Concentration of239, 240Pu in human bone

Some results of the plutonium determination for bone ash samples collected in Japan are presented. Mean^239,240Pu concentration in the adult vertebra was 0.53 pCi/kg of ash during the period 1978 through 1983. The data are roughly in coincidence with estimated plutonium concentrations in the trabecular bone from reported air plutonium concentrations using the ICRP model and metabolic data, and weight of bone in Reference Japanese Man.     

Use of combined alpha-spectrometry and fission track analysis for the determination of240Pu/239Pu ratios in human tissue

Plutonium and other actinides were determined in human autopsy tissues of occupationally exposed workers who were registrants of the United States Transuranium and Uranium Registries (USTUR). In this study, Pu was purified and isolated from Am, U and Th, after drying and wet-ashing of the tissues, and the addition of²³⁸Pu as a radiotracer. After electrodeposition onto vanadium planchets the^239+240Pu activity was determined by alpha-spectrometry. A fission track method was developed to determine²³⁹Pu in the presence of²³⁸Pu and²⁴⁰Pu, using Lexan^TM polycarbonate detectors. Combining the two techniques allowed the determination of the²⁴⁰Pu/²³⁹Pu activity and atom ratios. Data from selected USTUR cases are presented.     

Determination of 238Pu, 239+240Pu and 241Am in air filters

The aim of this work is to present the method for sequential plutonium and americium activity determination in air filters using chromatographic radionuclide separation and alpha spectrometry measurement. The developed method may be employed for the purposes of workplace monitoring and as an indicator of the need of introducing the individual monitoring as well as a useful complementation of individual monitoring. Basic parameters describing the developed method such as values of chemical recoveries and minimum detectable activities for plutonium and americium isotopes have been determined. Applied counting efficiency was obtained using Monte Carlo calculation method.

     

A comparison of239+240Pu post-mortem measurements with estimates based on current ICRP models

Measurements of^239+240Pu in human tissues, from nuclear weapons testing, provide an invaluable source of data for verifying the uptake and distribution of radionuclides in the body. Measured concentrations of^239+240Pu in lung, tracheobronchial lymph nodes, liver and skeleton have been compared with concentrations calculated using estimated plutonium intakes, the ICRP Publication 66 Respiratory Tract Model and the ICRP Publication 67 biokinetic model for plutonium. Measurement data tend to fall between the concentrations estimated on the basis of Type M and Type S absorption parameters. This indicates that the models represent the movement of plutonium through the body reasonably well.     

Radioanalytical approach to determine 238Pu, 239+240Pu, 241Pu and 241Am in soils

The simultaneous determination of multiple actinide isotopes in samples where total quantity is limited can sometimes present a unique challenge for radioanalytical chemists. In this study, re-determination of ²³⁸Pu, ^239+240Pu, and ²⁴¹Am for soils collected and analyzed approximately three decades ago was the goal, along with direct determination of ²⁴¹Pu. The soils had been collected in the early 1970’s from a shallow land burial site for radioactive wastes called the Subsurface Disposal Area (SDA) at the Idaho National Lab (INL), analyzed for ²³⁸Pu, ^239+240Pu, and ²⁴¹Am, and any remaining soils after analysis had been archived and stored. We designed an approach to reanalyze the ²³⁸Pu, ^239+240Pu, and ²⁴¹Am and determine for the first time ²⁴¹Pu using a combination of traditional and new radioanalytical methodologies. The methods used are described, along with estimates of the limits of detection for gamma-and alpha-spectrometry, and liquid scintillation counting. Comparison of our results to the earlier work documents the ingrowth of ²⁴¹Am from ²⁴¹Pu, and demonstrates that the total amount of ²⁴¹Am activity in these soil samples is greater than would be expected due to ingrowth from ²⁴¹Pu decay.     

240Pu/239Pu atom ratios in the bottom sediments of the NW Pacific Ocean

^239+240Pu concentrations and ²⁴⁰Pu/²³⁹Pu atom ratios in bottom sediments of the Yellow Sea, Korea Strait, East Sea (Sea of Japan), Sea of Okhotsk, and Northwest Pacific Ocean were determined. In coastal sediments near the Korean Peninsula, ^239+240Pu concentrations varied from 0.02 to 1.72 Bq^.kg^-1, and their ²⁴⁰Pu/²³⁹Pu atom ratios from 0.15 to 0.24, with an average of 0.20±0.03. ²⁴⁰Pu/²³⁹Pu atom ratios of bottom sediments in the deep NW Pacific Ocean and its marginal seas (East, Okhotsk seas) were in the range of 0.15-0.23. A little elevated ²⁴⁰Pu/²³⁹Pu atom ratios in the bottom layer sediment may be due to Pu released into the environment during the pre-moratorium period, having high ²⁴⁰Pu/²³⁹Pu atom ratios and low ²³⁸Pu/^239+240Pu activity ratios.     

