D R A F T - 16-Jan-2006

WBS 1.5 Vacuum Vessel 

Main Vessel

Procurement Package 1.5-1A
"Main Vessel and Blanket Manifolds"

ITER Cost 2001 for Sharing: 124.2 kIUA

Sharing: EU=80% , Korea=20%

Function, Scope of Supply:

The vacuum vessel, of toroidal shape, is inserted within the Toroidal field coils. The structural requirements are determined by the need to sustain the mechanical loads produced by the interaction of current, induced by magnetic flux variations, with the magnetic field.

The vacuum vessel
forms, as well, the first containment for the radioactive environment and it is shielded in order to reduce the streaming of high energy neutrons. The vacuum vessel is a Safety Classified Component and its design and manufacturing  has to respect nuclear grade structural code requirements

 

The Vacuum Vessel, in order to attain ultra-high vacuum cleanness is ‘baked’ at 230 C with forced circulation of hot pressurized water in its double shell structure. In normal mode of operation the vessel is under neutrons radiation and it is cooled by water circulation at 120 C.

The supply includes the cooling circuit manifold for the elements of the blanket installed inside the Vacuum Vessel cooled with pressurized water

Description, Technologies :

The vacuum vessel is a Toroidal (doughnut shaped) vessel produced by the revolution of a D- shape profile (12 m high and 6 m wide) around the vertical axis.

The general structure is a double-shell vessel consisting of an internal shell an external shell and a number of reinforcement elements connecting the two shells. The shells, in AISI 316L(N), have 60 mm thickness and are connected by radial reinforcement of 30 mm thickness fabrication technology.

The fabrication process assumes the forming of plates and their joining by means of various welding techniques including TIG (Tungsten Inert Gas) and EB (Electron Beam welding) and nuclear grade qualification and inspection of welds.

The vacuum tightness of the vessel at ultra-high vacuum levels has to be guaranteed for the full operative life (>35 years).Therefore welding process and inspection methods must include high vacuum treatments and tests.

The vacuum vessel is formed by 9 sectors of 40 angular degree each, that have to be independently fabricated and transported to the ITER Site. Each finished sector has a weight of about 450 tons. The final dimensional tolerances are in the millimetre range

The final assembly on site of the 9 sector shall utilise welding processes similar to the ones above and has to produce with a double shell, vacuum and water tight double enclosure with millimiter range tolerances.

Main EIDI Activities Codes

50500

BOILER METAL WORK / MANUFACTURING TECHNIQUES

50700

GENERAL MACHINING WORK / MANUFACTURING TECHNIQUES

50300

CASTING AND MOULDING / MANUFACTURING TECHNIQUES

50200

MACHINE TOOLS, WORKSHOP AND QUALITY CONTROL EQUIPMENT

50100

SUPPLY OF RAW MATERIALS