The Analytical Determination And Its Application Of Gamma Ray Spectrum Relative Comparison Method For The Abundance Of Uranium-235 In Solid Uranium Materials

The analysis of uranium isotope abundance is very important in the production of nuclear fuel. At present, the gas mass spectrometry method has been widely used in the production of nuclear fuel, but the analysis of the enrichment of uranium isotope in the solid or liquid uranium material is mainly carried out by the method of chemical analysis. The chemical method is slow, time-consuming, low efficiency, and the error of the analytical results is large. It can only know the content of uranium in the material. The gamma energy spectrum is relatively simple, and the sample form is not limited, so it can be directly measured and analyzed, and it is a non-destructive measurement method.In this manuscript, using the high resolution gamma spectrometer for the solid or liquid uranium materials relative comparison method for the determination of U-235 abundance, of gamma can spectrometer to measure the sample container, the background count rate determination, energy calibration, the mighty peak efficiency calibration, instrument calibration, sample source preparation conditions were studied. The calculation to determine the sample analysis in the process of measurement time, correction factor, detection limit, relative error and uncertain parameters, the U-235 absolute quality and abundance calculation method of determine, and has carried on the comparative analysis to the actual sample, to verify its accuracy. The results of this study are as follows:(1) The relative standard uncertainty of the analysis and measurement for the determination of the purity of the uranium material sample is 6%;(2) The relative standard uncertainty of the analysis and measurement for the determination of the purity of the uranium material sample is 3.4%;(3) Experimental results show that the relative error of the whole measuring method is between ± 7%;(4) The detection limit of U-235 mass abundance can be up to 0.018%.By applying this method to the analysis of U3O8 powder material in the waste workshop, good results have been obtained. From the analysis results, the distribution range of U-235 mass abundance of U3O8 powder material in the waste workshop is from 0.72 to 21.48%. The results of the analysis of the mass abundance of U-235 in mixed samples are 5.24%, which meet the needs of users.