Determination of radioactive iodine isotopes in the 99Mo product by distillation

For accurate assay of the radioactive iodine isotopes (131I, 132I, 133I) in the JAERI 99Mo product, the optimum conditions for distillation of iodine from the sulfuric acid solution containing hydrogen peroxide as an oxidizing agent have been examined. The distillation yield of iodine was influenced by the quantities of potassium iodide used as the carrier, ammonium molybdate and hydrogen peroxide. The distillation yield of iodine under optimum conditions is 99.6 +- 1.3%; 99Mo escaping from the mother liquor in the distillation flask into the trap is less than 10-4%. The time for complete assay is about 40 min. (author)