Pu Isotopes Research Articles

Power Source based on Al-=SUB=-0.8-=/SUB=-Ga-=SUB=-0.2-=/SUB=-As/GaAs photovoltaic converter and YPO-=SUB=-4-=/SUB=- : Eu/(-=SUP=-238-=/SUP=-Pu) radioluminescent emitter

An AlGaAs/GaAs photovoltaic converter for a mock-up of an environmentally friendly radioisotope energy source of ultra-long use with a YPO4 : Eu/(238Pu) radioluminescent emitter with an extremely low content of the isotope 238Pu<0.1 wt.% was studied. The modeling of the Al0.8Ga0.2As/GaAs heterostructure for the conversion of nanowatt power levels of an optical signal has been carried out. The calculated and experimental efficiency of the mock-up with a photovoltaic converter at a radioluminescent source power of 1 nW was ~1.4%. Keywords: radioisotope energy source, AlGaAs/GaAs photo converter, optical radiation radioluminescent source, current flow mechanisms, conversion efficiency.

Unveiling the extreme environmental radioactivity of cryoconite from a Norwegian glacier

This study is a first survey of the occurrence of artificial (137Cs, 241Am, 207Bi, Pu isotopes) and natural (210Pb, 228Ac, 214Bi, 40K) radionuclides in Norwegian cryoconite. Cryoconite samples were collected before (12 samples) and after (5 samples) a rainfall event, after which 7 cryoconite holes dissapeared. The concentrations of radionuclides in cryoconite samples from the Blåisen Glacier are compared with data from the Arctic and Alpine glaciers. Cryoconite samples from the studied glacier had extremely high activity concentrations of 137Cs, 241Am, 207Bi and 239+240Pu (up to 25,000 Bq/kg, 58 Bq/kg, 13 Bq/kg and 131 Bq/kg, respectively) and also high concentrations of organic matter (OM), comparing to other Scandinavian and Arctic glaciers, reaching up to ~40% of total mass. The outstandingly high concentrations of 137Cs, 241Am, Pu isotopes, and 207Bi on the Blåisen Glacier are primarily related to bioaccumulation of radionuclides in organic-rich cryoconite and might be enhanced by additional transfers of contamination from the tundra by lemmings during their population peaks. The presumed influence of intense rainfall on radionuclide concentrations in the cryoconite was not confirmed.

Distribution of plutonium isotopes in soils between two nuclear test sites: Semipalatinsk and Lop Nor

Plutonium (Pu) has attracted attention as an environmental tracer due to its radiotoxicity and the possibility of sources linked with nuclear accidents in recent years. Plutonium isotopes (239,240Pu) were detected at trace levels in soils collected from the Xinjiang region located between the Semipalatinsk nuclear test site and China's Lop Nor nuclear test site. Little is known regarding the spatial variation of 239,240Pu in soils from this region. This study reports the use of Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS) methods to distinguish between Pu isotopes derived from global fallout and nuclear weapon tests. We found that the 239,240Pu activity concentrations ranged from 0.035 to 1.338 mBq/g; the 240Pu/239Pu atomic ratios were 0.157–0.223 with a weighted average of 0.180 ± 0.002, corresponding with the expected average global fallout ratio of 0.180 ± 0.014. This indicated that global fallout is the major source of Pu in the study region. The 239,240Pu inventories in these soils ranged from 23.67 to 222.7 Bq/m2, corresponding with those from other areas in China and other countries within the latitude range. Our Pu isotope data was supplemented with other published Pu data for soils collected in the vicinity of the Semipalatinsk nuclear test site and Lop Nor nuclear test site. Results indicate that 239,240Pu inventories and 240Pu/239Pu atomic ratios in soils exhibit large variations with distance from the Semipalatinsk nuclear test site. High deposition and accumulation of Pu, and low 240Pu/239Pu ratios were observed in close-in fallout and downwind regions of the Semipalatinsk nuclear test site and China's Lop Nor nuclear test site.

