Tritium Extraction from Lithium-Lead Eutectic Alloy: Experimental Characterization of a Permeator against Vacuum Mock-Up at 450?

Tritium extraction is one of the key open issues toward the development of the WCLL BB (Water-Cooled Lithium-Lead Breeding Blanket) of EU DEMO reactors, and different technolo-gies have been proposed to address it. Among them, the Permeator Against Vacuum (PAV) has promising features, but it has never been tested in a relevant environment. This work presents the first experimental results ever obtained for a PAV mock-up. The experiments were carried out at ENEA Brasimone R.C. with the TRIEX-II facility on a mock-up characterized by a shell and tube configuration and using niobium as a membrane material. The experimental campaign was carried out with LiPb flowing at about 450 degrees C and 1.2 kg/s, while the hydrogen partial pressure was varied in the range 170-360 Pa. The characterization of the PAV performance was conducted by measuring the hydrogen partial pressure drop across the mock-up and the hydrogen permeated flux through a leak detector calibrated with an external hydrogen calibration cylinder. Moreover, the permeated flux was confirmed by a pressurization test performed measuring the pressure increase on the vacuum side of the PAV. The results constitute the first verification of the possibility to operate a PAV in flowing LiPb and to quantify its capabilities.