共查询到20条相似文献,搜索用时 31 毫秒
1.
K. Norisuye K. Okamura Y. Sohrin H. Hasegawa T. Nakanishi 《Journal of Radioanalytical and Nuclear Chemistry》2005,267(1):183-193
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. 相似文献
2.
S. F. Love R. H. Filby S. E. Glover R. L. Kathren D. B. Stuit 《Journal of Radioanalytical and Nuclear Chemistry》1998,234(1-2):189-193
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 the239+240Pu activity was determined by alpha-spectrometry. A fission track method was developed to determine239Pu in the presence of238Pu and240Pu, using LexanTM polycarbonate detectors. Combining the two techniques allowed the determination of the240Pu/239Pu activity and atom ratios. Data from selected USTUR cases are presented. 相似文献
3.
Terry Hamilton Doug Dasher Tom Brown Roger Martinelli Alfredo Marchetti Steven Kehl 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(2):477-482
Plutonium-239 (239Pu) and plutonium-240 (240Pu) activity concentrations and 240Pu/239Pu atom ratios are reported for Brown Algae (Fucus distichus) collected from the littoral zone of Amchitka Island (Alaska), and at a control site at Unalaska, Alaska. The average 240Pu/239Pu atom ratio observed in dried F. distichus collected from Amchitka Island was 0.227 ± 0.007 (N = 5) and compares with the expected 240Pu/239Pu atom ratio in integrated worldwide fallout deposition in the Northern Hemisphere of 0.1805 ± 0.0057. In the absence of
any evidence of a local source of plutonium containing an elevated 240Pu/239Pu isotopic signature, the characteristically high 240Pu/239Pu content of F. distichus supports the view of the existence of a discernible, basin-wide non-fallout source of plutonium entering the subarctic Pacific. 相似文献
4.
Various plutonium compounds are handled in nuclear facilities of BARC. Hence, there is a possibility of occupational workers
getting exposed to Pu. In vitro bioassay monitoring in which Pu is separated by chemical procedures from excreta samples and
estimated by alpha-spectrometry, is the method of choice for the evaluation of internal dose to the occupational workers handling
Pu. However, this method requires a suitable Pu tracer for reducing the uncertainties due to chemical yield in the separation,
electro-deposition and counting efficiency. 242Pu is commonly used as a tracer but due to its non-availability, efforts were made earlier to indigenously synthesis 236Pu by proton irradiation of 237Np in BARC-TIFR pelletron facility. The present study, reports the feasibility of using 236Pu as a radiochemical yield monitor (tracer) in bioassay samples. 相似文献
5.
Studies of plutonium in the environment have focused on the α-emitting isotopes 238Pu, 239Pu and 240Pu, often overlooking the β-emitting isotope 241Pu because of its relatively short half-life (14.4 years). Here, we summarize sources of 241Pu and discuss its distribution and behavior in the environment. In the short term, 241Pu, the largest contributor to the total plutonium radioactivity whereas in the long term its decay products, 241Am and 237Np, are the major contributors as some 46% of current total 241Am is attributable to 241Pu decay. In this context, understanding the fate and transport of 241Pu is crucial to assessing long-term radiological dose. 相似文献
6.
D. W. Efurd R. E. Steiner F. R. Roensch S. E. Glover J. A. Musgrave 《Journal of Radioanalytical and Nuclear Chemistry》2005,263(2):387-391
Summary Extensive soil and sediment sampling was conducted along the Colorado Front Range and the plains east of the Front Range at locations believed to only be exposed to global fallout. The average 240Pu/239Pu atom ratio in the samples collected in Colorado was determined to be 0.165±0.008. A limited number of samples were collected at various locations in the Arctic at approximately 70° N latitude. Analyses of these samples predict that the 240Pu/239Pu atom ratio in environmental samples collected at 70° N latitude at locations only containing fallout is 0.183±0.009. These results provide data that help to precisely define the 240Pu/239Pu atom ratios representative of global fallout at the two locations studied. 相似文献
7.