High efficiency laser resonance ionization of plutonium

Three-step resonance photoionization spectra of plutonium have been studied with Ti:Sapphire lasers for the development of efficient laser ionization schemes for ultra-trace analysis of Pu isotopes by resonance ionization mass spectrometry. We observed eighteen intermediate excited states of even parity in the energy range 35568–36701 {text {cm}}^{-1}, thirteen of them have not been previously documented, and a larger number of high-lying excited states and autoionizing states of odd-parity between 48238 and 49510 {text {cm}}^{-1}. Three-color, three-photon ionization schemes via six intermediate states were evaluated under similar ion source operating conditions. This led to a highly efficient three-step scheme with an overall ionization efficiency of 51.1 pm 1.3%, which is an order of magnitude improvement over the previously reported ionization efficiency for Pu.

Preliminary Study on Minor Actinide Incineration in RSG-GAS without Isotope Separation

Minor actinides (MA) resulted from nuclear power plants is often considered as nuisance in spent fuel management due to its considerably long half-life. One of available strategies to deal with MA is to incinerate it, in order to reduce its radioactivity. This paper presents a study on MA incineration in RSG-GAS research reactor. Unlike previous study, this work did not separate the MA into individual isotopes, but incinerated as a whole. ORIGEN2.1 code is employed to calculate MA incineration within RSG-GAS core. MA composition used in this study consists of Np, Am, and Cm isotopes. The Central Irradiation Position (CIP) of RSG-GAS is loaded by 6 kg of MA and irradiated for two years. The result shows that about 1 kg of MA were incinerated after two years of irradiation, or 18,87% of the initial concentration. However, the increase of Cm-242 isotope, along with newly-formed Pu isotopes, were found to be significantly increasing short-term radioactivity compared to un-irradiated MA. Thus, two years-worth of MA incineration cannot be considered as effective, and other strategies must be pursued.

Soil-soil solution distribution coefficients of global fallout 239Pu and 237Np in Japanese paddy soils

239Pu and 237Np are long-lived radionuclides that emit alpha rays, and once released into the environment, they are present there for a long period of time. Therefore,239Pu and 237Np are important radionuclides in the safety assessment related to geological disposal of radioactive waste because of the possibility of long-term exposure to humans. Mobilities of these radionuclides in the environment are of particular interest; therefore, in this study, we have made the first-time determination of the soil-soil solution distribution coefficient (Kd, L/kg) using global fallout 239Pu and 237Np in soil. The Kd values were determined by extracting these radionuclides from 23 soil samples using a laboratory batch method. The desorption Kd values of 239Pu were found to vary from 3.2 × 103 to 1.4 × 105 L/kg, and their geometric mean (GM) and arithmetic mean (AM) were 2.3 × 104 L/kg and 3.2 × 104 L/kg, respectively. The desorption Kd values of 237Np ranged from 8.9 × 102 to 2.1 × 104 L/kg, and their GM and AM were 4.1 × 103 L/kg and 6.4 × 103 L/kg, respectively. A comparison between the obtained Kd values of 239Pu and 237Np indicated that the former were about 6-fold higher than the latter in Japanese paddy field soils. Pearson's correlation analysis suggested that the main factors contributing to the sorption and desorption of Pu isotopes in Japanese paddy soils were related to the amounts of Fe and Mn oxides, while the sorption and desorption of 237Np in them would be controlled by an ion-exchange reaction, and/or complex-formation with organic matter, especially in Fluvisols.

