A new fecal analysis method that dissolves plutonium oxide was developedat the Westinghouse Savannah River Site. Diphonix Resin . (Eichrom Technologies),is used to pre-concentrate the actinides from digested fecal samples. A rapidmicrowave digestion technique is used to remove the actinides from the DiphonixResin ., which effectively extracts plutonium and americium from acidic solutionscontaining hydrofluoric acid. After resin digestion, the plutonium and americiumare recovered in a small volume of nitric acid that is loaded onto small extractionchromatography columns, TEVA Resin and TRU Resin (Eichrom Technologies). Themethod enables complete dissolution of plutonium oxide and provides high recoveryof plutonium and americium with good removal of thorium isotopes such as 228Th.
Authors:Yu. Novikov, V. Gliva, S. Ivanova, and B. Myasoedov
Determination of microamounts of plutonium isotopes by luminescent radiation in the infra-red region of PbMoO4 crystallophosphors activated by plutonium is proposed. The determination is possible against the background of subtantial amounts of uranium, iron, rare earths and other elements. The detection limit of plutonium is 10–9 g in the samples tested. The accuracy is 0.1 for a confidence level of 0.95.
A recent paper about plutonium disproportionation confuses charge balance with charge conservation. To explain disproportionation, impossible solutions in which the charges do not balance were proposed.
The results of plutonium oxidation state distribution calculations do not depend on special attention to any oxidation state as has been incorrectly supposed in some literature sources. Experimentally determined alpha coefficients for natural water could make the distribution of environmental plutonium easy to estimate with a programmable pocket calculator.
A surface representing the work needed to oxidize trivalent plutonium to the hexavalent state can be described in terms of
the pH and the equilibrium fraction of hexavalent plutonium in the solution. The surface has a trough. Its depth and locus
depend on the pH and the fraction of the Pu(VI).
Plutonium/IV/ compounds obtained in the reactions with phenylacetic acid and -naphthyl acetic acid in the pH range of 3.5–5.0 have been isolated and studied. Carbon, hydrogen and plutonium analyses have shown that plutonium/IV/ phenyl acetate and plutonium/IV/ -naphthyl acetate have the composition Pu/OH/3/C10H7CH2COO/, respectively. Infra-red and ultra-violet absorption spectral studies and thermogravimetric analysis have corroborated these chemical formulas.
The sorption of Pu(IV), polymeric Pu(IV), Pu(V) and Pu(VI) from the 0.1 M NaClO4 solution onto multiwalled carbon nanotubes was investigated. The kinetic study of the sorption process have shown that the
polymeric Pu(IV) has the highest sorption rate, while decrease of sorption rate for plutonium aqua-ions in the order Pu(VI) > Pu(IV) > Pu(V)
was found. Strong dependence of sorption kinetics of ionic plutonium species on pH was shown, in contrast to polymeric species,
that were shown to quantitatively sorb (99%) in the wide pH range (pH 2–10). Two different sorption mechanisms for ionic and
polymeric plutonium species were proposed: on the bases of sorption isotherms chemisorptions of plutonium aqua-ions onto carbon
nanotubes and through intermolecular interaction for the polymeric plutonium species was defined. Distribution coefficients
of plutonium in various oxidation states were found to increase with pH, showing the highest values for polymeric plutonium
sorption (Kd = 2.4 × 105 mL g−1 at pH = 6).
Authors:C. Greis, A. Düker, B. Allard, P. Roos, and E. Holm
Fresh water from Lake Svartsjön, Sweden, was collected and four fractions were prepared: (1) adsorption on DEAE, (2) flocculation
with Ca2+, (3) co-precipitation with Fe hydrous oxide and (4) co-precipitation with Mn hydrous oxide. The plutonium level in the lake
is 65 fg/l (222 μBq/l), measured by ICP-QMS and ICP-SFMS. Pronounced accumulation in fractions (1) (34%) and (2) (66%), combined
with observed levels of organic matter indicate that plutonium is predominantly associated with organic matter. Measurements
of isotopic ratios indicate that 77% of the plutonium originates from weapons testing and the remaining appears to originate
from the Chernobyl accident.
The experience with the determination of plutonium and uranium in the samples of nuclear fuel obtained during a 10-years period of the activity of the Central Control Laboratory of the Nuclear Research Institute at e is evaluated. The paper describes the principles of the methods used and the reproducibilities and accuracies of the results obtained with the aid of the titrimetric methods used for the determination of plutonium and uranium.
Analytical and statistical uncertainties associated with low-level measurements may lead to spurious conclusions regarding the behavior of some plutonium isotopes. The general aspect of the methodology used in sample collection, preparation, radiochemical separation and alpha spectroscopy analysis of plutonium is considered. Biases and experimental artifacts that may produce inaccurate results and improper conclusions are discussed with examples from our research and from the open literature.