Determination Of 137Cs Research Articles

Determination of 137Cs in Natural Water and Waste Streams Using Ferrocyanide Sorbents Based on Various Supports: a Comparative Analysis

Determination of 137Cs in Natural Water and Waste Streams Using Ferrocyanide Sorbents Based on Various Supports: a Comparative Analysis

Innovative methods for determination of 90Sr and 137Cs in soil samples based on effective radiochemical separation and beta-counting

– Innovative methods were developed for direct 90Sr and 137Cs determination in soils by radiochemical separation and β-counting. Studies focused on: (1) the suitability of PEG to remove silica by coating, (2) the decontamination effect of Cs from 40K, (3) iron elimination with Microthene-TOA column instead of oxalate complex, and (4) the effective separation of Y and Sr from Pb by a Microthene-TOA column which made the direct 90Sr determination possible in less time with just one resin-column. The methods were validated by analysing the IAEA reference materials, showing good agreement with the recommended values. The methods were used to determine 90Sr and 137Cs in 21 soil samples. The obtained 90Sr concentrations in the soils were in the range of 0.46–2.95 Bq kg−1, while 137Cs 1.24–35.5 Bq kg−1. The yields of yttrium and caesium were 73.4 ± 8.0% and 79.0 ± 9.1%, respectively.

Побудова картосхем щільності забруднення 137Cs сільськогосподарських угідь за сукупністю результатів обстеження

A methodology for mapping the density of 137Cs contamination of agricultural land is proposed and tested. The methodology is based on data on gamma-dose rate measurements, gamma-logging results, and direct determination of 137Cs in soil samples, which were obtained by different organizations in different years. It allows to generalize all available information on 137Cs contamination of the lands and significantly improves the representativeness of estimates of the spatial distribution of the radionuclides at the mapping.

137Cs, 40K and 210Po in abiotic components of aquatic ecosystems two rivers in the Can Gio biosphere reserve, Vietnam

Determination of 137Cs, 40K and 210Po in water, bottom sediments and suspended matter of river systems of the Can Gio Biosphere Reserve, Vietnam was carried out. The average activity concentration of 137Cs in waters of Ca Gau and Long Tau was 0.89 ± 0.14 and 1.08 ± 0.15 Bq m−3 and was comparable to the levels of this radioisotope in waters of the East Sea. The activity concentration of 137Cs in bottom sediments was 2.23 ± 0.81 and 3.63 ± 1.24 Bq kg−1. The activity concentration of 137Cs in water and bottom sediments could be characterized as low. So, the water areas of the Ca Gau and Long Tau rivers could be attributed to areas with insignificant pollution by technogenic radionuclides. The 210Ро activity concentration in bottom sediments of the Ca Gau and Long Tau rivers ranged from 9.2 ± 1.2 to 25.5 ± 2.1 Bq kg−1, which is typical for river bottom sediments. Such values indicate the absence of anthropogenic enhancement of the entry of this radionuclide into the Can Gio river systems. The 40K activity concentration varied within 467 ± 42–651 ± 39 Bq kg−1 and represented typical values of potassium content in the bottom sediments of coastal water bodies, subject to a significant influence of the lithogenic component of suspended matter.

Determination Of 137CS In Batam Water As South China Sea Extention Using Ammonium Phospomolibdate (AMP) Method

A Study of the Characteristics of the 137Cs of the South China Sea in Batam Waters has been carried out. The South China Sea through several straits is connected to the Pacific Ocean region and the Indonesian Sea. The mass of Pacific water entering the South China Sea will reach Batam Waters with radioactive contaminants. Batam Waters are part of the Karimata Strait which is the Extention Line of South China Sea so that it has the potential to receive 137Cs of radioactive contaminants from operational nuclear reactors discharged in the coastal regions of China. The purpose of the study is to find out the characteristics of 137Cs and obtain the current status of 137Cs as a baseline to minimize the impact of nuclear activities on the ecosystem of the waters of Batam, Indonesia. The 137Cs characterization method uses the Ammonium Phosphomolibdate (AMP) with modification of base dissolution and measurement validation with Certified Reference Material (CRM). The results of monitoring the concentration of 137Cs in seawater in Batam waters are in the range <0.03 - 0.35 ± 0.02 Bq.m-3, while the concentration of 137Cs activity in Batam waters sediments is known to be a maximum of 0.22 ± 0.08 Bq.kg-1 with 134Cs below MDA. Result in seawater and sediments are comparable to previous research related to the presence of radiocesium in the region

Resolving isobaric interference towards the determination of 137Cs and 90Sr using laser-ionization mass spectrometry

Resolving isobaric interference in situ using laser-ionization mass spectrometry (LIMS).

