Actinide analysis

Actinides have significant abundance in irradiated nuclear fuel, long radioactive half-lives, and high radiological and chemical toxicities, and they raise concerns with criticality and nuclear proliferation. Accordingly, actinide analyses are important in process solutions, nuclear wastes, and environmental samples. 

Several groups have described the use of UTEVA-Resin separations coupled to ICP-MS for actinide analyses (see Table 9.4). UTEVA-Resin contains the extractant dipentyl pen-tylphosphonate (DP[PP]), which is also known as diamylamyl phosphonate (DAAP).31 This extractant retains actinides from nitric acid solutions as nitrato complexes, with increasing uptake as nitric acid concentrations increase (see Figure 9.11). Extraction equilibria for representative species are shown in Equations 9.6 and 9.7, where the bar above a species indicates that it is immobilized on the resin.4... 

Actinides analysis monitoring (e.g., uranium) Nuclear, remediation 51, 52... 

U(VI). The long separation column—preconditioned, loaded, and washed with 3 M HN03—was credited with the apparent retention of Np(V) and Am(III) under this elution program. These authors also examined UTEVA-Resin for this actinide analysis application but concluded that TRU-Resin was to be preferred for retention of actinides from urine. 

Tye, C. and Mennie, D., Actinide analysis with a novel high sensitivity ICP-MS. International Laboratory News, December 1994, p. 8. 

McLaughlin JP, Vintro LL, Smith KJ, MitcheU PI, Zunic ZS (2003) Actinide analysis of a depleted uranium penetrator from a 1999 target site in south Serbia J Environ Radioact 64 155-165... 

Potential fusion appHcations other than electricity production have received some study. For example, radiation and high temperature heat from a fusion reactor could be used to produce hydrogen by the electrolysis or radiolysis of water, which could be employed in the synthesis of portable chemical fuels for transportation or industrial use. The transmutation of radioactive actinide wastes from fission reactors may also be feasible. This idea would utilize the neutrons from a fusion reactor to convert hazardous isotopes into more benign and easier-to-handle species. The practicaUty of these concepts requires further analysis. 

The phosphido complex, Th(PPP)4 [143329-04-0], where PPP = P(CH2CH2P(CH2)2)2) has been prepared and fully characterized (35) and represents the first actinide complex containing exclusively metal—phosphoms bonds. The x-ray stmctural analysis indicated 3-3-electron donor phosphides and 1-1-electron phosphide, suggesting that the complex is formally 22-electron. Similar to the amido system, this phosphido compound is also reactive toward insertion reactions, especially with CO, which undergoes a double insertion (35,36). 

Electron Probe X-Ray Microanalysis (EPMA) is a spatially resolved, quantitative elemental analysis technique based on the generation of characteristic X rays by a focused beam of energetic electrons. EPMA is used to measure the concentrations of elements (beryllium to the actinides) at levels as low as 100 parts per million (ppm) and to determine lateral distributions by mapping. The modern EPMA instrument consists of several key components ... 

Equilibrium vapor pressures were measured in this study by means of a mass spectrometer/target collection apparatus. Analysis of the temperature dependence of the pressure of each intermetallic yielded heats and entropies of sublimation. Combination of these measured values with corresponding parameters for sublimation of elemental Pu enabled calculation of thermodynamic properties of formation of each condensed phase. Previ ly reported results on the subornation of the PuRu phase and the Pu-Pt and Pu-Ru systems are correlated with current research on the PuOs and Pulr compounds. Thermodynamic properties determined for these Pu-intermetallics are compared to analogous parameters of other actinide compounds in order to establish bonding trends and to test theoretical predictions. 

Reliable data on the thermodynamic and phase relationships of actinide oxide systems are essential for reactor safety analysis. This paper reviews certain aspects of thermodynamic data currently available on the nonstoichiometric Pu-0 system, which may serve as a basis for use in reactor safety analysis. Emphasis is placed on phase relationships, vaporization behavior, oxygen-potential measurements, and evaluation of pertinent thermodynamic quantities. 

