Vacuum vessel
Last phase for Europe's sector #5
1 Mar 2021
The first European vacuum vessel sector is entering an important and critical phase: the assembly and welding of four segments into the D-shaped sector. Under the supervision of the European Domestic Agency, the AMW consortium (Ansaldo Nucleare, Mangiarotti, Walter Tosto), supported by an extended network of sub-suppliers located in France, Germany and Spain, is ready for the challenge.
Final machining is underway on one segment for sector #5 at Walter Tosto (Chieti, Italy). Four segments (inboard, upper, equatorial and lower) will be assembled into the final D-shaped sector.
Four poloidal segments are assembled into the final 40-degree vacuum vessel sector.
Vacuum vessel sector #5 will be the first of five sectors delivered to ITER by the European Domestic Agency. It has been more than nine years in the making, leading the pack as the European AMW consortium carried out extensive R&D and prototyping, learned to organize manufacturing tasks among the consortium members, and pioneered advanced welding and inspection techniques. The double-wall structure of the vacuum vessel, complex geometry, French nuclear safety regulations, and new rules and restrictions imposed by the Covid-19 pandemic are some of the challenges highlighted by engineers in a recent report by Fusion for Energy, the European Domestic Agency.
The four segments that make up Sector #5 are in the last stages of completion; only some final machining and non-destructive evaluation tests remain before the four segments will be positioned on a vast assembly platform and welded together. Four other sectors are in various stages of fabrication in Europe; Korea is also supplying four sectors. See more detail about European manufacturing in the gallery below.
See the original story on the Fusion for Energy website.
At Walter Tosto a number of assemblies are underway, including segment 2 (PS2) for vacuum vessel sector #4 (centre). European Domestic Agency project managers make sure information circulates so that good practices and lessons learned can be shared among manufacturing sites.
Work is progressing on segment 3 (PS3, yellow in the diagram above) for sector #5 at Walter Tosto (Chieti, Italy). Every weld is verified through non-destructive examination.
When all in-wall components are in place, an outer shell will be fitted and welded. Each vacuum vessel sector has more than 1 kilometre of welds. (Sector #3, poloidal segment 2 (PS2) at Belleli.)
The upper segments (in dark blue, above) are called PS2 segments. This one, in fabrication at Belleli (Mantova, Italy), is destined for vacuum vessel sector #3. Note the complexity of the curvature, the opening reserved for the upper port, and the channels between the ribs that will be filled with in-wall shielding blocks for neutron shielding.