Impact of pairing interactions on fission in the deformed mean-field plus standard pairing model

The role of pairing interactions on fission barriers and static fission paths in Th, U and Pu isotopes is investigated by using the deformed mean-field plus standard pairing model. It is found that pairing interaction plays different roles in different stages of the fission process. The first and second saddle point of the fission process are sensitive to the pairing interaction strength, while the ground-state and prescission points are mainly driven by nuclear deformation. It is also demonstrated that pairing interactions play a crucial role in the region of the inner and outer barriers. The barrier heights obtained by using the present model are found to reproduce the experimental data remarkably well and yield better results than those obtained by using the BCS approximation, thus indicating the importance of exact solutions of pairing interactions. Through numerical analysis, we provide possible microscopic pictures of spontaneous fission in the current pairing model.

Utilization of Military Grade Plutonium in Generation-IV Gas Cooled Fast Reactor

The operation of fast spectrum concepts like Gas cooled Fast Reactor (GFR) requires fuel with high enrichment of the fissile isotope 239Pu. In this work the utilization of Weapon Grade Plutonium (WGrPu) in GFR is investigated. For that, the transport code MCNPX is employed to design two models of the GFR2400 core one is heterogeneous and the other is homogeneous. The designed models are used to perform a neutronic analysis of the use of WGrPu as a fissile material instead of the reference Reactor Grade Plutonium (RGrPu) vector. The proposed WGrPu fuel has shown some improved neutronic and safety parameters compared to the reference RGrPu fuel.

Isotopic distributions of thermal-neutron-induced fission fragments of near-symmetric fission of Pu239,241 determined using calorimetric low-temperature detectors

Isotopic distributions were measured for the light fragment group in the transition region from asymmetric to symmetric fission for thermal neutron induced fission of $^{239}\mathrm{Pu}$ and $^{241}\mathrm{Pu}$ using the novel technology of calorimetric low temperature detectors in combination with the passive absorber method. Nuclear charge distributions were determined for 24 masses in the range $A=89$ to $A=112$ for $^{241}\mathrm{Pu}({n}_{\mathrm{th}},f)$ for the first time with the LOHENGRIN mass spectrometer. Moving from asymmetric to symmetric fission, known data were supplemented for masses from $A=110$ to $A=112$ for $^{241}\mathrm{Pu}({n}_{\mathrm{th}},f)$ and from $A=109$ to $A=113$ for $^{239}\mathrm{Pu}({n}_{\mathrm{th}},f)$. The isotopic yields were used to evaluate the charge polarization $\mathrm{\ensuremath{\Delta}}Z$ and the proton odd-even effect $\ensuremath{\delta}p$ with emphasis on the borderline between asymmetric and symmetric fission. This highlighted a virtual shell effect near $Z=44$ which mirrors the effect of the $Z=50$ shell in the complementary heavy fragment group of the two Pu isotopes $(Z=94)$ studied.

Agile fusion method for the determination of Pu isotopes in diverse sediments

Atmospheric nuclear testing has occurred worldwide resulting in trace amounts of plutonium (Pu) isotopes in soils and sediments across the globe. Soils and sediments can vary greatly in both physical and chemical properties within close geographic regions presenting a major challenge for sample preparation in the analysis of fallout radionuclides. It is vital to have a rapid, agile method for the complete digestion of samples containing refractory Pu particles to address this challenge. A radioanalytical procedure for the analysis of Pu isotopes in soils/sediments has been developed improving sample preparation using fusion. This is done by eliminating the need for pre-dissolution combustion to remove organic material and providing greater application to a diverse range of samples including those of metal-bearing mineralogy. The integration of borate and peroxide flux materials creates a sample dissolution procedure that is greater than the sum of its parts. This method is applicable to the analysis of 239/240Pu in soil/sediment samples with a sample mass of 3 g, ranging from 0.05 to 5000 mBq/g achieving 242Pu tracer recoveries between 50 and 94%, with a trace-level detection limit of 0.04 mBq/g and measurement uncertainties down to 19%; adjustable to measurement priorities with variation in count time, background counts, chemical recovery and total activity of the sample. This sample preparation technique can be utilized with complementary analysis of alpha spectrometry or ICP-MS. Achieving these parameters provides a highly adaptable standard method for 239/240Pu in soil/sediment analysis applicable to samples from radioecological research at trace environmental levels to emergency response scenarios with 48-h turn-around producing highly repeatable, succinct and high-quality analysis.

