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1.
PLoS One ; 19(9): e0308518, 2024.
Article in English | MEDLINE | ID: mdl-39288116

ABSTRACT

This paper reports the activity concentrations of 137Cs, 90Sr, 239+240Pu, 241Am, and 3Н in the form of tritiated water (НТО) and organically bound tritium (ОBТ) in the tissues and organs of roe deer (Capreolus pygargus Pal., 1771) that inhabit the 'Degelen' test location of the Semipalatinsk Test Site. Tissues and organs were sampled from six deer by killing. The activity concentrations of specific radionuclides in the samples were measured using γ-, α-, and ß-spectrometry. The radionuclide activity concentrations in the tissues and organs showed considerable variation, for example, 0.6-170 Bq kg-1 for 137Cs and 0.3-2.8×103 Bq kg-1 for 90Sr. The activity concentrations of radionuclides in animal muscular tissue did not exceed permissible values for the meat of wild animals. The tissues and organs in the roe deer were arranged as follows in descending order of their ability to accumulate 137Cs and 90Sr: for 137Cs, muscular tissue-kidneys-lungs-spleen-heart-liver-bone tissue; for 90Sr, bone tissue-liver-lungs-muscular tissue-spleen-heart-kidneys. The activity concentrations of 241Am and 239+240Pu did not exceed the minimum detectable activity. Therefore, no quantitative values could be determined for 241Am, and the 239+240Pu activity concentration could be derived for only one sample: 0.5±0.1 Bq kg-1 (liver). The distribution pattern of these radionuclides in the tissues and organs of the roe deer could not be determined because of insufficient data. The HTO volumetric activity in the tissues and organs of the examined animals ranged from 2.6×10-2 to 77 kBq l-1; activity concentration of OBT, 3.0×10-2 to 16 kBq kg-1; and OBT-to-HTO ratios, 2.0×10-3 to 5.3×102. This ratio can serve as an indicator of how long the examined animals stay in radioactively contaminated ecosystems. Within the 'Degelen' site, the activity concentrations of 90Sr and tritium, in the form of HTO and OBT, are expected to be high in the bone tissues, soft tissues, and organs, respectively.


Subject(s)
Cesium Radioisotopes , Deer , Strontium Radioisotopes , Animals , Strontium Radioisotopes/analysis , Cesium Radioisotopes/analysis , Plutonium/analysis , Nuclear Weapons , Radiation Monitoring/methods , Americium/analysis , Siberia , Tritium/analysis
2.
Radiat Prot Dosimetry ; 200(15): 1486-1491, 2024 Sep 19.
Article in English | MEDLINE | ID: mdl-39231500

ABSTRACT

This study compares the performance of old and new lung counters in the National Institutes for Quantum Sciences and Technology of Japan. The total sensitive area of the detector crystals for the new lung counter is ~15% smaller than that for the old lung counter. Minimum detectable activities (MDAs) for 241Am and 239Pu were evaluated through experiments using a Lawrence Livermore National Laboratory torso phantom. Despite differences in detector configuration, the MDAs were found to be comparable between the two lung counters. For a chest wall thickness of 2.1 cm and a counting time of 30 min, the MDAs of 241Am and 239Pu were 5.7 and 2300 Bq for the old lung counter, and 5.5 and 2600 Bq for the new lung counter, respectively. Experimental results for the relative sensitivities between left-side and right-side detectors suggested that the new lung counter offered better measurement geometry.


Subject(s)
Americium , Lung , Phantoms, Imaging , Lung/radiation effects , Humans , Americium/analysis , Plutonium/analysis , Radiation Dosage , Equipment Design , Japan
3.
Radiat Prot Dosimetry ; 200(15): 1443-1449, 2024 Sep 19.
Article in English | MEDLINE | ID: mdl-39231508

ABSTRACT

This study investigated the feasibility of a simplified method of alpha spectroscopy for radionuclidic purity tests at 225Ac production sites that eliminates the need for a vacuum chamber. The impact of enhancing the energy resolution using a collimator was evaluated through radiation transport simulations. The results showed that a full width at tenth maximum (FWTM) of <300 keV was achieved for alpha particles from 241Am, for which the main energy peak was 5.5 MeV. Experimental validation using an electrodeposition source containing 237Np, 241Am, and 244Cm confirmed an FWTM of 272 keV for both 241Am and 244Cm. These two peaks, with a difference of ~300 keV, were effectively separated. In response to the growing demand for targeted radioisotope therapy, this simplified alpha spectroscopy method offers the potential to detect 226Ra mixed with 225Ac generated by accelerators, given the alpha energy difference of ~700 keV.


