RAMI analysis of the ITER LFS CTS system

This paper describes an initial RAMI analysis for the ITER Low Field Side Collective Thomson Scattering system (LFS CTS) based on its preliminary architecture at system design level. The benefits and challenges involved in this analysis since an early phase of the design are discussed together with the methodology pursued.

The Functional Analysis, developed both at system and sub-system level, are the major inputs for the RAMI analysis. A systematic approach has been used, and significant design assumptions have been made due to the lack of knowledge and definition inherent to preliminary design stages. This study includes the Failure Mode, Effects and Criticality Analysis and the Reliability Block Diagram of the system.

The results obtained for the system Availability and Reliability are presented and discussed, and criticality charts are developed to highlight the risk levels of the failure modes, regarding to their likelihood and effects on the Availability of the ITER machine. Mitigation actions are proposed to reduce these risk levels in case of impact on the ITER operation.