Interest in the transmutation of long-lived radioactive elements into stable or short-lived elements by means of nuclear reactions has increased sharply in the last few years. Specialists who support the practical application of methods for burning up radionuclides agree that efforts must first be focused on transuranium elements (237Np, 244Cm, 241Am, 241pu) as well as long-lived fission products, such as t29I and 99Tc [l, 2]. Radiation burnup of Np, Am and Cm and fission products with long half-lives is possible only after they are separated from the main mass of the spent fuel, including uranium and plutonium. Besides the main problem of eliminating an ecologically dangerous, long-lived radionuclide, transmutation of technetium will make it possible to obtain more stable ruthenium, which can then be used for industrial purposes.In studying methods for separating technetium from spent nuclear fuel, it becomes obvious that calcium pertechnetate obtained on an industrial scale (only at the Industrial Association NMayak') requires additional purification (even though it is of high radiochemical purity) in order to meet the requirements imposed on transmuted target preparations.According to the technical conditions, the content of radioactive impurities in 99Tc preparations should not exceed 0.024% of its own radioactivity. Radioactive impurities in technetium compounds were monitored on an ionizing-radiation spectrometer. In the course of this work new methods of preparation and analysis of especially pure technetium preparations were developed and tested.Data on the radiocbemical purity of industrial preparations of technetium are given in Table 1. The data were obtained by using methods which were developed for analytical monitoring.One can see from Table 1 that the main impurities in the 99Tc preparations are 98"1"c, l~ 137Cs, 238pu, 241Am, 239pu, 9~ Their content is at the level of 3.10 -4 of the radioactivity of 99Tc (radiochemical purity 99.9997%). Under production conditions, technetium preparations of higher purity cannot be obtained by technological schemes.To increase the radiochemical purity of technetium preparations, the initial potassium pertechnetate must be additionally purified by means of an optimal technological scheme for converting KTcO 4 into NH4TcO 4, which is the most acceptable form of the material for subsequent production of technetitun metal. When ammonium pertechnetate is reduced by hydrogen, only gaseous products and technetium metal are formed: NH4TcO 4 + 2H 2 ---, I/2N 2 + 4H20 + To. The conversion of KTcO 4 into NH4TcO 4 is possible on a KU-2 cation exchanger in an H + form followed by neutralization of the technetium acid by ammonia. Ammonium pertechnetate easily crystallizes from water solutions, which makes it possible to obtain this compound with a high purity.Extraction, ion-exchange, and precipitation methods for concentrating and removing from technetium the accompanying elements are well known and are described in detail in the literature. These methods can also be combined....
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.