Subject(s)
Alpha Particles , Americium , Americium/analysis , Actinium/chemistry , Spectrum Analysis/methods , Particle Accelerators/instrumentation , Computer Simulation , Monte Carlo Method
4.
Radiat Prot Dosimetry ; 200(15): 1416-1424, 2024 Sep 19.
Article in English | MEDLINE | ID: mdl-39216993

ABSTRACT

A 241Am gamma (γ)-ray calibration field that meets the requirements for a γ-ray reference field as specified in the ISO 4037 standard series was established in the Facility of Radiation Standards of the Japan Atomic Energy Agency. The reference air kerma rates were measured using a reference ionization chamber calibrated by the N-80 quality X-ray calibration field of the national metrology standard in Japan and with a correction to account for differences in photon energy due to the calibration field. Conversion coefficients for the 241Am γ-ray calibration field, including those not listed in the ISO 4037 standard series, were calculated based on the measured γ-ray fluence rate spectra.


Subject(s)
Americium , Gamma Rays , Calibration , Americium/analysis , Japan , Reference Standards , Radiation Dosage , Radiation Monitoring/methods , Radiation Monitoring/standards , Radiometry/standards , Radiometry/methods , Photons
5.
J Environ Radioact ; 278: 107505, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39043063

ABSTRACT

Three nuclear weapons tests were conducted in the 1950s at the Montebello Islands, Western Australia. The detonations were of different yields and configurations (two tower tests, one ship test), and led to substantial radionuclide contamination within the surrounding terrestrial and marine ecosystems. The region possesses great ecological and recreational significance, particularly within the marine environment. However, studies conducted so far have largely neglected the marine ecosystem which makes up the majority of the Montebello Island Marine Park and in which most test fallout would have deposited. Here we investigated the distribution of the transuranic radionuclides 238Pu, 239,240Pu and 241Am in marine sediment from the Montebello Islands. Marine sediment samples near Operation Mosaic G2 and Operation Hurricane were collected and analysed by gamma and alpha spectrometry. Activity concentrations of 239,240Pu across both series ranged from 45 to 2900 Bq kg-1, while 241Am levels ranged from 2.8 to 70 Bq kg-1. Higher activity concentrations were observed in sediment near the land-based, higher yield Mosaic G2 test, compared with the ship-based, lower yield Hurricane test. Sediment samples located closer to the detonation site were also observed to have higher activity concentrations. Radioactive particles of 0.94 mm and 1.5 mm in diameter were identified by analysis of size-fractioned sediment via investigation of 152Eu levels, photostimulated autoradiography and point gamma spectroscopy. Particles were confirmed to have transuranic radionuclide interiors, with surface coatings which were dominated by vitrified CaCO3. Their long-term resistance to weathering and subsequent persistence in the marine environment can therefore be attributed to their coated structural form. Our study confirms the persistence of transuranic radionuclides in Montebello Island marine sediment and highlights the need for additional studies to improve our understanding of the nuclear legacy in this region.


Subject(s)
Geologic Sediments , Plutonium , Radiation Monitoring , Water Pollutants, Radioactive , Geologic Sediments/chemistry , Geologic Sediments/analysis , Western Australia , Plutonium/analysis , Water Pollutants, Radioactive/analysis , Americium/analysis , Islands , Nuclear Weapons
6.
J Environ Radioact ; 278: 107506, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39053127

ABSTRACT

For the quality control in determining transuranic nuclides in fallout samples, this work first reported the 237Np activity concentration in a reference fallout material and further calculated the activity ratios of 237Np/239+240Pu and 237Np/241Am, and the atom ratio of 237Np/239Pu in it. The reference fallout material prepared by the Meteorological Research Institute was collected at 14 stations throughout Japan in 1963-1979. The 237Np and Pu isotopes (239Pu and 240Pu) were separated and purified using AG MP-1M anion-exchange resin, quantified using 242Pu as an isotope dilution tracer, and determined by the SF-ICP-MS. The analytical method was validated by the analysis of 4 sediment reference materials. The activity concentrations of 237Np, 239Pu and 240Pu were (25.9 ± 0.6) × 10-3, 4.10 ± 0.01 and 2.89 ± 0.04 Bq/kg, respectively, in the investigated reference fallout material. The activity ratio of 237Np/239+240Pu (3.7 ± 0.1) × 10-3 was consistent with the global fallout evaluation value. The 237Np/239Pu atom ratio of 0.561 ± 0.014 was higher than the average global fallout value of 0.41 ± 0.010, indicating the necessity of establishing regional characteristic global fallout value of 237Np/239Pu atom ratio for assessment of radioactive contamination. Comparison of the 237Np/239+240Pu activity ratios between in the reference fallout material and in soils over several decades indicated that 237Np has stronger migration capability than Pu isotopes in soils because 237Np was depleted compared to reference fallout material.


