Behavior of Tritium Released to the Environment

Tritium release from a fusion reactor consists of chronic one during the normal operation and accidental one. Once tritium (T) is released from the reactor, it disperses into environment. Because of its low energy of the β-electron released at T decay, internal exposure by T uptake (inhalation and ingestion) and its biological effects are major concerns. Therefore, it is quite important to estimate and/or understand how dispersed T is finally uptaken in and impact human living in surrounding area. In this chapter, numerical models developed to estimate concentration in the environmental elements, and their distribution of T released from a fusion plant are described. The analysis of T behavior in the environment starts from determining source terms, then follow analyses of spatial transportation by advection and diffusion and migration among environmental elements (compartments), and estimates uptake into human body and finally evaluates dose.