Methodology for dimensional variation analysis of ITER integrated systems

Abstract

The ITER machine consists of a large number of complex systems highly integrated, with critical functional requirements and reduced design clearances to minimize the impact in cost and performances. Tolerances and assembly accuracies in critical areas could have a serious impact in the final performances, compromising the machine assembly and plasma operation. The management of tolerances allocated to part manufacture and assembly processes, as well as the control of potential deviations and early mitigation of non-compliances with the technical requirements, is a critical activity on the project life cycle.A 3D tolerance simulation analysis of ITER Tokamak machine has been developed based on 3DCS dedicated software. This integrated dimensional variation model is representative of Tokamak manufacturing functional tolerances and assembly processes, predicting accurate values for the amount of variation on critical areas.This paper describes the detailed methodology to implement and update the Tokamak Dimensional Variation Model. The model is managed at system level. The methodology phases are illustrated by its application to the Vacuum Vessel (VV), considering the status of maturity of VV dimensional variation model.The following topics are described in this paper:•Model description and constraints.•Model implementation workflow.•Management of input and output data.•Statistical analysis and risk assessment.The management of the integration studies based on the Tokamak Dimensional Variation Model is also reported.ITER is a Nuclear Facility INB-174 (Installation Nuclear de Base no. 174). This paper describes a Protection Important Activity (PIA) for safety.