E. Hrnecek R. Jakopič A. Wallner P. Steier 《Journal of Radioanalytical and Nuclear Chemistry》2008,276(3):789-793
A combination of alpha-spectrometry, liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS) was used
for the determination of plutonium isotopes. 238Pu and 239+240Pu were measured by alpha-spectrometry after separation of Pu by anion-exchange using 236Pu tracer as recovery monitor. After alpha-measurement, one part of the sample was dissolved for determining 241Pu by LSC. Another part was used for the measurement of the 240Pu/239Pu atom ratio by AMS at VERA. Thus, it was possible to obtain complete information on the Pu isotopic composition of the samples.
This method was applied to environmental reference samples and samples contaminated from nuclear reprocessing. 相似文献
8.
Jerome J. La Rosa Jerzy W. Mietelski Eric Wyse 《Journal of Radioanalytical and Nuclear Chemistry》2010,283(2):385-387
Described are results and the procedure for a pilot study on 237Np content in forest litter samples from Poland in relation to their plutonium activity. Neptunium was determined by inductively
coupled plasma mass spectrometry (ICP-MS) and Pu by alpha spectrometry. Two samples originated from a location with pure global
fallout and two others from a place with about 65% of the plutonium from Chernobyl. Plutonium activities were determined twice:
at Krakow and in Monaco. The two results were consistent and 239 + 240Pu activities ranged from about 1 to about 7 Bq/kg dry weight (dw). The chemical recovery for Np was between 27 and 89%. Results
for 237Np activity concentrations were between 0.099 ± 0.005 and 2.21 ± 0.076 mBq/kg dw. Observed activity ratios were lower than
expected and could be explained by fractionation of Np against Pu in forest litter. 相似文献
9.
Wenting Bu Qiuju Guo Jian Zheng Shigeo Uchida 《Journal of Radioanalytical and Nuclear Chemistry》2017,311(2):999-1005
Surface soil samples collected in the Jiuquan region in the downwind area of the Chinese nuclear test site (CNTs) were analyzed for Pu isotopes. The 239+240Pu activities ranged from 0.025 ± 0.009 to 0.89 ± 0.16 mBq g?1, varying significantly with different sampling sites. The Dunhuang city that is located in the southwestern part of the Jiuquan region received the heaviest Pu deposition (239+240Pu activities, 0.23–0.89 mBq g?1). Most of the 240Pu/239Pu isotopic ratios were similar with that of the global fallout. However, the low values (0.080–0.147) observed in three sampling sites further supported the finding of Pu originated from CNTs in that region. 相似文献
10.
Zal U’yun Wan Mahmood Hidayah Shahar Zaharudin Ahmad Yii Mei Wo Ahmad Sanadi Abu Bakar 《Journal of Radioanalytical and Nuclear Chemistry》2010,286(1):265-272
The present distributions of 239+240Pu, 241Am and activity ratio of 241Am/239+240Pu in surface seawater of the Peninsular Malaysia east coast were studied. The surface seawater samples were collected at
30 identified stations during the expedition conducted in 2008. 239+240Pu activity concentrations in surface seawater of the studied area were in the range of 2.33 ± 0.20–7.95 ± 0.68 mBq/m3, meanwhile 241Am activity concentrations ranged from MDA to 1.90 ± 0.23 mBq/m3. The calculated activity ratios of 241Am/239+240Pu were varied and disperse distributed with the ranged of 0.12–0.53. The relationships between anthropogenic radionuclide
and oceanographic parameters such as turbidity and salinity were examined. The linearly relationships between 239+240Pu and oceanographic parameters are important for better understanding of its transport processes and behavior in the east
coast of Peninsular Malaysia marine environment. Thus, the differ of distribution of 239+240Pu, 241Am and 241Am/239+240Pu in the studied area mainly due to high affinity of 239+240Pu to associate with sinking particles, mobility nature of 241Am, degree of particle reactive of both anthropogenic radionuclides, scavenging and removal process; and others. 相似文献
11.
