Progress on the design of a brazing connector for DEMO in-vessel components

Abstract

The main unavailability sources in a fusion power plant will be caused by the replacement of large in-vessel components, as well as by components failure and short duration maintenance tasks and inspection processes. The development and validation of remotely operable leak-free pipe connectors for helium, water and liquid metal is a key issue for faster and more reliable replacement of in-vessel components. In this work, some advances in the design of a connector by brazing for DEMO blanket pipes are presented. A new clamping concept to stiffen the connector is proposed, although different previous works suggest the mechanical strength of the brazed joint could be enough and the clamp may not be necessary. A characterization of the mechanical behavior of the brazed joint, a CFD approach for modeling the capillary flow of the BAu-4 filler metal during the brazing process and a preliminary assessment on the issue of tritium permeation are included.