Investigating the best path forward

In March this year we identified four outstanding issues with the design of the ITER vacuum vessel and its in-vessel components. In short, these issues related to the nuclear shielding of the present vessel, the forces on the blankets during abnormal events and the integration of the ELM coils into the present design which has been a challenge from the beginning. In addition, the manufacturability of the vessel including repair and cost issues was brought to our attention by industries both in Korea and Europe.

Triggered by these issues, we allowed ourselves three months to launch a detailed study of possible technical solutions for the baseline design as well as a potentially attractive alternative design as a backup option. This decision was supported by all Domestic Agencies.

The results of this effort were presented and discussed in a comprehensive design review here in Cadarache last week, 7-10 July. The review was conducted by the former Deputy Director of the Princeton Plasma Physics Laboratory, Rich Hawryluk, with participation from engineers and scientists from all around the world. The facts and figures that had been prepared for the studies were explored "with creativity and ingenuity and substantial progress in a short period of time," as the review committee stated, allowing a comparative assessment of both options.

The committee concluded that the reference design was more mature at this time and with some necessary modifications much closer to meeting the technical requirements of ITER. It recommended to go ahead with the reference design with the understanding that the design and integration of the in-vessel coils are satisfactorily resolved and a confirmatory analysis of the nuclear heat load is completed.

I very much appreciate the recommendation made by the review committee and I am happy to report that we feel very much encouraged by these comments.

Following this week's meeting of the ITER Senior Management, we decided to proceed with the reference design. We will implement the necessary technical modifications over the coming months, while concurrently the preparation for the tendering process is moving ahead satisfactorily.

I want take this opportunity to express my gratitude to everybody who contributed to this exercise. I very much appreciate the efforts of our colleagues both here in Cadarache and the Member Parties. "The vacuum vessel is the key," as my Deputy Director-General Gary Johnson pointed out during the review. And no doubt, it is certainly of most important component in ITER, interfacing with many other components of the machine. That is why this review process was of enormous significance to the project. I believe that through this process we have demonstrated our capability to manange such emerging issues in a timely and reliable manner.