The 59Ni and 55Fe radioisotopes were measured in radioactive wastes of some European nuclear power plants. A sample preparation method was developed that starts with the digestion in an oxygen atmosphere at an overpressure in a closed Berthelot calorimeter bomb. The detection limits for 59Ni and 55Fe were measured and calculated in the presence of high background activities from 60Co, 137Cs and 241Am isotopes.
Authors:Zs. Sándor, S. Tölgyesi, I. Gresits, and Zs. Kasztovszky
Isotope excited energy dispersive X-ray fluorescence (EDXRF) was used for the determination of the major components, silver and copper, of ancient coins. A ring shaped 125I source was used for excitation. Various methods were developed and compared for quantitative evaluation in order to eliminate matrix effects and the effects caused by the differences in geometry. The method proposed by the authors ensures determination with acceptable error using certified standard samples of alloys. The results of this method were compared with those of prompt gamma activation analysis (PGAA) and with data from contemporary written sources.
Authors:I. Gresits, S. Tölgyesi, L. Nagy, and J. Solymosi
A radioisotope-excited energy-dispersive X-ray fluorescence system has been constructed and used for the analysis of blood samples for trace elements. The possibility of determination of trace elements in blood by X-ray fluorescence based on comparison with standard reference materials has been outlined and the applicability of the method demonstrated by the analysis of blood samples. The method enables fast, non-destructive direct analyses to be carried out without lengthy sample pretreatment on a routine basis.
Authors:Zs. Sándor, S. Tölgyesi, I. Gresits, and M. Káplán-Juhász
Energy-dispersive X-ray fluorescence spectrometry was applied for the analysis of historical silver coins to determine the elemental composition in a fast and non-destructive way. Ag, Cu and trace elements (V, Cr, Mn, Fe, Co, Ni, Hg, Pd, Zr, Mo, Rh, Ru) were determined in coins of King Mathias (Hungary, 1458–1490). A new data evaluation technique was used to avoid the problems arising from the different sizes, surfaces and geometries. The appropriateness of this method was confirmed by analysing certified silver/copper standard alloys.
Authors:S. Tölgyesi, I. Gresits, T. Past, L. Szabó, G. Volent, and T. Pintér
An analytical procedure was developed for the alpha-spectrometric determination of uranium (238U, 235U, 234U) and transuranium isotopes (239+240Pu, 244Cm) in liquid radioactive wastes (sludges, evaporation residues) of low and medium activity from the VVER-440 reactor of the nuclear power plant in Paks, and in waste waters to be released into the environment. Radioactive sludge samples were separated to a liquid phase and a wet suspension (solid) phase by centrifuging, and the two phases were treated and analyzed separately, in different ways. A sample preparation procedure based on chemical separation was worked out for the isolation of the alpha-emitting components of radioactive evaporation residues which were saturated with boric acid. To the separate determination of the low activity alpha-emitting isotopes appearing in waste waters to be released into the environment, a microvawe concentration technique was applied. The accuracy of the results obtained using the above chemical separation and alpha-spectrometry was tested in the framework of the international U. S. DOE EML Quality Assessment Program.