R&D Program on sealing issues for in-service inspection and repair tools on ASTRID sodium prototype

The development of in-service inspection and repair tools for sodium cooled nuclear reactors is a challenging task. In present design, the tools regardless of their design and function are foreseen to be embedded inside a bell mounted on a remote handling device. Apart from the constraints inherent to the remote actuation and the docking of the system on the vessel structures, the high temperature sodium-tightness of the bell is a tedious issue to solve. This paper presents the R&D program conducted at CEA-Technetics sealing laboratory to address this matter. This program is divided along two axes, a characterization phase with radiation and sodium aging of several elastomer compounds, and the development of a full scale mock-up of a docking flange to qualify the sealing efficiency of different profiles. Advanced concepts of sealing systems and mechanical obturator for the inspection bell developed in the frame of this program are presented. (author)