TRIEX-II: an experimental facility for the characterization of the tritium extraction unit of the WCLL blanket of ITER and DEMO fusion reactors

Abstract

The experimental qualification of the Tritium Extraction Unit (TEU) from the LiPb eutectic alloy (15.7 at. % Li), the breeder material of the Water-Cooled Lithium-Lead (WCLL) breeding blanket concept, is one of the fundamental items for the demonstration of tritium balance sustainability for ITER and DEMO fusion reactors. Several technologies have been proposed as TEU, but the selection of the reference technology can be carried out only after the experimental measurement of the tritium extraction efficiency. For this purpose, a dedicated facility, called TRIEX-II, was designed and installed at ENEA Brasimone research centre, Italy. The facility is able to qualify Gas-Liquid Contactor (GLC), Permeator Against Vacuum (PAV) and Liquid-Vacuum Contactor (LVC) technologies at different temperatures, lithium-lead mass flow rates and hydrogen isotopes concentrations. In TRIEX-II, the hydrogen or deuterium, used to simulate tritium, are solubilised inside the LiPb with a dedicated saturator and are then extracted from the liquid metal in the GLC mock-up, which uses pure helium or a mixture constituted by helium and hydrogen as stripping gas and works in the temperature range between 300 and 500 °C.

Theoretical evaluation of the tritium extraction from liquid metal flows through a free surface and through a permeable membrane

“…However, the experimental validation of the technique using liquid metals is still pending. New PbLi facilities have been built for addressing this challenge in the near future [10][11][12].…”

Synthesis and Structural and Strength Properties of xLi2ZrO3-(1-x)MgO Ceramics—Materials for Blankets

“…The use of lithium ceramics based on titanates, silicates, or zirconates is potentially attractive because of the possibility of producing tritium as a result of nuclear reactions of lithium with neutrons. Moreover, most experts in this field agree that the use of lithium or lithium-containing ceramics will completely solve the problem of tritium fuel for thermonuclear energy, since lithium reserves will last for quite a long time [ 10 , 11 , 12 ]. The creation of blankets based on lithium ceramics must meet a number of requirements, the most significant of which are high mechanical strength and resistance to cracking and destruction under prolonged irradiation or temperature changes, excellent thermal conductivity, and increased resistance to thermal expansion (linear and volumetric) [ 13 , 14 , 15 , 16 , 17 , 18 ].…”