Fabrication des barres de controle pour le reacteur BR2 par la technique de cofilage

The control rods of the Belgian reactor BR2 are cadmium tubes clad inside and outside with aluminium. These tubes have been experimentally fabricated by co-extrusion. It has been found possible, in a single operation, to obtain the finished aluminium element with a slightly alloyed cadmium centre ; the thickness varies by a maximum of 8 %, and the end irregularities are very short. This method also gives a very close contact between the centre and the cladding and provides an extremely
rigid tube.