Determination of femtogram quantities of 239Pu and 240Pu in bioassay samples by thermal ionization mass spectrometry

Summary A thermal ionization mass spectrometry (TIMS) method is described for the determination of ultra-trace levels of plutonium isotopes in human urine samples. The method has been validated through the analysis of artificial urine samples spiked with known amounts of ²³⁹Pu ranging from 2.5 fg to 50 fg (6-115mBq). A slight positive bias of 1.7%-2.7% was determined, with a relative precision of 2.2% at 50 fg, increasing to 2.7% for 5-25 fg ²³⁹Pu. The detection limit of the method was 0.53 fg (1.2mBq) ²³⁹Pu, and the instrumental detection limit was at least 0.1 fg. The determination of the isotopic signature of the sample with ²³⁹Pu, ²⁴⁰Pu, and ²⁴¹Pu amounts of several femtograms is possible, and was demonstrated with the determination of the 240 to 239 ratio in an inter-laboratory sample comparison. The method is relatively free from interferences, 95% of sample preparations were acceptable both in terms of chemical recovery and lack of isobaric interference. The isotopic abundance of the ²⁴²Pu SRM 4334E of the National Institute of Standards and Technology (NIST) was also determined by TIMS and was found to be 99.99967 atom% ²⁴²Pu.     

The methods for239+240Pu analysis and their application to human tissues and food samples

The paper describes the recent plutonium measurements on tissues taken at human autopsy on foodstuffs collected in northern Japan. Estimates of plutonium concentrations are made using the ICRP 30 metabolic model and is compared with the results of our measurements.     

Simultaneous analysis of 137Cs, 90Sr, 238Pu and 239+240Pu in Brazilian seawater

Methodologies for simultaneous analysis of ¹³⁷Cs, ⁹⁰Sr, ²³⁸Pu and ^239+240Pu were developed and applied to seawater samples. ¹³⁷Cs levels in Brazilian coastal seawater ranged from 0.12 to 4.7 Bq·m^-3, for ⁹⁰Sr from 2.0 to 8.6 Bq·m^-3, for ^239+240Pu from 0.8 to 4.5 mBq·m^-3 and for ²³⁸Pu it was of 1.9 mBq·m^-3. The artificial radioactivity levels in Brazilian seawater are typical values due to fallout deposition.     

Measurement of240Pu/239Pu ratio by fission track method and inductively coupled plasma mass spectrometry

Fission track /FT/ method and inductively coupled plasma mass spectrometry /ICP-MS/, that is a new analytical technique for the analysis of trace element, were used for the measurement of²⁴⁰Pu/²³⁹Pu ratios in environmental samples. The results obtained by both methods are in agreement within the relative deviation of 9–13%. The precision in ICP-MS was found to be better than in it the FT-method. These methods are applicable to measure the Pu isotopes ratio at low concentration levels in environmental samples.     

239+240Pu concentrations of sediments and seawater in the coastal sea of Korea

Summary The ^239+240Pu content of the marine sediments and seawater of the costal sea of Korea was measured. In marine sediments the ^239+240Pu concentrations were in the range of 0.11-1.91 Bq/kg dry weight and in the coastal sea of Korea the ratio of ^239+240Pu/¹³⁷Cs was 0.27. The correlations between ^239+240Pu and ¹³⁷Cs concentrations and the content of organic matter (C, O, H, N, S) as well as the grain size of marine sediment were investigated by regression analysis. The distribution coefficient of ^239+240Pu was 1.22^. 10⁵. The ^239+240Pu concentration in seawater increased with seawater depth. However, the ¹³⁷Cs concentration in seawater did not change considerably with depth.     

Vertical profiles of 239+240Pu in seawater from the East China Sea

Seawater samples were collected from the East China Sea continental shelf and analyzed for ^239+240Pu activities. The vertical profiles of ^239+240Pu had a similarity for all three stations in the East China Sea. ^239+240Pu concentrations were low in the surface layer (3-4 mBq/m³) and increased gradually with depth to become high in the near-bottom layer (7-10 mBq/m³). ^239+240Pu concentrations in seawater and the concentrations of suspended particles showed almost the same vertical profiles in the East China Sea continental shelf. The maximum value of ^239+240Pu found in the near-bottom layer may be due to the contribution of Pu-rich suspended particles.     

