Tritium fractionation on the crystal growth of sodium sulfate decahydrate from its tritiated aqueous solution

Abstract The fractionation of tritiated water (HTO) was examined during the crystallization of sodium sulfate decahydrate, Na2SO4·10H2O, from a slightly supersaturated solution which contained a trace amount of tritium. No appreciable fractionation of HTO was found to occur in the crystallization under both stirred and unstirred conditions. The factors which may influence the degree of the fractionation were generally considered in connection with the studies by deuterated water. It was suggested that virtually all of the water of crystallization in sodium sulfate decahydrate should come from free water in its aqueous solution, and should integrate into the crystal in accordance with the volume-diffusion model. This model was supported also by the energetical consideration of the sodium ion in the crystallization.