Cizdziel JV Ketterer ME Farmer D Faller SH Hodge VF 《Analytical and bioanalytical chemistry》2008,390(2):521-530
Sector field inductively coupled plasma mass spectrometry (SF-ICPMS) has been used with analysis of solution samples and laser
ablation (LA) of electrodeposited alpha sources to characterize plutonium activities and atom ratios prevalent in the western
USA. A large set of surface soils and attic dusts were previously collected from many locations in the states of Nevada, Utah,
Arizona, and Colorado; specific samples were analyzed herein to characterize the relative contributions of stratospheric fallout
vs. Nevada Test Site (NTS) plutonium. This study illustrates two different ICPMS-based analytical strategies that are successful
in fingerprinting Pu in environmental soils and dusts. Two specific datasets have been generated: (1) soils are leached with
HNO3-HCl, converted into electrodeposited alpha sources, counted by alpha spectrometry, then re-analyzed using laser ablation
SF-ICPMS; (2) samples are completely dissolved by treatment with HNO3-HF-H3BO3, Pu fractions are prepared by extraction chromatography, and analyzed by SF-ICPMS. Optimal laser ablation and ICPMS conditions
were determined for the re-analysis of archived alpha spectrometry “planchette” sources. The best ablation results were obtained
using a large spot size (200 μm), a defocused beam, full repetition rate (20 Hz) and scan rate (200 μm s−1); LA-ICPMS data were collected with a rapid electrostatic sector scanning experiment. Less than 10% of the electroplated
surface area is consumed in the LA-ICPMS analysis, which would allow for multiple re-analyses. Excellent agreement was found
between 239+240Pu activities determined by LA-ICPMS vs. activity results obtained by alpha spectrometry for the same samples ten years earlier.
LA-ICPMS atom ratios for 240Pu/239Pu and 241Pu/239Pu range from 0.038–0.132 and 0.00034–0.00168, respectively, and plot along a two-component mixing line (241Pu/239Pu = 0.013 [240Pu/239Pu] – 0.0001; r
2 = 0.971) with NTS and global fallout end-members. A rapid total dissolution procedure, followed by extraction chromatography
and SF-ICPMS solution Pu analysis, generates excellent agreement with certified 239+240Pu activities for standard reference materials NIST 4350b, NIST 4353, NIST 4357, and IAEA 385. 239+240Pu activities and atom ratios determined by total dissolution reveal isotopic information in agreement with the LA-ICPMS dataset
regarding the ubiquitous mixing of NTS and stratospheric fallout Pu sources in the regional environment. For several specific
samples, the total dissolution method reveals that Pu is incompletely recovered by simpler HNO3-HCl leaching procedures, since some of the Pu originating from the NTS is contained in refractory siliceous particles. 相似文献
12.
C. J. Sanders J. M. Smoak L. M. Sanders M. N. Waters S. R. Patchineelam M. E. Ketterer 《Journal of Radioanalytical and Nuclear Chemistry》2010,283(3):593-596
A sediment core was taken to determine if sediment accumulation rates could be conducted using 240+239Pu signatures in the coastal mangrove mudflats of southeastern Brazil. The results from this study show that 240+239Pu fallout activities are sufficient and well preserved in the coastal sediments of this region. Sediment accumulation rates
determined from the 240+239Pu signatures were 4.4 mm/year and 4.1 from 210Pb (CIC) method. A sediment mixing coefficient rate was calculated using chlorophyll-a profile (9.5 cm2). 相似文献
13.
Dagmara I. Strumińska-Parulska Bogdan Skwarzec 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(3):1693-1703
In the paper the results of 241Pu activity concentration determination in the biggest Polish rivers are presented. The analysis of more than 100 river water samples showed the Vistula and the Odra as well as three Pomeranian Rivers are important sources of 241Pu in the southern Baltic Sea. There were differences in 241Pu activities depending on season and sampling site and the plutonium contamination came mainly from the global atmospheric fallout as well as the Chernobyl accident, which is confirmed by plutonium activity ratios of 241Pu/239+240Pu and 238Pu/239+240Pu. 相似文献
14.
R. F. Payne S. B. Clark J. T. Elliston 《Journal of Radioanalytical and Nuclear Chemistry》2008,277(1):269-274
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. 相似文献
15.
