An extensive development programme performed especially in Europe has enabled the production of very good Be/CuCrZr alloy joints by HIPping. The progress on the fabrication of Be/CuCrZr joints in Europe is described in Lorenzetto et a/.155,161,162 and Sherock et a/.163 The HIP joining temperatures ranged from 540 to 580 °C. Different interlayers such as Cr, Ti, and Cu were tested and reported. The selection of the joining conditions used for the fabri­cation of representative first-wall mock-ups was done on the basis of mechanical test results performed with guillotine shear test specimens. The best results were obtained with Ti and Cu interlayers at 580 °C, in which the shear strength exceeded the yield strength of the parent materials as creep of the CuCrZr part or rupture of the Beryllium part was observed. Per­formance achieved with representative first-wall mock-ups exceed the present ITER design require­ments, namely, 30 000 cycles at 0.5 MW m~ peak heat flux plus transient events up to 1.4 MW m — for about 1000 cycles (see Section 4.19.5.1.2).

A neutron irradiation programme is still in progress to complete the full characterization with irradiated mock-ups (see Section 4.19.5.2).

In the frame of the ITER Programme, in addition to Europe, the countries that in the past were inter­ested to supply the ITER first wall were China, Korea, the Russian Federation, and the United States. The underlying development work which has recently been performed in these countries to estab­lish the necessary fabrication capability is summar­ized elsewhere (see, e. g., Sherock et a/.,163 Nishi et a/.,164 Hong et a/.,165 Youchison et a/.,166 Lee eta/.,167 Park era/.,168 Liu,169 and Chen170).