Design and fabrication of a Permeator Against Vacuum prototype for small scale testing at Lead-Lithium facility

Abstract

Tritium recovery is one of the major issues of a future DEMO reactor, in order to accomplish with the requirement of tritium self-sufficiency. The EUROfusion Programme has considered the permeation against vacuum (PAV) technique as baseline for those blankets which use PbLi as breeder. A conceptual design of a squared multi-channel PAV for its implementation in an experimental PbLi loop, under construction at CIEMAT, has been produced. Previous studies have shown the feasibility of using vanadium, tantalum or niobium as PAV membrane due to their good permeability and compatibility with PbLi. In order to save costs and time a preliminary α-Fe membrane was considered for the prototype, in spite of its low permeability. However, due to mechanical problems related to the use of this material, a change in the design was produced in order to afford the use of vanadium. Structural calculations are also presented and evaluated to develop the best way to implement the manufacturing process, paying special attention to the interface between the membranes and the main structure in order to avoid leakages. Other important aspects such as keeping an adequate vacuum level and its arrangement system have also been considered.