Abstract: This invention relates to a separation means and method for enriching a hydrogen atmosphere with at least one heavy hydrogen isotope by using a solid titaniun alloy hydride. To this end, the titanium alloy hydride containing at least one metal selected from the group consisting of vanadium, chromium, manganese, molybdenum, iron, cobalt and nickel is contacted with a circulating gaseous flow of hydrogen containing at least one heavy hydrogen isotope at a temperature in the range of -20.degree. to +40.degree. C and at a pressure above the dissociation pressure of the hydrided alloy selectively to concentrate at least one of the isotopes of hydrogen in the hydrided metal alloy. The contacting is continued until equilibrium is reached, and then the gaseous flow is isolated while the temperature and pressure of the enriched hydride remain undisturbed selectively to isolate the hydride. Thereafter, the enriched hydrogen is selectively recovered in accordance with the separation factor (S.F.