Device for building up an edge zone of pure graphite pellets around the operating pebble bed of a high temperature reactor

The device makes it possible to achieve an even design of the edge zone with a small number of supply pipes, without adverse effect on the flow of pellet operating elements into the active core. In order to build up the edge zone, an annular separation reaching to the surface of the pebble bed is fitted to the lower edge of the ceiling reflector, so that an annular gap is formed between the solid reflector jacket and the pebble bed separation, in which the graphite elements of the edge zone are placed and which is continued to the ceiling reflector. The central surface of the edge zone lies above the central surface of the operating pebble bed, preferably inside the part of the annular gap situated in the ceiling reflector. (orig./HP)