Kuniaki Watanabe, Masao Matsuyama, Kan Ashida, Toyosaburo Takeuchi

Tritium Research Center, Toyama University, Gofuku 3190, Toyama 930, Japan

Osamu Takayasu, Ikuro Makino, Toyosaburo Takeuchi

Faculty of Science, Toyama University, Gofuku, Toyama, Japan

Abstract

    Tritium present in H₂ or D₂ 1.7×10^-2 Ci/mol, was enriched using a hot-wire type vertical glass thermal-diffusion column with a gas reservoir on top. Four columns with different diameters (mmΦ), 8, 20, 30 and 41, were tested, while the temperature of a DC heated nichrome wire along the axis of each column was changed over a range from 200 to 450℃. The maximum equilibrium separation factors in hydrogen and in deuterium were 17 and 4.5 respectively. The optimum diameters were calculated by a modification of Waldmann's equation which can be used for the separation using parallel plates.

Masao Matsuyama, Toyosaburo Takeuchi

Tritium Research Center, Toyama University

Abstract

    The ability of trapping of tritium by silica and alumina which were preliminarily doped with Li and irradiated with neutrons, and the removal of tritium from these materials by ethylene were investigated. Tritium formed in almina was not liberated by the elevation of temperature to 350℃. Tritium in silica was very slightly liberated at above 250℃. The trap of tritium by silica and alumina was explained in terms of the exchange reaction of hydrogen of OH and the bounding of tritum with oxygen produced freshly by the radiation damage. Tritium in silica was removed in the form of T-ethylene at 300℃ and that in alumina at 100℃. The doping of 10% Ni to silica and alumina promoted the liberation of tritium gas and the formation of T-compounds. The promotion of these reactions were explained in terms of "reversing spillover".

Keywords: traps; tritium; removal silica; alumina; exchange reaction; temperature dependence; ethylene; leaks