90Sr and239+240Pu238Pu241Am in some samples of mushrooms and forest soil from Poland

Strontium-90, plutonium and americium activity concentrations in a few samples of forest soils, some species of mushrooms and fern leaves have been determined. These results are compared with cesium activity concentrations in the same materials obtained in a previous work. Radiochemical procedures are described. The origin of the contamination (Chernobyl accident or nuclear test explosion release) is discussed. The⁹⁰Sr activity concentration ranges from 0.6 Bq/kg (mushroom samples) to 48.4 Bq/kg (fern leaves). For^239+240Pu, it ranges from not detected above background (mushrooms, fern) to 10.8 Bq/kg (humus layer of forest soil). The maximum concentration of²⁴¹Am is found to be 2.4 Bq/kg (humus sample) and for²³⁸Pu it is 0.85 Bq/kg (also in the humus sample).     

A new internal conversion electron spectrometer and its application to determine the240Pu to239Pu isotope ratio

An internal conversion electron spectrometer with high energy resolution has been constructed by using a windowless Si(Li) detector. After its characteristics were examined fundamentally, it was applied to determine the²⁴⁰Pu to²³⁹Pu isotope ratio. As a result, the energy resolution realized was demonstrated to be satisfactory.     

Multi-isotopic determination of plutonium (239Pu, 240Pu, 241Pu and 242Pu) in marine sediments using sector-field inductively coupled plasma mass spectrometry

Among the transuranic elements present in the environment, plutonium isotopes are mainly attached to particles, and therefore they present a great interest for the study and modelling of particle transport in the marine environment. Except in the close vicinity of industrial sources, plutonium concentration in marine sediments is very low (from 10⁻⁴ ng kg⁻¹ for ²⁴¹Pu to 10 ng kg⁻¹ for ²³⁹Pu), and therefore the measurement of ²³⁸Pu, ²³⁹Pu, ²⁴⁰Pu, ²⁴¹Pu and ²⁴²Pu in sediments at such concentration level requires the use of very sensitive techniques. Moreover, sediment matrix contains huge amounts of mineral species, uranium and organic substances that must be removed before the determination of plutonium isotopes. Hence, an efficient sample preparation step is necessary prior to analysis. Within this work, a chemical procedure for the extraction, purification and pre-concentration of plutonium from marine sediments prior to sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS) analysis has been optimized. The analytical method developed yields a pre-concentrated solution of plutonium from which ²³⁸U and ²⁴¹Am have been removed, and which is suitable for the direct and simultaneous measurement of ²³⁹Pu, ²⁴⁰Pu, ²⁴¹Pu and ²⁴²Pu by SF-ICP-MS.     

Simultaneous liquid scintillation determination of239Pu and241Am in tissue

A liquid scintillation counting method for the simultaneous determination of Pu and Am, with a two-phase cocktail, has been applied to the analysis of a tissue sample from an accidental exposure incident. The sample contained²³⁹Pu,²⁴¹Pu, and²⁴¹Am. In addition to analysis by two liquid scintillation counting techniques, analysis of the sample was performed by -spectroscopy and ZnS scintillation techniques, and the results were compared. The presence of²⁴¹Pu interfered with the liquid scintillation determination of²⁴¹Am when the two-phase cocktail was used, but the results were in agreement sufficient to be useful in determining what course of treatment, if any, might be necessary for the patient.     

239+240Pu and 137Cs in Sediments from Tokyo Bay: Distribution and Inventory

Four sediment cores were collected from Tokyo Bay and analyzed for their ^239+240Pu and ¹³⁷Cs concentrations. Shallow nearshore sediments from Tokyo Bay have ^239+240Pu inventories which average 214±14 MBq/km². They are five times greater than the supply expected from the atmospheric global fallout at the same latitude of 42 MBq/km². The measured mean ¹³⁷Cs inventory of 433±93 MBq/km² is approximately one fifth the value expected from global fallout. Furthermore, the ^239+240Pu/¹³⁷Cs activity ratios, with a mean ratio of 0.50±0.14, are significantly greater than the ratio expected from the global fallout of 0.021. Excess ^239+240Pu inventories can be considered to have been introduced into Tokyo Bay as weathering products by soil erosion, transported via rivers and winds, and to be much more efficiently scavenged from seawater by particles resuspended at the sediment-water interface.     

