Abstract: In this process, the decay heat of radioactive substances is carried away by circulating liquid coolant. Some of the liquid coolant is vaporized by the decay heat. The circulation of liquid in the circuit is driven by pressure from the vapor. After exceeding a static pressure head corresponding to the pressure drop in the circuit, the vapor is separated from the liquid and condensed, and the condensate is combined with the liquid returning for repeated partial vaporization.

Abstract: When reprocessing spent nuclear fuel, liquid radioactive wastes are obtained and within the wastes heat is generated from fission, and oxyhydrogen may be set free by radiolysis. The fission heat generated within the liquid wastes is carried off by evaporation cooling and, the vapor so formed is condensed and recycled into the storage vessel for the liquid wastes. The oxyhydrogen is then diluted with the vapor formed during evaporation cooling and converted catalytically.

Abstract: Gases resulting from the re-processing of spent nuclear fuel contain radioactive substances which are separated by mixing the said gases with a carrier gas having approximately the same separating behavior as the radioactive substances; the gas mixture obtained is separated into a fraction containing the radioactive substances and the carrier gas and a fraction free from these components. In a further stage the radioactive substances are separated from the carrier gas.

Abstract: Tritium formed in the treatment of spent nuclear fuel and during storage of liquid, radioactive waste products is retained by adding oxygen to said liquid, radioactive waste products, reducing in a subsequent stage the oxygen enriched with tritium and separating it from the tritium. The reduction can be carried out with NO. The higher nitrogen oxides formed can be reacted to nitric acid.

Abstract: Volatile, radioactive substances, obtained in the reprocessing of nuclear fuel and contained in the gas mixtures formed and in the liquid wastes are retained and separated in several stages. In the first stage the higher nitrogen oxides contained in the gas mixtures formed in the dissolution of the nuclear fuel with nitric acid and in the denitration of the uranium and plutonium nitrates are reduced to nitric oxide (NO) and iodine is absorbed. In the second stage, the gas mixture of the first stage is separated into a fraction containing the volatile, radioactive substances and nitric oxide and a fraction mainly consisting of nitrogen and xenon. Oxygen is added to the liquid, radioactive substances and enriched with volatile, radioactive substances. The enriched oxygen and the fraction of the second stage consisting of volatile, radioactive substances and nitric oxide are jointly subjected to a chemical treatment and the oxygen is reacted with the nitric oxide.

Abstract: In the reprocessing of spent nuclear fuel radioactive tritium is formed among others. Elemental tritium and/or tritium hydride can be stored without control provided that the generated heat is dissipated. To concentrate and separate tritium and/or tritium hydride, the tritium water obtained in the reprocessing of spent nuclear fuel is enriched with tritium hydroxide and di-tritium oxide by distillation and the mixture obtained is subjected to electrolysis.