Analyzing alpha emitting isotopes of Pu, Am and Cm from NPP water samples: an intercomparison of Nordic radiochemical laboratories (original) (raw)
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Determination of alpha-emitting Pu isotopes in environmental samples
The Analyst, 2002
This paper presents an improved radiochemical procedure for the determination of alpha-emitting Pu isotopes in environmental samples (soils, sediments, vegetation) by alpha-particle spectrometry. Quantitative Pu recovery yields were obtained (average 60%), 0.1 mBq being the average minimum detectable activity by the complete technique. Special efforts were made to ensure the removal of traces of different natural alpha-emitting radionuclides, which can interfere with the correct determination of 239+240 Pu and 238 Pu concentrations. The radiochemical procedure was validated by application to reference material and by participation in intercomparison exercises. This radiochemical procedure was applied to the different layers of a high-resolution sediment core taken from a lake in Sweden. The 239+240 Pu and 238 Pu/ 239+240 Pu profiles obtained in the high-resolution sediment core correctly reproduced the expected evolution of these quantities as observed historically in the atmosphere, validating the procedure for this purpose and showing the power of these radionuclides for dating purposes.
Determination of uranium, thorium and plutonium isotopes by ICP-MS
Journal of Radioanalytical and Nuclear Chemistry, 2012
Quantitative and isotopic measurement of actinide elements is required in many circumstances in the nuclear industry. For example, determination of very low levels of these alpha emitters in human urine samples is used to assess the internal committed dose for nuclear workers. Quantifying actinide isotopes in radioactive waste from nuclear processing and nuclear facility decommissioning provides important information for waste management. Accurate determination of the uranium isotopic ratios in reactor fuels provides fuel burnup information. Inductively coupled plasma mass spectrometry (ICP-MS) has been used for the determination of Th, U, and Pu in various samples including urine, nuclear waste, and nuclear fuel in our laboratory. In order to maximize the capability of the technique and ensure quality analyses, ICP-MS was used to analyze samples directly, or after pre-treatment to separate complicated matrices or to concentrate the analyte(s). High-efficiency sample introduction techniques were investigated. Spectral interferences to minor isotopes caused by peak tails and hydride ions of major actinide isotopes were studied in detail using solutions prepared with light and heavy waters. The quality of the isotopic ratio measurement was monitored using standard reference materials. Keywords Actinides Á Isotopes Á ICP-MS Á Bioassay Á Internal committed dose Á Radioactive waste Á Nuclear fuel
NKS Secretariat, 2021
In a previous NKS project "OPTIMETHOD" (2018-2019), an optimised method was presented for separation of Pu, Am and Cm isotopes from NPP reactor water samples. This separation method was tested in an intercomparison organised in 2020 with two solid sample matrices, lichen sample and IAEA-384 reference material, for expanding its usability. The goal of the RAD-MERDE project was to provide an alternative, novel method to previously used fairly established methods for separating actinide isotopes from e.g. environmental and nuclear decommissioning samples. The tested separation method includes iron hydroxide coprecipitation of actinide isotopes and radiochemical separation of Pu and Am with extraction chromatography resins TEVA and DGA. The obtained practical experiences and analytical performance for Pu and Am are discussed in this report and the findings suggest that the development and testing of the separation method should be continued with more solid sample materials.
2013
The characterization of the liquid effluents means identifying the source, the physical and chemical properties and the radionuclide inventory. In general, the determination of actinides involve complex chemical analysis to separate them from the matrix, as they are mainly alpha emitters and the samples for the alpha spectrometer must be thick and without other impurities or interfering nuclides. This paper presents the tests performed in the Laboratory for Radioprotection, Environmental Protection and Civil Protection, RAAN-SCN, Piteşti, Romania, for the implementation of the Eichrom® procedure for sequential determination of actinides in liquid effluents. The validation of the results was performed by determining the activities using two different methods, alpha spectrometry and liquid scintillation counting.
Determination of plutonium in environmental samples by AMS and alpha spectrometry
Applied Radiation and Isotopes, 2005
Environmental samples from nuclear weapons test sites at the atolls of Mururoa and Fangataufa (French Polynesia, south Pacific) have been analyzed for their content of plutonium isotopes by applying the independent techniques of decay counting (Alpha Spectrometry) and accelerator mass spectrometry (AMS). Here, we propose the combination of both techniques which results in a maximum of information on the isotopic signature of Pu in environmental samples.
Czechoslovak Journal of Physics, 2006
A sequential extraction technique was developed and tested for common naturally-occurring radionuclides. This technique allows the extraction and purification of uranium, thorium, radium, lead, and polonium radionuclides from the same sample. Environmental materials such as water, soil, and biological samples can be analyzed for those radionuclides without matrix interferences in the quality of radioelement purification and in the radiochemical yield. The use of isotopic tracers ( 232 U, 229 Th, 224 Ra, 209 Po, and stable lead carrier) added to the sample in the beginning of the chemical procedure, enables an accurate control of the radiochemical yield for each radioelement. The ion extraction procedure, applied after either complete dissolution of the solid sample with mineral acids or co-precipitation of dissolved radionuclide with MnO 2 for aqueous samples, includes the use of commercially available pre-packed columns from Eichrom® and ion exchange columns packed with Bio-Rad resins, in altogether three chromatography columns. All radioactive elements but one are purified and electroplated on stainless steel discs. Polonium is spontaneously plated on a silver disc. The discs are measured using high resolution silicon surface barrier detectors. 210 Pb, a beta emitter, can be measured either through the beta emission of 210 Bi, or stored for a few months and determined by alpha spectrometry through the in-growth of 210 Po. This sequential extraction chromatography technique was tested and validated with the analysis of certified reference materials from the IAEA. Reproducibility was tested through repeated analysis of the same homogeneous material (water sample).
A critical evaluation of different isotope correlations for the determination of 242Pu
Applied Radiation and Isotopes, 2010
Different correlations are evaluated for the determination of 242 Pu in Pu generated from PHWR reactors with an average burn-up of about 10,000 MWd/TU. It is shown that the correlations involving ratios of Pu isotopes, except for 241 Pu, provide data with better confidence compared with those involving the atom% abundance. These correlations are also attractive when the decay period of the given sample is not known. In addition, it is shown that instead of using 239 Pu atom% abundance alone (Swinhoe et al., 2010), either 240 Pu atom% or a linear combination of 239 Pu and 240 Pu gives abundance of 242 Pu with better reliability. The uncertainty due to different decay periods also remains unaffected when using the correlation involving both 239 Pu and 240 Pu atom%. The present conclusions are based on Pu isotopic composition data from PHWR reactors (239 Pu 65-75%) whereas those reported by other investigators are for PWR and BWR types of reactors.
2015
The NKS-B STANDMETHOD project was launched in January 2014, aiming to standardize the radioanalytical method for the determination of important radionuclides difficult to measure in Nordic industry. The present status of radioanalysis in Nordic laboratories is reviewed and presented in this report. A review article on this topic was prepared to be published in a peer review journal, and an intercomparison exercise was implemented for determination of 63 Ni and 55 Fe in three types of water samples: spiked water, reactor coolant water and an acid digested filter from a nuclear reactor. Seven labs participated in the intercomparison and reported their analytical results of 63 Ni. Different analytical methods used by the labs, and the results are discussed in this report. The intercomparison results for 63 Ni agree relatively well for the spiked water, but a big variation of the results was observed for the real reactor coolant water and for the digested filter sample. This indicates that the methods used in some labs could not remove interfering nuclides to a sufficient extent. An improvement of the analytical method of some labs and a follow-up intercomparison exercise are proposed.