激光剥蚀-多接收电感耦合等离子体质谱法 测定含钚颗粒物中240 Pu/239 Pu比值

为高精度、准确地获取含钚颗粒物中具有核保障监督意义和核取证价值的钚同位素比值,建立了激光剥蚀-多接收电感耦合等离子体质谱(LA-MC-ICP-MS)测定含钚颗粒物中240 Pu/239 Pu的分析方法.采用检漏、安装排风罩和擦拭剥蚀池内壁等方式有效降低激光剥蚀产物沾污实验室和危及人身安全的潜在风险.联用扫描电迁移率粒径谱仪(SMPS)与激光剥蚀-多接收器等离子体质谱(LA-MC-ICP-MS)研究了激光剥蚀玻璃基体标样产生气溶胶的分布特性,结果表明,剥蚀产物的主要粒径是40~500 nm,应尽量采用水平管道连接激光剥蚀进样系统与MC-ICP-MS,含钚颗粒物分析后剥蚀池持续吹扫时间应大于15 min.采用外标归一化法离线校正质量分馏效应和离子计数器检测效率,建立了含钚颗粒物中240 Pu/239 Pu的LA-MC-ICP-MS分析方法,固定束斑直径30μm、脉冲重复率5 Hz、剥蚀时间5 s,调节能量密度使含钚颗粒物模拟样品中239 Pu的信号强度分别达2×104 cps和2×105 cps,本方法对240 Pu/239 Pu测量的相对实验标准不确定度小于1.4%(n=6),测量结果与参考值的相对偏差小于4.7%,仪器调试时间和单个样品测量时间分别为9.0和0.5 h.含钚颗粒物模拟样品分析结果表明,本方法精度高、结果准确、分析速度快,可满足核保障监督、禁产核查和核取证中含钚颗粒物直接分析的需求.     

Large volume preconcentration and purification for determining the240Pu/<Superscript>239</Superscript>Pu isotopic ratio and <Superscript>238</Superscript>Pu/<Superscript>239+240</Superscript>Pu alpha-activity ratio in seawater

Summary The present paper describes a new analytical method for determining the ²⁴⁰Pu/²³⁹Pu isotopic ratio and ²³⁸Pu/^239+240Pu α -activity ratio in seawater, both of which are important parameters for determining Pu sources in the ocean. Plutonium isotopes were preconcentrated from a large volume of seawater (4700-10800 liter) by solid phase extraction using MnO₂-impregnated fibers and eluted into 3M HCl. After the elution, the Pu species of all oxidation states were converted to Pu(IV) using NaNO₂, purified by solvent extraction using thenoyltrifluoroacetone (TTA)-benzene, and concentrated in 5 ml of 0.2M HNO₂. The ²⁴⁰Pu/²³⁹Pu and ²³⁸Pu/^239+240Pu ratios in the 5-ml final solution were determined by inductively coupled plasma-mass spectrometry (ICP-MS) and α-spectrometry, respectively. A pg level of Pu, which was a sufficiently large amount for the determination, was obtained by the solid phase extraction. Through the redox conversion and solvent extraction, the Pu species, such as Pu(III), Pu(IV) and Pu(VI), were collected at a high recovery of 96±2% (n=3) despite the presence of large amounts of Mn, and interfering ²³⁸U (3.3 μg^. l^-1in seawater) was effectively removed with a decontamination factor of 1.7·10⁷. The accuracy of the method for the ²⁴⁰Pu/²³⁹Pu ratio was verified using reference materials of seawater and a terrestrial soil sample. The present technique was applied to the determination of the ²⁴⁰Pu/²³⁹Pu and ²³⁸Pu/^239+240Pu ratios in coastal and oceanic water.     

Determination of239, 240Pu in environmental samples from surroundings of the atomic power station Jaslovske Bohunice

The development of a rapid and reproducible method for the separation of plutonium from soil samples is described. Tetravalent plutonium is extracted from 8M HNO₃ into 30% Aliquat-336/toluene mixture. Uranium and thorium are removed with nitric and hydrochloric acid washes. Plutonium is backextracted with HCl–H₂C₂O₄ and HCl–HF solutions. Plutonium is coprecipitated with NdF₃ and filtrated onto a 0.1–0.2 m membrane filter to prepare a source for -spectrometry. The chemical yields of separation are about 50–60%.