Tritium sorption by cement and subsequent release

In a fusion reactor or tritium-handling facilities, contamination of concrete by tritium and subsequent release from it to the reator or experimental room is a matter of problem for safe control of tritium and management of operational environment. In order to evaluate this tritium behavior, interaction of tritiated water with concrete or cement should be clarified. In the present study, HTO sorption and subsequent release from cement were experimentally studied. 1. rption experiments were conducted using columns packed with cement particles of different sizes. From the analysis of the breakthrough curve, tritium diffusivity in macropores and microparticles were evaluated. om the short-term tritium release experiments, effective desorption rate constants were evaluated and the effects of temperature and moisture were studied. the long-term tritium release experiments to 6000 h, the tritium release mechanism was found to be composed of three kinds of water: initially from capillary water, and in the second stage from gel water and from the water in the cement crystal. itium release behavior by heat treatment to 800°C was studied. A high temperature above 600°C was required for the tritium trapped in the crystal water to be released.