The ITER Vacuum Vessel Pressure Suppression System (VVPSS) is designed to protect the ITER Vacuum Vessel from an over-pressure situation in the Vaccum Vessel due to any incident/accident resulting in rise in pressure such as LOVA (Loss of Vaccum Event), ICE (Ingress of Coolant Event) etc.. It consists of a partially evacuated suppression tank that contains sufficient amount of water at room temperature to condense the steam resulting from the most adverse water leakage into the Vacuum Vessel chamber.
The design study of the VVPSS Tank was performed as a part of Preliminary Design Review taking into consideration the detailed load specification. The Tank was designed based on ASME Section VIII Div. 2 Design by Rules. CATIA was used to create a surface model of the VVPSS Tank & ANSYS Workbench was used in the stress analysis. Structural assessment of the VVPSS Tank was performed as per ASME Code 2010 Section VIII Div. 2 Part 5 Design by Analysis. VVPSS Tank was assessed against failure due to Plastic Collapse, Local Failure, Ratcheting, Buckling and Fatigue. The tank was found safe at 20 mm shell thickness based on the allowable design.

Keywords: VVPSS tank, Thickness, ANSYS, ITER, ASME.