PRELIMINARY INTERPRETATION OF THE LIBRETTO-2 EXPERIMENTAL RESULTS IN TERMS OF TRITIUM PERMEATION BARRIER EFFICIENCY

Within the framework of a European Community program aiming at the development of a water-cooled lithium-lead (Pb17Li) blanket concept for a demonstration fusion reactor [1,2], experimental works are devoted to the development of efficient tritium permeation barriers. These works include in-pile tests (LIBRETTO experiments) with closed steel capsules containing stagnant Pb17Li, intended to assess under irradiation the efficiency of these barriers. In this paper, a method for interpreting LIBRETTO data is presented, which relies on the use of a 2-dimensional finite element simulation model exploiting the analogy between tritium migration and heat conduction. Preliminary results obtained with this model are also discussed, which seem to indicate that, under conditions comparable with the experiment, the permeation barrier tested in LIBRETTO-2 would reduce tritium permeation by about two orders of magnitude.