N.I. Her

CONSTRUCTION, ASSEMBLY AND COMMISSIONING OF KSTAR MAIN STRUCTURES

The KSTAR device succeeded in first plasma generation on June of 2008 through comprehensive system test and commissioning. Among various kinds of the key factors that decisively affected the project, success in the construction and assembly of the major tokamak structure was most important one. Every engineering aspects of each structure were finally confirmed in the integrated commissioning period, and there were no severe troubles and failures prevented the KSTAR device from operating during the commissioning and the first plasma experiments. As a result, all of the experiences and technologies achieved through the KSTAR construction process are expected to be important fundamentals for future construction projects of superconducting fusion devices. This paper summarizes key engineering features of the major structures and of the machine assembly.

Structural analysis of the ITER Thermal Shield

The structural rigidity of the ITER Thermal Shield (TS) has been verified by structural analysis. In this paper, the analysis process, methodology and demonstration of the structural integrity for the TS are described. The analysis are performed for the TS global model and detailed model such as supports and joints. TS joints in the shell model are modeled using orthogonal material properties, because using sufficiently refined joint models in the global model of TS sector is almost impossible and highly time-consuming. Joint orthogonal properties are calculated based on the periodical composite cell theory. To verify the structural rigidity for the TS, plastic collapse, buckling, ratcheting and fatigue are assessed in accordance with ASME VIII, Div. 2.

The construction of ITER, viewed from lessons learned from the KSTAR project

The construction of ITER is an extremely important project, not only within the fusion society but also for mankind: By solving critical energy and environmental problems, another major step in human history will be taken. Design, construction, and assembly of an ultra large scale machine such as ITER require thoroughly well defined plans, strategies, and predictions of potential problems and solutions. It is believed that preceding devices and projects may provide useful references for the several important considerations noted above. The KSTAR (Korea Superconducting Tokamak Advanced Research), a representative superconducting tokamak, has the most similar characteristics to the design concept of the ITER. Therefore, the lessons learned from KSTAR can be categorized according to the following engineering aspects: 1) policies to prioritize decisions, 2) catch-up plans for delayed schedules, 3) strategies in site assembly, 4) troubleshooting, 5) standard indexes or guides for tests and acceptance of individual systems and of site assemblies, and 6) interfaces that can be easily omitted in view of the system integration. This paper will summarize the lessons we have learned from the KSTAR project, focusing on engineering related points that can be considered to suggest guidelines for the ITER construction.