Presentation and Preliminary Test of APRIL: A New Facility for the Characterization of Antipermeation Coatings for Fission and Fusion Applications

Antipermeation and anticorrosion coatings are being developed to reduce tritium permeation from liquid metal [LiPb of the water-cooled lithium-lead breeding blanket and Pb for lead-cooled fast reactors (LFRs)] to primary heat transfer systems. The facility APRIL (Alumina-coating for tritium Permeation Reduction for Innovative LFR) was designed and installed at ENEA Brasimone R.C. to characterize the permeation reduction factor (PRF) of the candidate coatings in static conditions.

In the current configuration, APRIL is composed of three pipes, closed at one end, that simulate the heat exchangers of the ALFRED LFR. Two of the pipes are coated with 3 µm of alumina with pulsed laser deposition techniques, the reference method for a fission reactor. The third pipe is uncoated. During the tests, all the pipes are filled with pressurized steam at 100 bar and 480°C, the steam generator condition of the ALFRED LFR. The tests are made in the gas phase; indeed, the three pipes are installed in a chamber filled with helium with a known concentration of deuterium that simulates tritium. Deuterium permeates inside the pipes, allowing for the evaluation of the PRF by means of the ratio between the measured permeated flux in the uncoated pipe and in the coated ones. A first test with 0.5% of deuterium was carried out and the evaluated PRF was about 13.5.