A summary of tritium behavior in nuclear power plants

Tritium (H-3) is one of the most notable radioactive nuclides in nuclear facilities due to its typical production and diffusion mechanism. Its influence on the environmental safety and public dose attracts more and more attention from various research fields worldwide. This paper investigates the production mechanisms of tritium in different types of nuclear facilities. The sources and proportions of tritium in light water reactors (LWRs), heavy water reactors (HWRs), high temperature gas-cooled reactors (HTGRs), and liquid metal fast breeder reactors (LMFBRs) are investigated and comprehensively compared. The discharge standards of the liquid and gaseous effluent on tritium among different countries are also presented, which may provide suggestions on the tritium treatment and disposal in future. Due to the small modular weight, the permeation and diffusion of tritium to the secondary circuit and the storage and disposal of H-3 liquid are worthy issues, which are investigated in current paper. The existing problems of tritium during cogeneration process of electricity and hydrogen are discussed as well. (author)