The technological development concerning the 12-rod irradiation test element for the gas-cooled fast breeder reactor irradiation at the BR-2 reactor at Mol, Belgium concentrated on the element head, the sealing problems at the venting manifold, the flow guidance tube, the surface roughening technologies for the cladding, and the rod-spacer interaction. Assembly of a dummy element has shown that the fuel element technology developed can be handled with adequate reliability. For the electrically heated calibration element, a spacer with insulated pads was developed and manufactured full scale. Calibration of the element manufactured is completed.