that immobilize the whole system inside the cell by pushing against the walls. This provides a stable platform for those tools that have to execute precision tasks. The system also comprises an industrial tool changer that allows the deployment of the required tool for each specific task. A first prototype of the device and a tool to retrieve spent nuclear fuel were built, and the results of the initial experiments are reported at the end of this paper.