RAMI analyses of the IFMIF accelerator facility and first availability allocation between systems

Abstract

An analysis in terms of Reliability, Availability, Maintainability and Inspectability (RAMI) has been done for each system (Injector, MEBT, SRF Linac, RF system⿦) of the deuteron accelerators of the International Fusion Materials Irradiation Facility (IFMIF). The goal of these analyses is to estimate the availability of the accelerator facility based on the current design in order to compare it with the high IFMIF availability requirements. A first availability allocation between accelerator systems was performed to quantify the improvement demanded in terms of RAMI to achieve such requirements. These studies highlight the critical parts and parameters that most likely can have an impact on downtime.Individual fault tree analysis was done for each system of the accelerator with the software RiskSpectrum® PSA Professional. With such model, a deep analysis was done and therefore major unavailability contributors for each system were presented. Statistical analyses were developed to evaluate time dependency, parameters and events importance, sensitivities and uncertainties. Results gave indications for possible improvements, whenever feasible, for each accelerator system.These studies have been performed in collaboration between system designers and RAMI experts enabling the creation of RAMI models that reflect the current accelerator design. The parallel activity on the design and construction of the Linear IFMIF Prototype Accelerator (LIPAc) provides detailed design information and allows the finding of the improvements that the final accelerator could have. Because of the R&D character of the LIPAc, design improvements based on the results of the RAMI analysis could be the major differences between LIPAc and the IFMIF accelerator design.