Evaluation of mock-ups before manufacture of a shield block prototype by powder HIP

Hot isostatic pressing (HIP) of powder is proposed as a possible process for manufacturing primary wall blanket modules for the International Thermonuclear Experimental Reactor (ITER). The method is cost-effective and offers very good design flexibility. It also provides required, uniform material properties, and the material is easy to check with ultrasonic techniques. Bodycote Powdermet conducted a development programme as a part of a NET (Next European Torus) contract to manufacture a shield block for the ITER primary wall module prototype. The aim was to test the influence of geometry of the tube gallery on the tolerances of tube positions after HIP of one-eighth scale (724×318×299 mm3) prototype mock-ups. It also intended to verify results obtained earlier on the influence of fabrication parameters. Five mock-ups were produced. Four HIP cycles were tested using two different designs of the cooling galleries. Non-destructive testing was used and measurements on sections of the mock-ups were performed. The location of tubes facing the first wall is most important. Investigation showed very small differences between the locations of those tubes in the five mock-ups. For these mock-ups, the tolerances between the surface and the tubes could be kept within ±2 mm.