PAV-2: a new mock-up to investigate niobium membrane-PAV performances optimization in PbLi systems

Permeator Against Vacuum was confirmed in 2023 as the reference technology for the tritium extraction and removal (TER) system of the Water-Cooled Lithium-Lead Breeding Blanket (WCLL BB) due to its overall better performances and higher Technology Readiness Level. The manufacturing and the first characterization of a PAV with a niobium membrane in a shell and tube configuration with U-tubes (PAV-ONE mock-up) was recently performed at ENEA Brasimone R.C., demonstrating that this technology can be satisfactorily employed in PbLi. This paper will present the design of a new PAV test section with niobium membrane to be installed in the TRIEX-II facility. The objective of the new mock-up is to investigate the correlation between the extraction flux and different parameters to optimize the future design of the technology. In particular, PAV-two will allow to deeply examine the influence of turbulence, vacuum pressure, and surface conditions on the hydrogen transport in the system and, therefore, on the performances of the technology. The simple and flexible design of PAV-two will enable the discrimination of each parameter’s impact on the extracted flux in a repeatable and reliable manner.