Experimental determination of solubility values for hydrogen isotopes in eutectic Pb–Li

Abstract

Hydrogen isotopes solubility in eutectic lithium–lead alloys is really important for the design of breeding blanket components that use this breeding material. The determination of the magnitude and kinetics of the tritium flux from the blanket to the helium cooling loop, along with the design of future tritium extraction systems of the breeding alloy or the He coolant purification system, will be defined on basic transport parameters such as solubility.The unacceptable scattering of Sieverts’ constant values in the historical measurements given by different experimental techniques, suggests that this is a very important and unresolved issue. In this work, it has been experimentally evaluated, using absorption and desorption techniques. The different measurement campaigns have been carried out in the temperature range from 523 to 922K and in the pressure range from 1 to 105Pa.This paper describes the work carried out in the preparation of the facility, the theoretical model developed to process the different results obtained by means of absorption and desorption runs. Final results obtained during several campaigns of measurements are provided.The obtained values of hydrogen solubility through the different campaigns show a similar value for the Sieverts’ constant, and therefore, a very little value for the activation energy in the solution process. Results are compared and discussed. The proposed correlation for hydrogen Sieverts’ constant in Pb–Li from these tests is KS [molm−3Pa−1/2]=8.64×10−3exp(–0.9/RT), R in (kJK−1mol−1).