A. Terasawa

ITER vacuum vessel design and construction

Abstract According to recent design review results, the original reference vacuum vessel (VV) design was selected with a number of modifications including 3D shaping of the outboard inner shell. The VV load conditions were updated based on reviews of the plasma disruption and vertical displacement event (VDE) database. The lower port gussets have been reinforced based on structural analysis results, including non-linear buckling. Design of in-vessel coils for the mitigation of edge localized modes (ELM) and plasma vertical stabilization (VS) has progressed. Design of the in-wall-shielding (IWS) has progressed in details. The detailed layout of ferritic steel plates and borated steel plates is optimized based on the toroidal field ripple analysis. The procurement arrangements (PAs) for the VV including ports and IWS have been prepared or signed. Final design reviews were carried out to check readiness for the PA signature. The procedure for licensing the ITER VV according to the French Order on Nuclear Pressure Equipment (ESPN) has started and conformity assessment is being performed by an Agreed Notified Body (ANB). A VV design description document, VV load specification document, hazard and stress analysis reports and particular material appraisal were submitted according to the guideline and RCC-MR requirements.

Design and manufacture of the ITER Vacuum Vessel

The main functions of the ITER Vacuum Vessel (VV) are to provide the necessary vacuum for plasma operation, act as first nuclear confinement barrier and remove nuclear heating. The design of the VV has been reviewed in the past two years due to more advanced analyses, design modifications required by the interfacing components and R&D. Following the signature of four Procurement Arrangement (PAs), the manufacturing design of the VV sectors, ports and In-Wall Shielding (IWS) is being finalized and the fabrication of the VV sectors has been started in 2012.

Fabrication Preparation of ITER Vacuum Vessel—Material Considerations, Regulatory Requirements, and Fabrication Plans

Abstract SS 316 L(N)-IG (ITER grade) has been selected as the main structural material for the ITER vacuum vessel (VV), considering its high mechanical strength at operating temperatures, water chemistry properties, excellent fabrication characteristics, and low cost relative to other candidates. The ITER VV is a class-2 box structure as defined in RCC-MR, 2007 edition, which was selected as the code for the design and construction. This paper describes materials, applied code and regulatory requirements, baseline fabrication procedures, and assembly on the site.

Design Progress of the ITER In-Wall Shielding

Abstract The space between the double walls of ITER Vacuum Vessel is filled with pre-assembled or modular shield blocks called “in-wall shielding”. It has two main functions; one is to provide an effective neutron shielding and the other to reduce the toroidal field ripple in the outboard region. The in-wall shielding is designed to minimize electromagnetic forces acting on the shield blocks. The electromagnetic forces have been calculated with the latest disruption scenarios. Magnetization forces have also been calculated for ferromagnetic inserts. Structural integrity has been validated by structural analyses.