Subject(s)
Plutonium , Radiation Monitoring , Radioactive Fallout , Radiation Monitoring/methods , Radioactive Fallout/analysis , Plutonium/analysis , Japan , Mass Spectrometry/methods , Soil Pollutants, Radioactive/analysis , Americium/analysis , Neptunium/analysis
7.
Radiat Prot Dosimetry ; 200(8): 721-738, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38690853

ABSTRACT

This paper describes a procedure for the estimation of 241Am and 239Pu activity present in the human tissue by measuring the depth of contaminant using a portable Planar High Purity Germanium detector (HPGe). The ratios of photopeak counts of X-rays or gammas obtained with the detector coupled to collimator are calculated for the estimation of depth of the contaminant and the optimum one is determined. Since Minimum Detectable Activities (MDA) for the detector coupled to a collimator are higher than that of bare detector, activity must be estimated using bare detector, after locating the contaminant. Two methods are described for the estimation of plutonium coexisting with 241Am: (i) Abundance and isotopic correction for 239Pu (ii) and 239Pu:241Am ratio. The procedure to estimate 239Pu when plutonium isotopes alone are present is also established. An optimum monitoring period to detect the minimum value of intake for both radionuclides corresponding to chelation therapy and excision is also derived.


Subject(s)
Americium , Germanium , Plutonium , Plutonium/analysis , Americium/analysis , Humans , Germanium/analysis , Radiation Monitoring/methods , Radiation Monitoring/instrumentation , Radiation Dosage , Radiometry/methods , Radiometry/instrumentation
8.
J Environ Radioact ; 275: 107430, 2024 May.
Article in English | MEDLINE | ID: mdl-38615506

ABSTRACT

Clay colloids in the subsurface environment have a strong adsorption capacity for radionuclides, and the mobile colloids will carry the nuclides for migration, which would promote the movability of radionuclides in the groundwater environment and pose a threat to the ecosphere. The investigations of the adsorption/desorption behaviors of radionuclides in colloids and porous media are significant for the evaluation of the geological disposal of radioactive wastes. To illustrate the adsorption/desorption behaviors of 241Am(Ⅲ) in Na-montmorillonite colloid and/or quartz sand systems at different pH (5, 7 and 9), ionic strengths (0, 0.1 and 5 mM), colloid concentrations (300 and 900 mg/L), nuclide concentrations (500, 800, 1100 and 1400 Bq/mL) and grain sizes (40 and 60 mesh), a series of batch sorption-desorption experiments were conducted. Combining the analysis of the physical and chemical properties of Na-montmorillonite with the Freundlich model, the influencing mechanism of different controlling factors is discussed. The experimental results show that the adsorption/desorption behaviors of 241Am(Ⅲ) in Na-montmorillonite colloid and/or quartz sand strongly are influenced by the pH value and ionic strength of a solution, the colloid concentration as well as quartz sand grain size. The adsorption and desorption isotherms within all the experimental conditions could be well-fitted by the Freundlich model and the correlation coefficients (R2) are bigger than 0.9. With the increase in pH, the adsorption partition coefficient (Kd) at 241Am(Ⅲ)-Na-montmorillonite colloid two-phase system and 241Am(Ⅲ)-Na-montmorillonite colloid-quartz sand three-phase system presents a trend which increases firstly followed by decreasing, due to the changes in the morphology of Am with pH. The Kd of 241Am(Ⅲ) adsorption on montmorillonite colloid and quartz sand decreases with increasing in ionic strength, which is mainly attributed to the competitive adsorption, surface complexation and the reduction of surface zeta potential. Additionally, the Kd increases with increasing colloid concentrations because of the increase in adsorption sites. When the mean grain diameter changes from 0.45 to 0.3 mm, the adsorption variation trends of 241Am(Ⅲ) remain basically unchanged. The research results obtained in this work are meaningful and helpful in understanding the migration behaviors of radionuclides in the underground environment.


