[en] Natural zeolite Analcime has been considered as a possible sorbent and storage material for tritiated water. The kinetics of tritiated water release from analcime crystals of two size fractions (20-50 and 50-80 μm dia.) into surrounding water has been investigated at 25-60 ⁰C. At 25 ⁰C the half-life of THO/H₂O exchange for the smaller and larger beads is about 1.3 and 5.0 hours, respectively. This is higher than the corresponding results obtained with synthetic analcime, but still of the same order of magnitude. The difference is ascribed to the presence of mineral impurities in natural analcime. If the natural mineral could be processed into particles of 2-5 mm radius, that material might be useful as a storage for tritiated waste water. 6 refs.; 3 figs