Design and Integration of the WCLL Tritium Extraction and Removal System into the European DEMO Tokamak Reactor

Abstract

The latest progress in the design of the water-cooled lithium–lead (WCLL) tritium extraction and removal (TER) system for the European DEMO tokamak reactor is presented. The implementation and optimization of the conceptual design of the TER system are performed in order to manage the tritium concentration in the LiPb and ancillary systems, to control the LiPb chemistry, to remove accumulated corrosion and activated products (in particular, the helium generated in the BB), to store the LiPb, to empty the BB segments, to shield the equipment due to LiPb activation, and to accommodate possible overpressure of the LiPb. The LiPb volumes in the inboard (IB) and outboard (OB) modules of the BB are separately managed due to the different pressure drops and required mass flow rates in the different plasma operational phases. Therefore, the tritium extraction is managed by 6 LiPb loops: 4 loops for the OB segments and 2 loops for the IB segments. Each one is a closed loop with forced circulation of the liquid metal through the TER and the other ancillary systems. The design presents the new CAD drawings and the integration of the TEU into the tokamak building, designed on the basis of an experimental characterization carried out for the permeator against vacuum (PAV) and gas–liquid contactor (GLC) technologies, the two most promising technologies for tritium extraction from liquid metal.

Manufacturing of PAV-ONE, a Permeator against Vacuum Mock-Up with Niobium Membrane

“…The manufactured mock-up is the subject of a testing campaign in the TRIEX-II facility [10] at ENEA Brasimone Research Centre [11], which will characterize the performances of the PAV technology at relevant operative conditions and shed new light on the possibility to use it as a tritium extraction system in a fusion reactor. The experiments in flowing LiPb foresee ranges of temperature (350-450 • C) and hydrogen partial pressure (100-300 Pa) relevant for the current configuration of the WCLL TER [12].…”