The spectrometer was a Physical Electronics Model 548 modified for emplacement in a glovebox so that actinide samples could be examined. Spectra were taken using AIK radiation (1486.6 eV). The overall energy resolution of tne spectrometer was 1.2 eV using an analyzer pass energy of 25 eV. The spectrometer control was interfaced to a Nicolet 1180 minicomputer providing automatic data acquisition and analysis capability. 

As was the case with lanthanide crystal spectra (25), we found that a systematic analysis could be developed by examining differences, AP, between experimentally-established actinide parameter values and those computed using Hartree-Fock methods with the inclusion of relativistic corrections (24), as illustrated in Table IV for An3+. Crystal-field effects were approximated based on selected published results. By forming tabulations similar to Table IV for 2+, 4+, 5+ and 6+ spectra, to the extent that any experimental data were available to test the predictions, we found that the AP-values for Pu3+ provided a good starting point for approximating the structure of plutonium spectra in other valence states. However,... 

Calculations—See Data analysis Carbamoylmethylphosphoryl derivatives as actinide... 

DOE. 1995b. Separation and analysis of actinides by extraction chromatography coupled with alpha liquid scintillation spectrometry. Washington, DC U.S. Department of Energy. NTIS/DE96060013. 

Filipy RE, Khokhryakov VF, Suslova KG, et al. 1996. Comparisons of biokinetic models for actinide elements with observed tissue analysis data from occupationally-exposed humans of two countries. Health Phys 70(6)(Suppl.) S82. 

Qu H, Stuit D, Glover SE, et al. 1998. Preconcentration of plutonium and americium using the actinide-CLf resin for human tissue analysis. J Radioanal Nucl Chem 234(1-2) 175-181. 

In their subsequent analysis Baker and Bleaney (ibidem) decided to ignore the last term on the assumption that gdl 3b hv. Although this is a reasonable approximation for lanthanide and actinide integer-spin ions doped in single crystals, it is not usually an acceptable assumption for the broad-line spectra from metalloproteins. Furthermore, the assumption of a A-distribution around zero (i.e., D 0 but all other zero-field interaction parameters are zero) is equally untenable for biomolecules. Therefore, we go for a later extension of the theory, based on a full Equation 12.9 and on (A) 0, for application to metalloproteins (Hagen 1982b). 

In comparison with the lanthanides, the actinides show a more complex dependence of several properties on the atomic number an analysis, for instance, of the... 

The actual situation with regard to the purity of most of the actinide metals is far from ideal. Only thorixun (99), uranium 11,17), neptunium 20), and plutonium 60) have been produced at a purity > 99.9 at %. Due to the many grams required for preparation and for accurate analysis, it is probable that these abundant and relatively inexpensive elements (Table I) are the only ones whose metals can be prepared and refined to give such high purities, and whose purity can be verified by accurate analysis. The purity levels achieved for some of the actinide metals are listed in Table II. For actinium (Ac), berkelium (Bk), californium (Cf),... 

All subsequent preparations of Cf metal have used the method of choice, that is, reduction of californium oxide by La metal and deposition of the vaporized Cf metal (Section II,B) on a Ta collector 10, 30, 32, 45, 91, 97, 120). The apparatus used in this work is pictured schematically in Fig. 16. Complete analysis of Cf metal for cationic and anionic impurities has not been obtained due to the small (milligram) scale of the metal preparations to date. Since Cf is the element of highest atomic number available for measurement of its bulk properties in the metallic state, accurate measurement of its physical properties is important for predicting those of the still heavier actinides. Therefore, further studies of the metallic state of californium are necessary. 

Relatively few structural analysis of the decacoordinated lanthanide complexes have been reported. Although the lanthanides and actinides are long suspected as candidates for having decacoordination, it was not until 1965 that Lind, Lee and Hoard 211) were able to establish decacoordination for La(III) ion in monoclinic crystals of composition [La(EDTAH)] 7H2O. To date, only about ten or so decacoordinated structures are known, but many lanthanide complexes may have a coordination number of ten. 

Golchert NW, Iwami FS, Sedlet J. 1980. Determination of actinides in soil. In Lyon WS, ed. Radioelement analysis progress and problems. 23rd conference Analytical Chemistry in Energy Technology, Gatlinburg, TN, Oct 9-11, 1979. Ann Arbor, Ml Ann Arbor Science Publishers, Inc., 215-222. 

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