Kinetic hydrogen isotope effects and flow compensation strategy of the ZrCo-based chemical beds in full-scale SDS demo-system.

• Kinetic hydrogen isotope of ZrCo-based beds are investigated on a full-scale SDS. • ZrCo-based beds present kinetic isotope effect scarcely during adsorption. • Compensation strategy is proposed to reduce H/D fluctuation during rapid delivery. ZrCo-based bed, commonly exploited to efficiently process large quantities of mixed hydrogen isotope gases, is one of crucial component in the storage and delivery system (SDS) of the tritium plant in fusion reactor. However, the hydrogen isotope effect on the desorption and adsorption processes of the ZrCo based assemblies has not yet clearly addressed, especially for a full-scale (100 g of Tritium) bed assembly. Herein, the kinetic hydrogen isotope effect of the full-scale ZrCo-based chemical beds, including ZrCo, Zr 0.8 Ti 0.2 Co, Zr 0.8 Hf 0.2 Co, with different hydrogen isotope ratios in SDS demo-system are investigated in detail. This work shows that the kinetic adsorption isotope effect of all ZrCo based beds are independent of pressure, temperature, and hydrogen isotope ratio. Conversely, the kinetic hydrogen isotope fluctuation is prominent during hydrogen desorption, where the proportion of protium is relatively high at the initial stage. After that, deuterium is easier to release. Finally, the protium gradually increases. The fluctuating degree is in the sequence of Zr 0.8 Ti 0.2 Co > ZrCo > Zr 0.8 Hf 0.2 Co for types of chemical beds, and 50%D + 50%H > 90%D + 10%H > 10%D + 90%H for isotope components. Based on experimental details, a flow compensation approach to ensure a stable ratio of hydrogen isotope gas is proposed. This work is of crucial significance for practical-scale SDS system operation, which is the prerequisite for the steady-state running of the fusion reactor. [ABSTRACT FROM AUTHOR]