Sensitive and accurate methods for determination of low activity level of 90Sr and 137Cs in grass/vegetable samples

Sensitive, precise and accurate methods for determination of low activity level of 90Sr and 137Cs in grass/vegetable samples by a low background β-counter were developed. The method for 90Sr determination was based on coprecipitation as carbonate, elimination of 210Bi and iron with a Microthene-TOA column, separation of 90Y with a Microthene-HDEHP column, and source preparation as Y2(C2O4)3. The method for 137Cs determination was based on Cs adsorption on ammonium molybdophosphate and precipitation as Cs3Bi2I9 for source preparation. The quality control tests indicated that the methods could provide accurate results. The method application showed that: (1) The mean yields of yttrium and cesium were 79 ± 6% and 84 ± 2%, respectively. (2) The activity concentrations of 90Sr in 9 grass/vegetable samples were in the range of 0.04–1.8 Bq kg−1, while that of 137Cs in the range of 0.022–0.18 Bq kg−1. And (3) the uptake rate of 90Sr from soil to grass/vegetable was much higher than that of 137Cs.

Determination of 137Cs in Sea Water Samples Using Gamma Spectrometry

In the present study a comparative evaluation of two methods for 137Cs determination (pretreatment for gamma spectrometry) is attempted. One of them is the conventional AMP (ammonium molybdophosphate, (ΝΗ4)3Ρ(Μo3O10)4) method (radiochemical treatment based on coprecipitation) and the other one is a method based on pre-concentration of cesium in situ by using the Mark III Centrifugal Pump. The pump, which is described analytically in the study, is composed of a mo­tor (pump), four cartridge housings (containing the scavengers), a flow meter and a pressure tube (containing the battery pack and the timer board). For justification, this method is compared with the AMP co-precipitation one. Following up the radioanalytical procedures, the gamma spectrometry system (relative efficiency of high purity germanium detector 90%) is also demonstrated, as conformed to mea­ suring obtained parameters. Finally, the advantages and disadvantages of these two methods are recorded and the application of each one is suggested.

Modified biosorbent wood-decay fungus Fomes fomentarius for pre-concentration of 137Cs in water samples

The biosorbent used in this study was prepared from wood-decay fungus Fomes fomentarius. The chemical modification of biosorbent with potassium–copper hexacyanoferrate (KCuHCF) for cesium sorption in aqueous solutions studies was used. It was found that the biosorbent has a high 137Cs absorbability in the wide range of pH, even in the solutions with high ionic strength. The developed method for 137Cs determination by using modified bio-sorbent was applied to various types of water delivered by the Water Research Institute in Bratislava. 137Cs was measured on HPGe detector and 137Cs activity was less than the minimum detectable activity (5mBq L−1). The tested modified bio-sorbent is suitable for pre-concentration of 137Cs from water.

Determination of 137Cs in large volume seawater using Cu-hexacyanoferrate cartridge filters

A simple method to determine 137Cs in seawater has been developed based on the use of a Cu-hexacyanoferrate scavenger. The Cu-hexacyanoferrate supported on cotton wound cartridge filter was used to absorb 137Cs from seawater by passing large volumes over the cartridge filters with flowrate of 240 L hr-1. Results from the Cu-hexacyanoferrate method were proved acceptable for accuracy with bias below ± 20 % i.e. - 9.16 to + 18.55 % when compared with the traditional ammonium molybdophosphate pre-concentration method. This developed method is cost-effective and less time consuming. In addition it can be easily performed at sampling fields.

Establishing a high-resolution surface sediment chronology with multiple dating methods – Testing 137Cs determination with Nurmijärvi clastic-biogenic varves

Abstract The uppermost 50 cm of sediments from the 23 m deep lacustrine basin of Nurmijarvi, a lake in south-central Finland, are composed of the clastic-biogenic type of varves. We use multiple dating methods to render a sediment chronology that is as precise and accurate as possible for future paleoenvironmental research on this high-fidelity sedimentary archive. The 250-year-long varve chronology contains a chronological error of ±2%, as estimated based on repeated varve counts. The varve-based chronology was verified with the vertical distribution of 137Cs by comparing variations in the paleomagnetic relative declination of the surface sediments with instrumental observations and a calculated representation of declination features in Finland. A comparison of the sediment cesium content using two gamma counters, different sediment pretreatments, and normalization of the 137Cs concentration with masses and accumulation rates of different sediment components revealed that the AD 1986 fallout peak from the Chernobyl accident is the dominant feature in the studied sediments, regardless of the sample pretreatment or normalizing procedure. The vertical distribution of the AD 1986 peak in sediments with clastic-biogenic varves is fairly narrow, thus providing an accurate age-depth marker for the recent deposits. However, the Nurmijarvi section also reveals a ca. 10-year-long period of catchment-to-basin 137Cs mobilization and redeposition after the AD 1986 fallout, as well as significant downwards diffusion of the Chernobyl-derived cesium in the sediment. This study highlights the ways in which the quality of surface sediment chronology needs to be considered and secured prior to comparisons between paleoproxy records and instrumental observations.

