L. Sedano

A Pfd-based 1D model for dynamic and transient tritium transfers between ITER HCLL TBM auxiliary systems

ITER fuel demands and tritium availability scenarios will determine the pathway to future fusion reactors. Because tritium is not a resource available from natural sources and its emission from the facility should be minimized, to keep the material balance in the entire plant and to control its inventory and safety is an essential issue toward the DEMO reactor.

Tritium recovery from Pb-17Li alloy using a 2D-SiCf/SiC composite permeator column®

Abstract The high gas leak rate through SiCf/SiC makes such ceramic composites candidate material for tritium extraction. The main issues for the viability of a SiCf–SiC/Pb–17Li extractor are identified. The potential advantages of the proposed extractor concept are demonstrated.

Numeric implementation of two-phase tritium transport models for natural helium nucleated bubbles in lead-lithium. Implications for HCLL breeding blanket channels

Tritium (T) self-sufficiency requirement is linked to high helium (He) production rates in a D-T fusion reactor breeding blanket (BB). In Liquid Metal (LM) BB concepts, large local He concentrations may result in bubble formation, which might have an enormous influence in the components performance. The present work states that such a possibility is not remote in a Helium Cooled Lithium Lead (HCLL) BB design. Bubbles could act as an effective T sink, reducing T partial pressure in the bulk LM and thus affecting T inventory control. Models for He nucleation, bubble growth and transport, along with T absorption and transport, have been implemented in the CFD code OpenFOAM®. Classical Nucleation Theory has been used for He nucleation. In the growth model, bubble growth is controlled by diffusion (it is assumed that bubbles are small enough); the mean radius approach has been implemented in order to save computational time. Tritium absorption is modelled using the Lewis-Whitman film theory. He and T concentration maps have been calculated for a HCLL single channel. Results show the effect of gas bubbles on T concentration. A pressure driven nucleation case have also been calculated. Work presented is a first step towards the quantification of the complex phenomena involved in He nucleation in LM and its effects on T inventory within a BB design.

Tritium transport finite element modeling tools for breeding blanket design

Permeation is a complex phenomenon. Today the unique tool ITER QA pedigree qualified is a one dimensional tool, TMAP7, not suitable for the complex geometries present in the Breeding Blanket concepts, where 2D/3D simulation capacities of the permeation phenomenon are a real need. In pursuit of this objective, a group of new operators describing some of the different phenomena which make up the permeation process have been implemented in a Cast3M-based code, profiting from the capacities of this finite elements tool for multidimensional calculation. These operators have been compared with the reference 1D code in 1D geometries in order to prove their performance, and finally adapted and tested in 2D geometries. Quality check is given together with ongoing developments and expectable future work.

THM evaluations of Li-based breeder percolation rates through SiCf-structures

Abstract A thermal-hydro-mechanical (THM) finite element model (FEM) is being developed and benchmarked in order to compute multi-phase/multi-species liquid metal (LM) flow rates through fiber materials coupled with the material thermal–mechanical (TM) behavior. The code advance large capabilities for the analysis of tritium/helium problems related to the design of fusion technology SiCf/LM systems. An application exercise is done concerning the evaluation of the percolation rates through a SiC-fibred in-contact membrane that represents an issue for the qualification of tritium dissolved in Pb–17Li recovery columns.