RAMI analysis of DONES Lithium systems updated to the last design modifications

IFMIF-DONES project is aimed at building a neutron source facility for fusion materials development and qualification. This facility will provide a database of materials exposed to similar irradiation conditions as in DEMO. Neutrons are obtained by means of a deuteron beam impacting onto a liquid lithium film target provided by the Lithium System (LS). An important aspect of the project design activities is to assess the system reliability at all phases of the facility life-cycle to support a reliability growth during the ongoing design phase and to monitor the compliance with the stated availability goals. Following RAMI methodology, first a Failure Mode Effect Analysis (FMEA) is done in order to point out all the relevant unavailability conditions in the Lithium Systems (e.g. main loop and related heat removal systems, impurity control system, target system, etc.). Then, RBDs (Reliability Block Diagram) are derived from FMEA by implementing a reliability-wise representation of system component behavior and simulate the system performance under due operating conditions. Finally, a Phase Diagram (PD) is defined to have into account all the different states of the LS (e.g. normal opeation, corective maintenance (CM) and preventive maintenance (PM)) during two years of operation, a cycle that is repeating for 20 years of operation. The current design detail level and functioning logic is taken into account also considering the foreseen Local Instrumentation & Control System. The compliance with the availability target of 94% attributed to the Lithium System during its operation time is verified.