Remote handling validation of the OPM-FDS connecting system for the IFMIF-DONES target assembly

• Validation of the OPM-FDS connecting system of IFMIF-DONES Target Assembly. • Remarkable performance of the OPM system in driving the bellow, achieving correct engagement and disengagement of the beam lines. However, the flexible shaft requires to be validated when irradiated to assess for actual suitability in operative conditions. • Satisfactory performances of the FDS when using the INCONEL 718 gasket, while with the AISI 304 L one the FDS was not able to satisfy the leak rate requirements. A deep characterization of the load curve of the FDS is required to gain more knowledge on the behavior of the torque transmitted. • Safety related systems require improvements due to inability to operate when in nominal conditions even at relatively low torque used in tightening the FDS. The qualification process of the materials for future DEMO fusion reactors plays a pivotal role towards its realization. In this light, the International Fusion Materials Irradiation Facility-DEMO Oriented Neutron Source (IFMIF-DONES) has achieved the final design stage and is currently under construction in Granada (Spain). IFMIF-DONES aims to reproduce the irradiation conditions foreseen on the first wall of DEMO by using deuteron-lithium stripping reactions induced by a D+ beam accelerated through a superconducting LINAC. These reactions occur in a Target Assembly (TA) within a closed cavity (Test Cell) housing the test modules. Due to the strong neutron activation, a Remote Handling System (RHS) is required to perform the maintenance operations in the Test Cell. Therefore, suitably custom-designed components necessary due to the conditions of IFMIF-DONES, must be validated from the RH point of view. In particular, the system responsible for connecting the TA with the accelerator beamline plays a key role. This system includes a compression element made of an extensible bellow actuated by a One-Point-Mechanism (OPM) and a circular chain acting as a Fast Detachment System (FDS), which secures the connection by applying the required tightening force on the sealing gasket. The main objective of this work is then to test and validate the OPM-FDS design with focus on the RH suitability. Therefore, to demonstrate the concept validity and qualify the system, the University of Granada made a prototype of the OPM-FDS connection in collaboration with ARQUIMEA® and delivered it to the ENEA Brasimone Center for experimental validation. The outcomes of the validation activity conducted in this work confirmed that the OPM-FDS design is suitable for Remote Handling and can perform several connections and disconnections. The rescue system, which detaches the FDS in case of failure, has also been tested successfully. The experimental campaign also showed some potential improvements in the design of the connecting system for further implementation.