Trace tritium recovery from the residue of liquid Li17Pb83 alloy

Abstract

The liquid Li17Pb83 alloy is a prominent breeder material for use in a fusion reactor. In the design of an effective tritium extraction system for the liquid lithium lead bubbler of the test blanket module of such a reactor, finding ways to strictly limit the losses of tritium and to minimize radioactive risks is very important. For this purpose, the isotope exchange process has been investigated as a means of trace tritium recovery from a model of the residue from Li17Pb83 alloy. The results indicate that the isotope exchange process is an effective means of tritium recovery from the residue of Li17Pb83 alloy, and the optimum composition of the exchange carrier gas is He + 0.1% D2. The exchange temperature and number of exchange steps are the main factors influencing the efficiency of tritium recovery from the residue. Trace tritium recovery efficiency increases with increasing exchange temperature and number of times of exchange. Tritium recovery efficiency can approach 80% when the residue is treated six times at 823 K. A gas-liquid two-phase contact model to describe the proceeding of tritium release from the liquid Li17Pb83 alloy has been derived on the basis of this experiment.