Explore the possible advantages of using thorium-based fuel in a pressurized water reactor (PWR) Part 1: Neutronic analysis

This study discusses the effect of using 232Th instead of 238U on the neutronic characteristics and the main operating parameters of the pressurized water reactor (PWR). MCNPX version 2.7 was used to compare the neutronic characteristics of UO2 with (Th, 235U)O2 and (Th, 233U) O2. Firstly, the infinity multiplication factor (Kinf), thermal neutron flux, and power distribution have been studied for the investigated fuel types. Secondly, the effect of Gd2O3 and Er2O3 on the Kinf and on the radial thermal neutron flux and thermal power has been investigated to distinguish which of them is more suitable than the other in reactivity management. Thirdly, to illustrate the effectiveness of 232Th in decreasing the inventory of both the actinides and non-actinides, the concentration of plutonium (Pu) isotopes and minor actinides (MAs) has been simulated with the fuel burnup. Besides, due to their large thermal neutron absorption cross-section, the concentrations of 135Xe, 149Sm, and 151Sm with the fuel burnup have been investigated. Finally, the main safety parameters such as the reactivity worth of the control rods (ρCR), the effective delayed neutron fraction βeff, and the Doppler reactivity coefficient (DRC) were calculated to determine to which extent these fuel types achieve the acceptable limits.

Fission fragment decay simulations with the CGMF code

The CGMF code implements the Hauser-Feshbach statistical nuclear reaction model to follow the de-excitation of fission fragments by successive emissions of prompt neutrons and γ rays. The Monte Carlo technique is used to facilitate the analysis of complex distributions and correlations among the prompt fission observables. Starting from initial configurations for the fission fragments in mass, charge, kinetic energy, excitation energy, spin, and parity, Y(A,Z,KE,U,J,π), CGMF samples neutron and γ-ray probability distributions at each stage of the decay process, conserving energy, spin and parity. Nuclear structure and reaction input data from the RIPL3 library are used to describe fission fragment properties and decay probabilities. Characteristics of prompt fission neutrons, prompt fission γ rays, and independent fission yields can be studied consistently. Correlations in energy, angle and multiplicity among the emitted neutrons and γ rays can be easily analyzed as a function of the emitting fragments. In its current version, CGMF is limited to certain spontaneous fission reactions on Pu and Cf isotopes, as well as neutron-induced fission reactions up to 20 MeV on U, Np, and Pu isotopes. Program summaryProgram Title:CGMF 1.1CPC Library link to program files:https://doi.org/10.17632/jrtt73npzw.1Licensing provisions: BSD-3 clauseProgramming language: C++Nature of problem: Modeling of fission fragment decaySolution method: Monte Carlo implementation of the Hauser-Feshbach statistical theory of nuclear reactions to describe the de-excitation of fission fragments on an event-by-event basis.Additional comments including restrictions and unusual features: spontaneous fission reactions for 238,240,242,244Pu and 252,254Cf; neutron-induced fission reactions from thermal up to 20 MeV for n+233,234,235,238U, n+237Np, and n+239,241Pu. Binary fission only (no ternary fission).

Review and Evaluation of the Spontaneous Fission Half-lives of 238Pu, 240Pu, and 242Pu and the Corresponding Specific Fission Rates