Subject(s)
Americium , Bentonite , Colloids , Quartz , Bentonite/chemistry , Osmolar Concentration , Adsorption , Hydrogen-Ion Concentration , Colloids/chemistry , Quartz/chemistry , Americium/chemistry , Americium/analysis , Water Pollutants, Radioactive/chemistry , Water Pollutants, Radioactive/analysis , Soil Pollutants, Radioactive/analysis , Soil Pollutants, Radioactive/chemistry , Models, Chemical , Particle Size , Sand/chemistry
9.
Mar Pollut Bull ; 202: 116305, 2024 May.
Article in English | MEDLINE | ID: mdl-38593714

ABSTRACT

The contamination of the Baltic Sea with radioactive substances occurred due to the global fallout of atmospheric nuclear weapon tests and the Chernobyl disaster. The knowledge of 241Am in the sediments of the Baltic Sea is limited. Thus, this study aimed to determine 241Am in sediment cores collected from the southern Baltic Sea. Time-based distributions were derived from age-depth profiles using the 210Pb dating method and further corroborated by 137Cs profiles. The activities of 241Am were measured by alpha spectrometry after radiochemical purification. The results show divergences in the concentrations of 241Am at the local level, varying from 0.017 ± 0.001 Bq·kg-1 at the Gotland Basin station to 3.19 ± 0.23 Bq·kg-1 in the Gdansk Basin. These findings enhance our understanding of the radioactive contamination levels in the Baltic Sea and serve as a crucial reference dataset for future assessments and management strategies to mitigate the environmental impact of radionuclides in the region.


Subject(s)
Americium , Geologic Sediments , Oceans and Seas , Radiation Monitoring , Water Pollutants, Radioactive , Geologic Sediments/chemistry , Water Pollutants, Radioactive/analysis , Americium/analysis , Cesium Radioisotopes/analysis
10.
Talanta ; 270: 125607, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38169274

ABSTRACT

The 239Pu, 238U, and 241Am concentrations and 239Pu/240Pu, 235U/238U, and 236U/238U atom ratios were measured in the hair and nail samples using a new method utilized TEVA, UTEVA, and DGA extraction chromatography and multi-collector ICP-MS. Samples were collected from individuals who donated their bodies to the United States Transuranium and Uranium Registries. The concentration of 239Pu ranged from 0.22 to 15.8 ng/kg. The 240Pu/239Pu isotopic ratios ranged from 0.026 to 0.127 which is consistent with weapons-grade plutonium. Concentration of uranium fell between 1.84 µg/kg and 29.5 µg/kg and 235U/238U ratios ranged from 4.8 × 10-3 to 7.6 × 10-3. Elevated 236U/238U atom ratios were measured in two cases and ranged from 5.0 × 10-6 - 2.4 × 10-5 indicating exposure to spent or reprocessed uranium material. The concentration of 241Am was measured in four hair samples and ranged from 0.02 to 0.21 ng/kg.


Subject(s)
Plutonium , Uranium , Humans , Plutonium/analysis , Plutonium/chemistry , Uranium/analysis , Mass Spectrometry/methods , Americium/analysis , Nails/chemistry , Hair/chemistry
11.
PLoS One ; 18(11): e0294632, 2023.
Article in English | MEDLINE | ID: mdl-38011204

ABSTRACT

The article assesses the content of radionuclides in hoofed animals inhabiting the Semipalatinsk Test Site by calculation. Hoofed animals' faeces were sampled to determine the content of radionuclides in their diets. Based on values determined for the content of radionuclides in animals; diets, the content of radionuclides in the meat and milk of farm animals-cows (Bos taurus taurus), sheep (Ovis), goats (Capra hircus) and horses (Equus caballus Lin., 1758) as well as in the meat of wild animals-european moose (Alces alces Lin., 1758), argali (Ovis ammon Lin., 1758), roe deer (Capreolus pygargus Pal., 1771) and saiga (Saiga tatarica Lin., 1766) was calculated. No excess of permissible values of the content of 137Cs and 90Sr in the meat of farm animals was found to be expected, even for a conventional 'conservative' scenario, in which maxima of the radionuclide activity concentration in a vegetable feed (faeces) are taken as a basis. 241Am and 239+240Pu in the meat of farm hoofed animals are not standardized. Their predicted maxima of activity concentration are very low, and even in the 'conservative' scenario, they do not exceed 1.8×10-2 Bq kg-1, 1.4×10-1 Bq kg-1 and 1.6×10-1 Bq kg-1, respectively. In the milk of farm animals, the content of 137Cs and 90Sr does not exceed permissible values. 241Am and 239+240Pu in the milk of farm animals are not standardized. Their predicted activity concentration values in the milk of sheep and goats do not exceed 6.5×10-2 Bq l-1, for cows- 2.6×10-2 Bq l-1, for horses- 3.1×10-2 Bq l-1. Permissible values of 137Cs and 90Sr in the meat of wild hoofed animals are not exceeded either. In the meat of argali, roe deer and saigas, relatively high levels of 137Cs are predictable. 241Am and 239+240Pu in meat of wild animals are not standardized. Their predicted activity concentration values in the meat of moose and argali do not exceed 3.2×10-1 Bq kg-1 and 1.6×10-1 Bq kg-1, respectively, for roe deer and saiga-5.4×10-2 Bq kg-1. Thus, in case of free grazing in the STS territory, no excess of permissible values of standardized radionuclides (137Cs and 90Sr) in the meat and milk of hoofed animals is predictable.


