Usability of 124Sb-Be neutron source for rapid determination of uranium by delayed neutron method

Results of uranium determination by the methods of neutron activation analysis (NAA) and delayed neutrons (DN) are given. For activation of the samples 124Sb-Be neutron source with the yield of 3x109 neutrons was used. It is shown that for NAA detection of 239U by 74 keV photopeak using Ge(Li)-detector is the most conveniant one. The lower detection limit for uranium constituted 8x10-4%. Selection of the sample mass and optimal time for its cooling provides a possibility to decrease U detection limit. The DN method in contrast to NAA is more rapid and the measuring can be easier automated. A device for delayed neutrons detection is described. The lower detection limit of U is 1x10-3 mass% -1x10-3 mass% - 1x10-4 mass%, when the sample mass is 200 g. The NAA method permits to determine U in small weighed amounts (10 g), the analysis duration being 20-30 min. The DN method permits to determine U content in representative weighed amounts (100-200 g) in 3-4 min. Both methods are recommended for use in laboratories with powerful Sb-Be-sources. 7 refs.; 2 figs