A widely applied technical measure of nuclear safeguards and nonproliferation for the nondestructive verification and mass-assay of items containing separated plutonium is passive neutron multiplicity counting. The primary source of time correlated passive neutrons is the spontaneous fission of Pu, where the 240Pu is usually the dominant isotope with 238Pu and 242Pu also contributing to a degree depending on the grade or burnup of the material. Consequently, knowledge of the 240Pu spontaneous fission rate, expressed as fission per gram per second, and the associated uncertainty is key in interpreting measurement data absolutely. The 240Pu spontaneous fission rate derives (and vice versa) from the 240Pu spontaneous fission half-life. In this work we review and reevaluate the available experimental data on the spontaneous fission (SF) half-life of the Pu isotopes 238Pu, 240Pu and 242Pu. The SF half-lives are used to compute the corresponding specific SF rates which are the traditional nuclear data parameters needed for analytical applications, especially the nondestructive assay of plutonium for safety, security and safeguards.From 7 measurements we recommend a SF half-life of (4.745 ± 0.083) × 1010y for 238Pu corresponding to a specific SF rate of (1171 ± 20) fis ⋅ s-1 ⋅ g-1.There are 16 absolute experimental determinations of 240Pu half-life. Based on this evaluation, we find that the weighted mean of the 16 half-life determinations is (1.1608 ± 0.0091) × 1011y corresponding to a specific SF rate of (474.7 ± 3.7) fis ⋅ s−1 ⋅ g−1, where the relative uncertainty of about 0.78% is the external standard error.From 8 measurements we recommend a SF half-life of (6.766 ± 0.037) × 1010y for 242Pu corresponding to a specific SF rate of (807.7 ± 4.4) fis ⋅ s−1 ⋅ g−1. Finally, we conclude that there is a need for more experiments on all three plutonium nuclides using new techniques that have emerged in recent years.

A simple acid digestion using HCl–HNO3−NH4HF2 for rapid SF-ICP-MS determination of 237Np and Pu isotopes in steel and concrete samples

A simple acid digestion using HCl–HNO3−NH4HF2 for rapid SF-ICP-MS determination of 237Np and Pu isotopes in steel and concrete samples

Contribution of close-in fallout from the French atmospheric tests in inventories of 137Cs, 241Am and plutonium (238, 239, 240) in Gambier Islands (French Polynesia) – Signatures of stratospheric fallout in the Southern Hemisphere

The inventories of 137Cs (503 ± 34 Bq.m−2), 241Am (11.3 ± 1.2 Bq.m−2), 241Pu (33.7 ± 3.4 Bq.m−2), 238Pu (6.82 ± 0.87 Bq.m−2) and 239+240Pu (113.0 ± 5.9 Bq.m−2), sum of 239Pu (100 ± 11 Bq.m−2) and 240Pu (14.5 ± 1.7 Bq.m−2), in the Gambier archipelago (23°S) of the French Polynesia, are well higher the global fallout at this latitude, in unequal proportions for the different radionuclides. (240Pu/239Pu)AR (AR: atomic ratio) of 0.0394 ± 0.0062, and (241Pu/239Pu)AR of (2.03 ± 0.39)10−4, confirm that the overwhelmingly dominant source of these radionuclides comes from local fallout during the 1970s of the French atmospheric tests of Moruroa and Fangataufa located nearly 400 km from Gambier. The signatures of the local fallout were deduced from the excess of its inventory in 137Cs and from the mixing lines established from the signatures of the global fallout, some of the test sites and the isotopic ratios measured in Gambier. Signatures obtained are 2.0 ± 0.4 for 137Cs/239+240Pu, 0.045 ± 0.008 for 238Pu/239+240Pu, 0.031 ± 0.009 for 241Am/239+240Pu, 0.092 ± 0.027 for 241Pu/239+240Pu, 0.0163 ± 0.0049 for (240Pu/239Pu)AR, (0.78 ± 0.23)10−4 for (241Pu/239Pu)AR. The concordance of the mixing lines of the [(240Pu/239Pu)AR, (241Pu/239Pu)AR] and the linear regression of these ratios measured in the stratosphere (40°S) during the 1970s, indicates that the signatures of the close-in deposition are also those of the stratospheric injections of the French tests. The signatures of stratospheric fallout in the Southern Hemisphere were evaluated by considering that the fission energy of these injections represents 11% and that of the Northern Hemisphere represents 89% and that the isotopic ratios of stratospheric injections remained the same over the period 1970–1974. The activity ratios deducted are 21.9 ± 0.1 in 137Cs/239+240Pu, 0.11 ± 0.05 in 238Pu/239+240Pu, 1.03 ± 0.12 in 241Pu/239+240Pu and 0.35 ± 0.04 in 241Am/239+240Pu. The associated atom ratios are 0.157 ± 0.011 for (240Pu/239Pu)AR and (8.33 ± 0.48)10−4 for (241Pu/239Pu)AR. These signatures appear to be consistent with the results of the inventories at Hiva Oa, located more than 1,000 km north of both French test sites, and with those found in the Australian continent, in regions not impacted by UK-test debris. The proportions of close-in tropospheric fallout from the French tests are about 90% in Gambier. They represent a proportion in the inventories of 40% for the 137Cs, 60% for 241Am and in the range between 80 and 90% for Pu isotopes.