Combined, sequential procedure for determination of 137Cs, 40K, 63Ni, 90Sr, 230,232Th, 234,238U, 237Np, 238,239+240Pu and 241Am applied for study on contamination of soils near Żarnowiec Lake (northern Poland).

The paper summarizes results of investigation of the current state of radioactive contamination on site being under consideration for planned nuclear power plant in northern Poland. Thanks to use of sequential procedure it was possible to determine activity concentrations for radioisotopes of nine elements, both natural and artificial. Results show that observed levels of radioactive contamination are rather typical for central Europe and global fallout is dominant factor of presence of artificial radionuclides. The total deposition for artificial radionuclides revealed maxima equal to 1747 ± 121 Bq/m2 for 137Cs, 3854 ± 158 Bq/m2 for 90Sr, 101 ± 23 mBq/m2 for 237Np, 57.7 ± 6.0 Bq/m2 for 241Am, 3.27 ± 0.80 Bq/m2 for 238Pu and 68.5 ± 5.0 Bq/m2 for 239+240Pu.

The use of ferrocyanide Zn/Al-hydrotalcite for the sorptive concentration and radiometric determination of 137Cs in waters

A sorbent based on Zn/Al-hydrotalcite intercalated by hexacyanoferrate (II)-ions is proposed for 137Cs concentration and its further radiometric determination in natural waters. Parameters for the optimal sorptive extraction of radiocesium from waters under static conditions and direct radiometric measurements have been determined. The use of ferrocyanide sorbent is shown to provide a good potential in analytical schemes of 137Cs concentration from waters with high salt background.

A preliminary study for the development of reference material using oyster for determination of 137Cs, 90Sr and plutonium isotopes

A new reference material for the determination of 137Cs, 90Sr and Pu isotopes (238Pu and 239,240Pu) is being developed using dried oyster matrix by Korea Research Institute of Standards and Science (KRISS). The oyster was collected from Tongyoung harbour, southern part of Korea and the artificial radionuclides (137Cs, 90Sr, 238Pu and 239,240Pu) were spiked into the material. After pretreatment and processing, the material was tested for homogeneity and massic activities were determined by measuring 137Cs, 90Sr, 238Pu and 239,240Pu. The reference value and extended uncertainty for those isotopes will be reported later.

Determination of 137Cs and 60Co pollution in the area of the Laguna Verde Nuclear Power Plant, Mexico.

The project 'Radiological Analysis of Environmental Samples in the Gulf of Mexico and the coast of Quintana Roo', had the aim of identifying and quantifying anthropogenic radionuclides in environmental samples consisting of silt, sand and sea water. This paper presents the results of the radiological analysis of these samples, which was made in the multichannel system for gamma spectrometry with hyperpure germanium detector in the Laboratory of Radiological Analysis of Environmental Samples, located at the Physics Department, Faculty of Sciences, of the Autonomous National University of Mexico (UNAM). The sampled points are along the coast of the contiguous states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatan and Quintana Roo. This paper presents the qualitative and quantitative concentrations of the main identified anthropogenic radionuclides (60)Co and (137)Cs.

Determination of 135Cs by accelerator mass spectrometry

The ratio of anthropogenic 135Cs and 137Cs isotopes is characteristic of a uranium fission source. This research evaluates the technique of isotope dilution (yield tracing) for the purpose of quantifying 135Cs by accelerator mass spectrometry with on-line isobar separation. Interferences from Ba, Zn2, and isotopes of equal mass to charge ratios were successfully suppressed. However, some sample crosstalk from source contamination remains. The transmission and di-fluoride ionization efficiencies of Cs isotopes were found to be 8×10−3 and 1.7×10−7 respectively. This quantification of 135Cs using yield tracing by accelerator mass spectrometry shows promise for future environmental sample analysis once the issues of sample crosstalk and low efficiency can be resolved.

Determination of ¹³⁵Cs and ¹³⁵Cs/¹³⁷Cs atomic ratio in environmental samples by combining ammonium molybdophosphate (AMP)-selective Cs adsorption and ion-exchange chromatographic separation to triple-quadrupole inductively coupled plasma-mass spectrometry.

