Tritium release from irradiated beryllium at elevated temperatures

Tritium release kinetics have been measured for neutron-irradiated beryllium in the temperature range of 573-884 K. Two tritium release tests of 270 and 550 h are the first in a series of tritium release tests on irradiated Be in support of International Thermonuclear Experimental Reactor (ITER) blanket designs. Real-time tritium release curves were measured after temperature step changes of 100 K by an ionization chamber under conditions specific to ITER. The conditions and experiment were designed to measure diffusion-controlled release from irradiated Be. The preliminary conclusion from this data set is that a unique rate-controlling mechanism is not distinguishable. Apparent diffusion kinetics at lower temperatures give way to a burst release at 884 K, coincident with a restructuring and bubble coalescence in this fully dense material. (orig.)