Temporal variability of Pu signatures in a 210Pb-dated Sphagnum peat profile from the Northern Ural, Russian Federation

The peat archives are one of the stratigraphic records revealing clearly physical, chemical and biological signals of human influence on the Earth System since the 1950s, at least. The presented study was aimed mainly to identify the level and origin of anthropogenic radionuclides such as 238, 239, 240Pu in a 210Pb-dated peat profile derived from the Northern Ural, Russian Federation. As stated, the vertical variability of 240Pu/239Pu isotopic compositions reflects the nuclear weapons testing history with the maximum in the 1960s and small regional impact most likely of high-yielded tests in the 1950s as well as Chinese detonations in the 1970s. Peat accumulations rates were similar to those obtained in adjacent areas, whereas 210Pb flux slightly exceeded the reference level established for adequate latitude belt.

A rapid, automated system for the separation, preconcentration and measurement of 90Sr, and U, Am and Pu isotopes

An online separation and preconcentration method, using an automated flow injection setup and solid phase extraction followed by ICP-MS/MS, was developed for the analysis of 90Sr, and U, Am and Pu isotopes in various liquid sample matrices. The radionuclide analytes were separated from interferences and complex matrices using DGA-branched resin and Sr resin, then specific gases were used in the reaction/collision cell in the ICP-MS/MS to measure the different analytes. The system requires smaller sample volumes (10 mL), less sample preparation and shorter processing time (46 min per sample) compared to traditional radiometric and other MS techniques. Based on a 10 mL sample, the limits of detection were 1.48 pg L−1 (8257 mBq L−1) for 90Sr, 1.75 pg L−1 (0.40 mBq L−1) for 234U, 0.65 pg L−1 (77.65 mBq L−1) for 241Am, and 0.56 pg L−1 (1.25 mBq L−1) for 239Pu when all target analytes were measured in one analysis. The analytical figures of merit were evaluated for a range of sample matrices including lake water, seawater and urine and were comparable to those reported in the literature. This online system thus provides a novel, fully automated analytical tool with faster analysis time, smaller sample requirements, minimum sample preparation, low detection limits and the flexibility to handle single and multiple measurements of various radionuclides.

Distinctive distribution and migration of global fallout plutonium isotopes in an alpine lake and its implications for sediment dating