Since the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011, the activity ratio of (134)Cs/(137)Cs has been widely used as a tracer for contamination source identification. However, because of the short half-life of (134)Cs (2.06 y), this tracer will become unavailable in the near future. This article presents an analytical method for the determination of the long-lived (135)Cs (t(2/1) = 2 × 10(6) y) and the atomic ratio of (135)Cs/(137)Cs, as a promising geochemical tracer, in environmental samples. The analytical method involves ammonium molybdophosphate (AMP)-selective adsorption of Cs and subsequent two-stage ion-exchange chromatographic separation, followed by detection of isolated radiocesium isotopes via triple-quadrupole inductively coupled plasma-mass spectrometry (ICP-MS/MS). The AMP-selective adsorption of Cs and the chromatographic separation system showed high decontamination factors (10(4)-10(5)) for interfering elements, such as Ba, Mo, Sb, and Sn. Using ICP-MS/MS, only selected ions enter the collision/reaction cell to react with N2O, reducing the isobaric interferences ((135)Ba(+) and (137)Ba(+)) and polyatomic interferences ((95) Mo(40)Ar(+), (97) Mo(40)Ar(+), (119)Sn(16)O(+), and (121)Sb(16)O(+)) produced by sample matrix ions. The high abundance sensitivity (10(-9) for the (135)Cs/(133)Cs ratio) provided by ICP-MS/MS allowed reliable analysis of (135)Cs and (137)Cs isotopes with the lowest detection limits ever reported by mass counting methods (0.01 pg mL(-1) and 0.006 pg mL(-1), respectively). The developed analytical method was successfully applied to the determination of (135)Cs and (137)Cs isotopes in environmental samples (soil, litter, and lichen) collected after the FDNPP accident for contamination source identification.

Analytical methods for the determination of 137Cs and 90Sr in ash of fuel pellets used in Italy

In this study the radiological characterization of ashes of 22 different brands of wood pellets coming from different countries and used in the regions of central Italy was carried out. 137Cs and 90Sr, were found in the samples taken into account, 134Cs resulted always below the detection limit. 137Cs activity concentration ranges from 30 to 3176Bqkg−1 (the arithmetic mean resulted to 571Bqkg−1); 90Sr activity concentration ranges from 154.75Bqkg−1 to 1443.70Bqkg−1 (the arithmetic mean resulted to 684.80Bqkg−1). The ratio of 90Sr and 137Cs activity concentration ranged from 0.22 to 40.79 showing a high variability. 77.2% of the samples show a 90Sr activity concentration higher than that of 137Cs. The concentration factors (activity concentration in ash/activity concentration in wood pellets) resulted to 222.8 and 230.0 for 137Cs and 90Sr respectively; both radionuclides are found completely in the ashes.

Biomonitoring of 137Cs, 40K, 232Th, and 238U using oak bark in Belgrade forest, Istanbul, Turkey

In the present study, the bark of oak trees (Quercus petraea Liebl.) was collected from Belgrade Forest northwest of Istanbul for determination of 137Cs, 40K, 232Th, and 238U activity. A gamma spectrometer equipped with high-purity germanium detector was used for radioactivity measurement. Bark samples were collected from the northern and southern sides of trees at a height of 1.5 m above the ground in order to see the effects of rainfall and wind; and they were also collected from the northern side at a height of 0.5 m above the ground to assess the effect of soil splash. The activity concentrations of 137Cs, 40K, 232Th, and 238U in the bark samples were found to vary in the range of 1.40-27.50, 45.0-221.2, 0.92-9.64, and 4.04-36.10 Bq/kg, respectively. The elevated activity of 238U in bark samples could be attributed to a large amount of coal combustion in the region until the 1990s. According to one-way ANOVA, a significant difference was not found in bark samples collected at a height of 0.5 m and 1.5 m above the ground in terms of radionuclide activity. There was also no significant variation regarding radionuclide accumulation between northern and southern sides.

Monte Carlo simulation of beta radiation response function for semiconductor Si detector

Abstract This paper describes the modeling of the Passivated Implanted Planar Silicon (PIPS) detector for the beta particles response function simulations with the MCNP-5 code. The simulated and measured energy response functions were compared and a good agreement was found in the entire range of energies. The verified model of a PIPS detector was applied in a non-destructive method that determines the activity of beta emitters in the sample with a known geometry and atomic number densities. The procedure for the identification of beta emitters in the samples was also described. Finally, the application of the proposed method for the determination of 137Cs and 90Sr activity in water samples taken from the RA reactor spent fuel storage pools and from the paper filter taken from an air monitor operated during repackaging of spent fuel elements, was presented.