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Abstract: The structure and fabrication methods of the ITER vacuum vessel (VV) have been investigated and defined by the ITER International Team (IT). However, some of the current technical specifications are difficult to be achieved from the manufacturing point of view. To solve such an issue, this paper proposes an alternative specification of the VV to the IT''s design. A series of the fabrication and assembly procedures for the mock-up are presented, together with candidates of welding configurations. Finally, the paper summarizes the results of mock-up fabrication, such as non-destructive examination of weld lines, obtained welding deformation and issues revealed from the fabrication experience. Based on the results, it is suggested that several issues such as clarification of conditions of repair welding, demonstration of welding distortion control and detectability/localization of internal defects should be solved before manufacturing the ITER VV. [Copyright &y& Elsevier]

Abstract: The design of in-vessel transporter (IVT) including vehicle manipulator has been updated according to the design changes such as blanket segmentation and structure, taking account of the interface between modules and vehicle manipulator. In particular, the updated design of the vehicle manipulator and rail has been carried out because of collision avoidance between modules and vehicle manipulator. According to the updated design, the vehicle manipulator has been reduced by about 30% in weight, compared with the reference design. In parallel with design activities, the R&D to clarify the specifications of the IVT design in detail is also performed, i.e., simulation system to provide the visual information during maintenance, dry lubricant to prevent the lubricant oil from spreading in the vacuum vessel (VV). The rail connection and cable handling in the transfer cask, which are critical issues for IVT system, are under preparation of the demonstration tests to finalize the design of the IVT system. Connection of the rail joint and cable handling test facilities are planned and under fabrication now. These test facility will be installed by the end of March 2008, and the performance tests will be carried out from April 2008. [Copyright &y& Elsevier]

Abstract: Recent progress of the ITER vacuum vessel (VV) design is presented. As the ITER construction phase approaches, the VV design has been improved and developed in more detail with the focus on better performance, improved manufacture and reduced cost. Based on the achievements of manufacturing studies being performed in cooperation with the ITER participant teams (PTs), design improvement of the typical VV sector (#1, see the legend to figure 1 in this article) has been nearly finalized. Design improvement of other sectors is in progress—in particular, of the VV sectors #2 and #3 which interface with tangential ports for the neutral beam (NB) injection. For all sectors, the concept for the in-wall shielding has progressed and developed in more detail. The design progress of the VV sectors has been accompanied by the progress of the port structures. Structural analyses have been performed to validate all design improvements. [Copyright &y& Elsevier]

Abstract: The dynamic behavior of the ITER tokamak assembly has been investigated, using a 1/5.8-scale model. In the static load test, the observed deformations and stresses were confirmed to be linearly proportional to the applied loads. In the vibration test, the first and third eigen-modes corresponded to horizontal vibration modes, with natural frequencies of about 29 and 81Hz, respectively. The global-twisting and oval modes were found to be in the second and forth modes, with frequencies of about 60 and 86Hz, respectively. A comparison of experimental and analytical results showed that the deflections and the induced stresses in the analysis were approximately half of those found in the experiment. Natural frequencies have also been compared. The frequency in the first mode was almost the same for both the experiment and the analysis. However, in higher vibration modes, the natural frequencies in the experiment were found to be smaller than those in the analysis. To further examine the dynamic behavior of the coil structure, a vibration test of the entire sub-scale model is planned using the vibration stage rather than the shaker. [Copyright &y& Elsevier]

This paper presents an overview of ITER-supporting materials R&D activities and major achievements in Japan during the period from the Co-ordinated Technical Activities to date. In view of the completed engineering design of ITER during the Engineering Design Activities period, R&D efforts since then have been focused on: those for reduction of component fabrication cost; those in support of domestic preparations of a structural technical code for construction; and those necessary for operation, and been extended to component-level testing rather than pure material testing. They cover materials R&D for in-vessel components, vacuum vessel, cryogenic steels of superconducting magnets and diagnostics components. Major achievements in each R&D area are highlighted and their impact or implication to the design, construction and operation of ITER is presented. [Copyright &y& Elsevier]