There is provided a process for recovering block shaped graphite fuel elements made of a graphite block with a parallel cooling channel and which block contains the fuel arranged in separate zones. The process is especially useful for such fuel elements in which the cooling channels and the fuel zones are distributed in a screenlike manner adjacent to each other and wherein these fuel elements are first comminuted mechanically and then are reconditioned by burning and wet chemical separation into fissile material and waste material. For the mechanical comminution of the graphite block conical pins (or mandrels) are simultaneously pressed into several cooling channels until the block is broken apart along the entire length of these cooling channels.