Measurement of63Ni in highly radioactive Hanford waste by liquid scintillation counting
01 May 1994-Journal of Radioanalytical and Nuclear Chemistry (Akadémiai Kiadó, co-published with Springer Science+Business Media B.V., Formerly Kluwer Academic Publishers B.V.)-Vol. 180, Iss: 2, pp 197-200
TL;DR: In this paper, a method for determining high-activity radioactive waste stored in underground tanks at Hanford requires determining 63Ni (100 y), a low-energy β-emitter (Emax 67 keV).
Abstract: Characterization of high-activity radioactive waste stored in underground tanks at Hanford requires determining63Ni (100 y). This low-energy β-emitter (Emax 67 keV) must be separated with a high degree of radiochemical purity large amounts of other fission and activation products. The method to be discussed involves multiple precipitation steps with several holdback carriers added, followed by precipitations with dimethylglyoxime, ion exchange, and electrodeposition. The59Ni activity is determined by low-energy photon spectrometry. The sample is then stripped from the counting disk with HNO3, converted to the chloride form, and the63Ni β-spectrum is measured with high efficiency by liquid scintillation counting.
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TL;DR: These methods are critically compared for the determination of long-lived radionuclides important for radiation protection, decommissioning of nuclear facilities, repository of nuclear waste, tracer application in the environmental and biological researches.
314 citations
TL;DR: In this paper, an analytical method for the determination of 63 Ni and 55 Fe in nuclear waste samples such as graphite, heavy concrete, aluminium and lead was developed, where different decomposition methods (i.e. ashing, acid digestion and alkali fusion) were investigated for the decomposition of the samples and for the separation of Fe and Ni from the matrix.
70 citations
01 Jan 2012
TL;DR: In this article, the principles of ultralow-level liquid scintillation spectrometers are introduced and the sources of background signals and the means to reduce background are discussed.
Abstract: Principles of ultralow-level liquid scintillation spectrometers are introduced in this chapter. The sources of background signals and the means to reduce background are discussed. Electronic pulse discrimination and anticoincidence counting allow the determination of low radioactivities and the separation of α- and β-events into their respective spectra. These features make liquid scintillation counting (LSC) methods practical for simultaneous detection of low α and β activities in environmental samples, which are described. LSC methods are presented and discussed for 3 H, 14 C, 63 Ni, 89 Sr, 90 Sr/ 90 Y, and 99 Tc, transuranium elements including plutonium and for most important natural radionuclides, 222 Rn, Ra, U and Th isotopes, and 210 Pb and 210 Po. Because the radiation exposure from environmental radioactivity arises largely from natural radionuclides, the importance of their analyses is discussed along with the sensitive methods used for their analysis. A section is devoted to radiometric methods to differentiate between biogenic and fossil 14 C in fuels. Spectrum unfolding or deconvolution of low-activity α-spectra is discussed.
37 citations
TL;DR: A simple and rapid separation procedure was systemized for the determination of 99Tc, 90Sr, 94Nb, 55Fe and 59,63Ni in low and intermediate level radioactive wastes as discussed by the authors.
Abstract: A simple and rapid separation procedure was systemized for the determination of 99Tc, 90Sr, 94Nb, 55Fe and 59,63Ni in low and intermediate level radioactive wastes. The integrated procedure involves precipitation, anion exchange and extraction chromatography for the separation and purification of individual radionuclide from sample matrix elements and from other radionuclides. After separating Re (as a surrogate of 99Tc) on an anion change resin column, Sr, Nb, Fe and Ni were sequentially separated as follows; Sr was separated as Sr (Ca-oxalate) co-precipitates from Nb, Fe and Ni followed by purification using Sr-Spec extraction chromatographic resin. Nb was separated from Fe and Ni by anion exchange chromatography. Fe was separated from Ni by anion exchange chromatography. Ni was separated as Ni-dimethylglyoxime precipitates after the removal of 134,137Cs and 110mAg by Cs-phosphotungstate and AgCl precipitation, respectively. Finally, the radionuclide sources were prepared by precipitation for their radioactivity measurements. The reliability of the procedure was evaluated by measuring the recovery of chemical carriers added to a synthetic radioactive waste solution.
18 citations
TL;DR: A sequential separation procedure has been developed for the determination of 99Tc, 94Nb, 55Fe, 90Sr and 59/63Ni in various radioactive wastes generated from nuclear power plants.
Abstract: A sequential separation procedure has been developed for the determination of 99Tc, 94Nb, 55Fe, 90Sr and 59/63Ni in various radioactive wastes generated from nuclear power plants. Ion exchange and extraction chromatography were adopted for individual separation of the radionuclides. Precipitation was supplementarily utilized for both purification of the individual radionuclides and preparation of the radionuclide sources for use in a radioactivity measurement. The chromatographic separation behavior of the radionuclides both from the sample matrix metals and from one another was investigated using stable metals, Re (as a surrogate of 99Tc), Nb, Fe, Sr and Ni. The validity of the procedure for reliability and applicability was evaluated by measuring the recovery of the metal carriers added to synthetic radioactive waste solutions. The recoveries by the chromatographic separation were in the range of 84.8 to 102.2% with 2s of less than 8.6%, the recoveries by the precipitation being in the range of 84.3 to 97.3% with 2s of less than 10.9%.
17 citations
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TL;DR: The method used involves anion exchange, precipitation of the Ni as Ni-dimethyl glyoxime complex, and a gel scintillation counting technique for $sup 63$Ni measurement.
Abstract: Nickel-63 is separated from other radionuclides in environmental samples containing various fission and activation products. The method used involves anion exchange, precipitation of the Ni as Ni-dimethyl glyoxime complex, and a gel scintillation counting technique for $sup 63$Ni measurement. (auth)
11 citations