Evaluation of tritium leakage rate into seawater in fusion DEMO cooling water system

Abstract

The primary cooling water systems (CWS) of the blanket and the divertor is anticipated to have several amount of tritium because of permeation from the core plasma. In this research, the required performance of DEMO tritium removal facility to control the primary tritium concentration has been calculated and it is shown that existing devices can be applied to DEMO. The primary tritium is also anticipated to permeate the pipes to the downstream CWS and turbine system. Finally, tritium in turbine system permeates a condenser pipes and is leaked into seawater. The evaluation of tritium leakage rate into seawater has been done. Because of tritium transport model from water to water is not well known, gas to gas calculation model is used. The results show that a heat exchanger decreases the tritium permeation rate by 1 order of magnitude, and H2 addition to the upstream cooling water also decreases the tritium permeation rate by 3 orders of magnitude.