Radiochemical Determination of Sodium-24 and Sulfur-35 in Seawater.

Abstract : Rapid radiochemical procedures were developed for determining Na-24 and S-35 in seawater containing fission product radionuclides. Na-24 is separated from other radionuclides by scavenging with lanthanum hydroxide; two NaCe precipitations with HCl gas follow. The disintegration rate is determined by measuring theAREA OF THE 1.368 Mev gamma photopeak. The working time required for a single analysis is 1/2 hr; the precision, !1%; the chemical yield, about 70%; and the total effective decontamination factor from fission products greater than 100,000. S-35 in seawater is separated from other radionuclides through precipitating BaSO4. This is followed by reducing the sulfate to H2S with HI and by subsequently oxidizing sulfide to sulfate in an alkaline peroxide solution. The resulting sulfate ion is precipitated as BaSO4 for chemical yield determination and counting. The working time required for a single analysis is less than 1 hr; the precision, !5%; the chemical yield, 70-80%; and the decontamination factor from fission products, greater than 10 to the 7th power. (Author)