Authors:R. Bhanushali, Sachin Pathak, I. Pius, and S. Mukerjee
Porous zirconia spherical particles have been prepared by internal gelation process. During preparation of these spherical
particles, a cationic surfactant, cetrimide was added in the feed broth to increase the surface area and porosity of the particles.
The sorption behavior of plutonium was investigated on this material from different complexing aqueous media from the recovery
point of view. Distribution ratio studies have been carried out to investigate the effect of varying concentrations of oxalic
acid, phosphoric acid, sulphuric acid, nitric acid, sodium carbonate and sodium bicarbonate to optimize the conditions of
sorption of plutonium on this ion exchange material.
Authors:B. Srinivasan, K. Mathew, U. Narayanan, W. Guthrie, and T. Sampson
The calorimetry exchange (CALEX) program is administered by New Brunswick Laboratory (NBL). The main objective of the program
is to provide an independent verification of the internal quality control practices in nuclear material safeguards facilities
making plutonium accountability measurements by non-destructive calorimetry/gamma spectrometry techniques. Facilities measure
the calorimetric power, and plutonium and 241Am isotope abundances of CALEX program standards using routine accountability procedures. The measurement results as well
as two other quantities (effective specific power and plutonium mass) calculated from these results are evaluated for accuracy
(or bias) and precision. In this paper, a limited number of measurement results of a CALEX program standard (identified as
Calex I) are evaluated with specific goals to identify a suitable method for uncertainty estimation and to identify the major
contributors to the uncertainties. In order to achieve the goals, the Calex I measurement results were evaluated using two
different methods: the first method confined to uncertainty estimation from random variations of the measurement results alone,
and the second method providing a more comprehensive evaluation of uncertainties from both the measurements and the characterized
values of the measured standard according to the Guide to the Expression of Uncertainty in Measurement (GUM). The results
of this study, and a subsequent study extended to a larger number of results in the CALEX program database, are expected to
provide relevant input for developing the International Target Values for plutonium measurements by the calorimetry/gamma
Authors:K. Gupta, Suman Singh, G. Inamdar, A. Madhusudan, and S. Tripathi
This paper deals with the studies on decontaminations of spent ion exchange resin used for purification of plutonium in PUREX
process stream. Studies were carried out to optimize the chemical procedure for removal of plutonium and fission products
activities form spent Ion Exchange resin. Different metal complexing reagents were tested for leaching out of radionuclides
entrapped in irradiated spent ion exchange resin. The experimental results indicate that 0.01 M NaF solution was found the
most suitable for removal of plutonium. The mixture of Na2CO3 and sodium salt of EDTA solution was found to be better for decontamination of spent ion exchange resin from beta and gamma
activities. Optimized mixture of 0.5 M Na2CO3 and 0.1 M sodium salt of EDTA solution was found to be the most effective for fission product activities removal. After successive
multiple contacts using these suitable reagents, the Pu and fission product activities in spent ion exchange resin were brought
down to a minimum possible level, making it quite suitable for its long term storage.
Minimizing plutonium measurement uncertainty is essential to nuclear material control and international safeguards. In 2005,
the International Organization for Standardization (ISO) published ISO 12183 “Controlled-potential coulometric assay of plutonium,”
2nd edition. ISO 12183:2005 recommends a target of ±0.01% for the mass of original sample in the aliquot because it is a critical
assay variable. Mass measurements in radiological containment were evaluated and uncertainties estimated. The uncertainty
estimate for the mass measurement also includes uncertainty in correcting for buoyancy effects from air acting as a fluid
and from decreased pressure of heated air from the specific heat of the plutonium isotopes.
A flow injection-based electrochemical detection system coupled to a solid-phase extraction column was developed for the determination
of trace amounts of plutonium in low-active liquid wastes from spent nuclear-fuel reprocessing plants. The oxidation state
of plutonium in a sample solution was adjusted to Pu(VI) by the addition of silver(II) oxide. A sample solution was made up
in 3 mol L−1 HNO3 and loaded onto a column packed with UTEVA® with 3 mol L−1 HNO3 as the carrier. Plutonium(VI) was adsorbed onto the resin, and interfering elements were removed by rinsing the column with
3 mol L−1 HNO3. Subsequently, the adsorbed Pu(VI) was eluted with 0.01 mol L−1 HNO3, and then introduced directly into the flow-through electrolysis cell with boron-doped diamond electrode. The eluted Pu(VI)
was detected by an electrochemical amperometric method at a working potential of 0.1 V (vs. Ag/AgCl). The current produced
on reduction of Pu(VI) was continuously monitored and recorded. The plutonium concentration was calculated from the relationship
between the peak area and concentration of plutonium. The relative standard deviation of ten analyses was 1.1% for a plutonium
solution of 25 μg L−1 containing 50 ng of Pu. The detection limit calculated from three-times the standard deviation was 0.82 μg L−1 (1.6 ng of Pu).
