29th Symposium on Fusion Technology (SOFT 2016)

P4.191 Absorption-Desorption Models for the Determination of Tranport Parameters of Hydrogen Isotopes in Eutectic PbLi

8 Sep 2016, 14:20

1h 40m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 191

Poster I. Materials Technology P4 Poster session

Speaker

Gorka Alberro (Nuclear Engineering and Fluid Mechanics)

Description

The importance of the hydrogen isotopes transport parameters of Sieverts’ constant and diffusivity in the eutectic lead lithium alloy is well known, as long as it is vital for the determination of tritium management strategies at liquid-metal breeding blanket systems [Helium Cooled Lithium Lead (HCLL), or Dual-Coolant Lead-lithium (DCLL)]. Tritium transport parameters as solubility and diffusivity will determine the magnitude and kinetics of the induced tritium flux in the breeding region from the blanket to the helium cooling loop in the reference breeding blanket systems. These parameters also have to be taken into account in the design of future tritium extraction systems of the breeding alloy or in the He coolant purification system. A theoretical model has been developed to describe the interaction between hydrogen isotopes and the eutectic PbLi alloy and to derive the corresponding experimental values of diffusivity and Sieverts’ constant. This model has been developed for the particular boundary conditions of the Absorption-Desorption facility working at UPV/EHU. Both experimental stages of gas absorption and gas desorption, separated by a thorough pumping-down stage, are entirely simulated in order to reduce the very wide band in the available experimental data (two orders of magnitude) obtained by different research groups using different experimental techniques. The goodness of the theoretical model has been proved by the accurate reproduction of the absorption and desorption experimental signals obtained in the facility with sample temperatures between 523 and 773 K and gas pressures between 1 and 10⁵5 Pa.