D. Arginelli G. Berton S. Bortoluzzi G. Canuto F. Groppi M. Montalto M. Nocente S. Ridone M. Vegro 《Journal of Radioanalytical and Nuclear Chemistry》2008,277(1):65-71
Many biological samples (urines and faeces) have been analyzed by means of chromatographic extraction columns, utilizing two
different resins (AG 1-X2 resin chloride and TRU), in order to detect the possible internal contamination of 239+240Pu and 241Am for some workers of a reprocessing nuclear plant in the decommissioning phase. The results obtained show on one hand the
great suitability of the first resin for the determination of plutonium, and on the other, the great selectivity of the second
one for the determination of americium. 相似文献
16.
S. K. Aggarwal D. Alamelu P. S. Khodade P. M. Shah 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(3):775-778
Determination of 238Pu in plutonium bearing fuels is required as a part of the chemical quality assurance of nuclear fuels. In addition, the determination
of 238Pu is required in nuclear technology for many other applications, e.g., for developing isotope correlations and while using
238Pu as a spike (tracer) in isotope dilution α-spectrometry (IDAS). This determination usually involves the use of α-spectrometry on purified Pu sample. In view of the random errors associated with the counting statistics and the systematic
errors due to (1) in-growth of 241Am in purified Pu sample and (2) tail contribution correction methodology in α-spectrometry, the precision and accuracy obtainable by α-spectrometry are limited. Thermal ionization mass spectrometry (TIMS) is generally used for the determination of different
Pu isotopes other than 238Pu. This is due to the ubiquitous isobaric interference from 238U at 238Pu in TIMS. Recently, we have carried out studies on the formation of atomic and oxide ions of U and Pu by TIMS and developed
a novel approach using interfering element correction methodology to account for the isobaric interference of 238U at 238Pu in TIMS. This methodology is based on the addition of 235U (enrichment >90 atom%) to Pu sample followed by the determination of 238U/235U atom ratio using UO+ ion and determination of Pu isotope ratios using Pu+ ion, from the same filament loading. The TIMS methodology was used for the determination of 238Pu in different Pu samples in U based nuclear fuels from PHWRs with 238Pu content about 0.2 atom%. The 238Pu determination was also carried out using α-spectrometry. This paper reports the results obtained by the two methods and presents the ments and shortcomings of the two
approaches. 相似文献
17.
Sherrod L. Maxwell Brian A. Culligan Vernon D. Jones Sheldon T. Nichols Gary W. Noyes 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(1):223-230
A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of 237Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry. 238U can interfere with 239Pu measurement by ICP-MS as 238UH+ mass overlap and 237Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and short-lived Pu isotopes can be measured successfully. The method allows for simultaneous extraction of 20 samples (including QC samples) in 4?C6 h, and can also be used for emergency response. 239Pu, 242Pu and 237Np were measured by ICP-MS, while 236Pu, 238Pu, and 239Pu were measured by alpha spectrometry. 相似文献
18.
B. Lukšienė E. Maceika N. Tarasiuk E. Koviazina V. Filistovič Š. Buivydas A. Puzas 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(1):277-286
Distributions of 239,240Pu, 238Pu and 137Cs activity concentrations in the cores of sediments in the shallow lake, flooded and upland forest soils taken in the vicinity of Vilnius city were analyzed. The radiochemical, α-spectrometric and mass spectrometric methods were used for the plutonium evaluation and γ-spectrometry was used for the radiocesium evaluation. The only peak of enhanced radionuclide activity concentrations was determined for the lake bottom sediments, whereas vertical profiles of the radionuclide activity concentrations in flooded and upland forest soil cores were distinguished by two peaks. The obtained values of the activity concentration ratio 238Pu/239,240Pu and the isotopic ratio 240Pu/239Pu indicated that the global fallout was a source of plutonium in the investigated environment. Chernobyl-derived radiocesium was detected solely in the surface layers (2–11 cm) of the studied sample cores. The contribution of the Chernobyl deposits amounted to about 2.26, 6.11 and 20.9 % of the total radiocesium inventory in the bottom sediments, the upland soil and flooded soil, respectively. 相似文献
19.
Donard OF Bruneau F Moldovan M Garraud H Epov VN Boust D 《Analytica chimica acta》2007,587(2):170-179
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. 相似文献
20.
A. D. Sajeniouk 《Journal of Radioanalytical and Nuclear Chemistry》2005,264(2):337-342