Authors:R. Martinelli, T. Hamilton, R. Williams, and S. Kehl
Uranium (U) and plutonium (Pu) isotopes in coral soils, contaminated by nuclear weapons testing in the northern Marshall Islands,
were isolated by ion-exchange chromatography and analyzed by mass spectrometry. The soil samples were spiked with 233U and 242Pu tracers, dissolved in minerals acids, and U and Pu isotopes isolated and purified on commercially available ion-exchange
columns. The ion-exchange technique employed a TEVA® column coupled to a UTEVA® column. U and Pu isotope fractions were then further isolated using separate elution schemes, and the purified fractions
containing U and Pu isotopes analyzed sequentially using multi-collector inductively coupled plasma mass spectrometer (MCICP-MS).
High precision measurements of 234U/235U, 238U/235U, 236U/235U, and 240Pu/239Pu in soil samples were attained using the described methodology and instrumentation, and provide a basis for conducting more
detailed assessments of the behavior and transfer of uranium and plutonium in the environment.
Authors:Fabienne Luisier, José Corcho Alvarado, Philipp Steinmann, Michael Krachler, and Pascal Froidevaux
Plutonium and americium are radionuclides particularly difficult to measure in environmental samples because they are α-emitters
and therefore necessitate a careful separation before any measurement, either using radiometric methods or ICP-SMS. Recent
developments in extraction chromatography resins such as Eichrom® TRU and TEVA have resolved many of the analytical problems but drawbacks such as low recovery and spectral interferences
still occasionally occur. Here, we report on the use of the new Eichrom® DGA resin in association with TEVA resin and high pressure microwave acid leaching for the sequential determination of plutonium
and americium in environmental samples. The method results in average recoveries of 83 ± 15% for plutonium and 73 ± 22% for
americium (n = 60), and a less than 10% deviation from reference values of four IAEA reference materials and three samples
from intercomparisons exercises. The method is also suitable for measuring 239Pu in water samples at the μBq/l level, if ICP-SMS is used for the measurement.
Authors:Lav Tandon, Kevin Kuhn, Patrick Martinez, Joseph Banar, Laurie Walker, Terry Hahn, David Beddingfield, Donivan Porterfield, Steven Myers, Stephen LaMont, Daniel Schwartz, David Gallimore, Scott Garner, Khalil Spencer, Lisa Townsend, Heather Volz, Russ Gritzo, Rodney McCabe, Ramiro Pereyra, Dominic Peterson, Mark Scott, Christy Ruggiero, Diana Decker, and Amy Wong
This paper presents results from the examination of a number of archived neutron-irradiated uranium targets used for past
plutonium production testing. Three of these targets were destructively characterized using Los Alamos National Laboratory
actinide analytical chemistry capabilities. A validated conduct-of-operations protocol was followed for this characterization
effort. Chemical analyses included measurements for radionuclides, uranium assay, uranium isotopic abundances, trace actinides,
trace metals, and non-metals. Material scientists also examined materials for morphological and microstructural properties
and individual particles were examined for trace impurities. After characterization of the targets was completed, a reactor
modeling effort was undertaken to corroborate target details in historical records. Time since irradiation calculations utilized
both activation and fission products. The described examination of uranium targets has a tremendous impact from a safeguards
verification and nuclear forensics perspective.
Authors:Wei Dong, Jian Zheng, Masatoshi Yamada, and Qiuju Guo
The anthropogenic plutonium isotopes are important geochemical tracers for environmental studies. The distributions and sources
of the Pu isotopes in water column or sediments of the North Pacific have been intensively studied. However, knowledge on
the distribution of Pu isotopes in sediments of the Central Pacific, when available, is limited. To study the composition
of Pu isotopes in the ocean, thus to identify the sources of radioactive pollution, sediment core samples were collected in
the Central Pacific by R/V Hakuho Maru in the KH-04-5 cruise. The activity concentrations of 239+240Pu and the 240Pu/239Pu atom ratio were determined using a sector-field inductively coupled mass spectrometry (SF-ICP-MS) combined with a high
efficiency sample introduction system (APEX-Q). Possible sources and sedimentation behavior of Pu isotopes are discussed.
The simultaneous determination of actinides in air filter and water samples around the WIPP site have been demonstrated. The
analytical method is based on the selective separation and purification by anion exchange and Eichrome-TEVA, TRU and DGA-resin
followed by determination of actinides by alpha spectrometry. Counting sources for alpha spectrometric measurements were prepared
by microcoprecipitation on neodymium fluoride (NdF3). Radiochemical yields were determined using 242Pu, 229Th, 243Am and 232U as tracers. The validation of the method is performed through the analysis of reference materials or participating in laboratory
intercomparison programs. The plutonium concentrations in aerosols varied seasonally, being highest in spring and summer due
to the spring-time enhanced wind-storm transportation of radioactive aerosols from the stratosphere to the troposphere. The
238Pu/239+240Pu activity ratio in the aerosol samples is typically close to that of global fallout from historic above-ground nuclear weapons
testing. The results presented here indicate that the source of plutonium in the WIPP environment results mainly from global
nuclear fallout and there is no evidence of increases in radiological contaminants in the region that could be attributed
to releases from the WIPP.