During the Basic Performance Phase of ITER operation, a modularized shielding blanket integrated with the first wall (FW) will be installed. To examine and develop the manufacturing method of the shielding blanket, a medium scale mock-up was fabricated incorporating its major structural features.

In the present ITER shielding blanket design, the FW has cooling channels (SS316LN tubes) embedded in Cu-alloy heat sink bonded to the shielding block(SS316LN). The shield block also has its own cooling channels appropriately arranged to remove volumetric nuclear heating generated in the block. The integrated FW/shielding blanket(block), especially the FW surface, has poloidal and toroidal curvature to go along with the plasma magnetic surface. The width of the blanket module, accordingly the space between FW and shield block cooling channels, varies in poloidal direction. For fabricating the shielding blanket module, the use of Hot Isostatic Pressing(HIP) technique has been proposed as a promising joining method, especially for the FW, to avoid fusion welds which might be seriously affected by severe neutron irradiation.

The medium scale mock-up is the size of approximately 500mm wide, 800mm high and 350mm thick was fabricated incorporating above main blanket features except for the toroidal curvature. For the fabrication of the FW,SS(SS316L) circular tubes of 10mm in inner diameter and 1mm in thickness were sandwiched by two semi-circular grooved DSCu plates. As for the shield block, a forged SS(SS316L) block was machined by drilling from both sides for the cooling channels. Then the shield block was poloidally bent by 10000 ton class press at room temperature. Metal(aluminum alloy) rods were inserted into each drilling cooling channels to avoid their excessive deformation during the bending. After the bending, the metal rods were melted out. The DSCu plates, SS tubes and SS shield block were assembled together and bonded by single step HIP with conditions of 1050 $B!n!$ (J150MPa, and hold time of two hour. After the HIP bonding , metallographic observations of HIPed interfaces was performed using the parts including three FW channels and five shield block cooling channels, which had been prepared for this observation and cut from the mock-up end. There were no harmful voids observed at the bonded interfaces, and deformation of the shield block cooling channels were also negligibly small.

Consequently, the feasibility of the simultaneous bonding of DSCu-to-DSCu, DSCu-to-SS and SS-to-SS joins by single step HIP and the soundness of the joins were confirmed. Also engineering data on the fabrication method and procedure of the integrated FW/shield blanket was obtained. Thermo-mechanical testing of the fabricated medium scale mock-up will be performed at JAERI soon.