A first primary wall small scale mock up with beryllium as the armor material was manufactured by hot isostatic pressing (HIPing) by CEA and tested at the electron beam test facility JUDITH. The mock up consisted of a 9.4 mm thick beryllium armor joint onto a 20 mm thick dispersion strengthened copper (DS-Cu) alloy plate. Type 316L Stainless Steel tubes, 10/12 mm in diameter were embedded in the DS-Cu, which was subsequently joined onto a 30 mm thick 316LN stainless steel plate. The mock up was tested under a surface heat flux of 2.5 MW m −2 for 100 preparatory cycles and 900 cycles of 30 s heating and 30 s cooling time. At the end of the 1000 cycles, the surface and the Be/DS-Cu joint of the mock up did not show any damage due to the fatigue test.