This work investigated plutonium (Pu) isotopes in sediment cores collected from an alpine lake (Lake Heinongpo with 3779 m above sea level) in Southwestern China. 240Pu/239Pu atom ratios in all sediment samples showed the typical global fallout values of ∼0.18 without any influences from other Pu contaminant sources. 239+240Pu activities with surface and subsurface maximums followed by exponential decline with sediment depth were respectively observed in the two sediment cores. The distinctive depth distributions of 239,240Pu in the lake sediments was attributed to the very slow sediment deposition rate due to the lack of terrestrial sediment input, while the alpine snowmelt input was the primary source of Pu in the lake sediments in addition to the direct atmospheric deposition. The total Pu inventory was estimated to be 56.3 ± 1.4 and 63.9 ± 0.8 Bq/m2 respectively in the two sediment cores. The generally higher Pu inventory in the Lake Heinongpo compared with other reported lakes in similar latitude should be mainly attributed to their different Pu input passages. The advection-diffusion equation was further applied to evaluate the downward migration of Pu isotopes in the sediment cores and predict the future evolution of Pu distribution in the sediment cores. The fitted results indicated that the diffusion effect controlled the downward migration of Pu in the sediments, but this diffusive migration will not prevent the peak of global fallout Pu in undisturbed sediment cores from being a valuable time marker for sediment dating.

Rapid analysis of 237Np and Pu isotopes in small volume urine by SF-ICP-MS and ICP-MS/MS

Internal contamination with alpha-particle emitting actinides, such as 237Np, 239Pu, 240Pu, is likely to bring a large amount of dose to the tissues of persons even if the intake amount is small. To provide timely information for prompt decision-making in radiation emergency therapy, we developed a simple and rapid method for urinary bioassay to determine ultra-trace 237Np and Pu isotopes using SF-ICP-MS and ICP-MS/MS. To avoid polyatomic interferences and tailing effects from U, 237Np and Pu isotopes were collected after removing U effectively using a simple single chromatographic column packed with 2 mL AG MP-1M anion exchange resin, exhibiting a high decontamination factor of 108 for 238U. The overall chemical fractionation between 237Np and 242Pu for the whole analytical procedure was 0.974 ± 0.064 (k = 2), allowing us to measure 237Np and Pu isotopes using 242Pu as a yield tracer with yields of 76 ± 5%. Using ICP-MS/MS with low background provided the method detection limits for 237Np, 239Pu, 240Pu, and 241Pu of 0.025, 0.025, 0.015, and 0.020 fg mL−1, respectively, for 20 mL of urine sample. Those were comparable to detection limits of SF-ICP-MS with high sensitivity. Subsequently, three urine reference materials with Pu spike, provided by the Association for the PROmotion of Quality COntrol in RADiotoxicological Analysis (PROCORAD), France, were analyzed by the developed method and the conventional alpha spectrometry technique for validation. Finally, the developed method was successfully employed to measure the contamination level of 237Np, 239Pu, 240Pu, and 241Pu in urine samples collected during decorporation therapy using DTPA, after a Pu inhalation exposure accident in Japan. The high throughput (9 h for 12 samples), simplicity, low cost, and high sensitivity of the method will allow greater numbers of related laboratories to be involved in screening activities for unexpected actinide exposure, such as in the case of a large scale radiological disaster.

Rapid method for sequential determination of Pu and Am in soil and sediment samples by sector-field inductively coupled plasma mass spectrometry

New method was developed to analyze Pu and Am sequentially for soil and sediment by inductively coupled plasma mass spectrometry (ICPMS). The developed method uses conc. HNO3 to leach Pu and Am, Fe(OH)3 coprecipitation to remove alkali and alkaline metals, extraction chromatographic separation using UTEVA, DGA and TEVA resins to remove interfering elements (IEs) and separate Pu and Am from each other, and sector field-ICPMS to measure Pu and Am. The analysis of four standard reference materials showed that both Pu isotopes and 241Am were accurately determined by this method, as a result of its excellent decontamination ability of IEs. Especially the high decontamination factor of Pu [DF(Pu), 4.2 × 102] in Am fraction and high DF(Am) (7.0 × 103) in Pu fraction sufficiently eliminated the cross interference between 241Pu and 241Am in ICPMS measurement. In addition, stable and high chemical recoveries were achieved for Pu (71–91%) and Am (70–88%). The low LODs of Pu isotopes, short analytical time (14 h) and high DFs of IEs allows this method to sequentially analyze Pu and Am, for both global fallout and nuclear accident sourced samples.