Abstract: Method of determining the activity concentration of the radio nuclides in waste gases of nuclear power plants by bleeding a part of the gas stream, compressing it to a high superatmospheric pressure, passing the compressed gas into a high pressure chamber where the specific nuclides are measured by means of a calibrated Ge (Li) detector, and returning the gas from the chamber at reduced pressure to the gas stream. The activity concentration of the gas in the high-pressure vessel permits measurement of the specific nuclides, and also permits detection of waste gas activities which are below the customary detection limits.

Abstract: For zone-wise shuffling of the fuel elements of a nuclear reactor core, single ones of the elements, one after another, are removed sequentially, and immediately upon the removal of each element it is tested for cladding defects, and if free therefrom, immediately inserted back in its new position in the reactor core, elements having cladding defects being eliminated. An apparatus for the rapid testing of each removed element is provided by a testing chamber containing water in which the removed element is immersed and allowed to remain for a short time, the water then being removed and tested for gamma activity to determine the element's cladding integrity. Other features are disclosed.

Abstract: A process for producing selenium homogeneously doped with a metal. The process comprises mixing the metal with selenium, melting the selenium and mixing the resulting melt in the absence or substantial absence of oxygen or with the extraction of any oxygen or oxide contained in the melt so as to produce selenium homogeneously doped with the metal.