Subject(s)
Deer , Plutonium , Female , Cattle , Animals , Horses , Sheep , Cesium Radioisotopes , Strontium Radioisotopes , Americium/analysis , Bioaccumulation , Animals, Domestic , Goats
12.
Radiat Prot Dosimetry ; 199(6): 540-551, 2023 Apr 19.
Article in English | MEDLINE | ID: mdl-36908190

ABSTRACT

The manganese salt bath is considered a primary standard for determining the absolute emission rate of radionuclide neutron sources. The National Research Council of Canada has recently revived its manganese salt bath and a full description of the system is given here. The physical characteristics of the bath, as well as the methods for determining the efficiency of the bath system and the induced activity in the bath, are described. An in-depth analysis of the fraction of neutrons captured in the manganese and the correction factor for neutron losses is also provided. Finally, the results of emission rate measurements of four different sources, complete with an uncertainty budget, are given. The emission rates of three americium-beryllium neutron sources and one californium-252 neutron source were found to agree with the known values, within a standard uncertainty of 1.7%.


Subject(s)
Californium , Manganese , Radiation Dosage , Calibration , Californium/analysis , Neutrons , Americium/analysis , Beryllium/analysis , Canada , Radiometry/methods
13.
PLoS One ; 18(1): e0278581, 2023.
Article in English | MEDLINE | ID: mdl-36607986

ABSTRACT

Data on the vertical distribution of radionuclides in the soil is necessary to fully understand the radioecological situation around ecosystems, give predictive estimates to how safe crop products are and justify a rehabilitation strategy for radioactively contaminated areas. A study was conducted to investigate the vertical distribution of radionuclides in soils of the former Semipalatinsk Test Site (STS) territory beyond its testing sites, that is, in areas in which no nuclear weapons or nuclear effects of radiological warfare agents were tested. Soil was sampled layerwise all over the Semipalatinsk Test Site down to 30 cm deep at a 5-cm spacing. Most of high activity concentrations of radionuclides all over the study area were detected in the 0-5 cm soil layer. Activity concentrations of the major man-made radionuclides were determined in soil samples collected by γ-, ß and α-spectrometry. As a result, ranges of activity concentrations of 137Cs, 241Am, 90Sr and 239+240Pu were determined in 0-5, 5-10, 10-15, 15-20, 20-25, 25-30 cm soil layers. In the conventionally 'background' area, the 0-5 cm soil layer, on average, contains (the percentage of total activity concentration across the soil profile depth): 137Cs- 83%, 239+240Pu- 87% and 90Sr- 38%. For the 1953 plume, these values were 92%, 83% and 73%, respectively. Values for the 1951 plume in the 0-5 cm soil layer were: 137Cs- 93%, 239+240Pu- 93% and 90Sr- 59%. The minimum concentration of radionuclides are observed 20-30 cm deep in all areas studied. 90Sr is the most mobile radionuclide from the perspective of its ability to travel deep down the soil. The study found out that the nuclide vertical migration rates downward in soils based on detected activity were as follows (in descending order): 90Sr- 137Cs- 239+240Pu- 241Am. Coefficients that determine the ratio of the activity concentration of the radionuclide in the 0-20 and 0-30 cm soil cover layers to that of this radionuclide in the 0-5 cm topsoil were calculated. These coefficients enable to estimate the radionuclide inventory at each soil sampling point from their activity concentration in the 0-5 cm soil layer.


Subject(s)
Plutonium , Soil Pollutants, Radioactive , Humans , Cesium Radioisotopes/analysis , Strontium Radioisotopes , Americium/analysis , Soil , Ecosystem , Soil Pollutants, Radioactive/analysis
14.
Radiat Prot Dosimetry ; 199(3): ncac255 187 190-190, 2023 Mar 02.
Article in English | MEDLINE | ID: mdl-36521803

ABSTRACT

The Standard Thermal Neutron Flux Unit, TNF2, in (LNMRI/IRD)(1,  2), was built for neutron detector and survey meter calibrations. The facility's fluence is achieved by moderation of four 241Am-Be with a graphite core and paraffin/graphite blocks surrounding it. Due to the small channel dimensions, it is impossible to calibrate personal dosemeters and survey meters for thermal neutrons. A polyethylene filter construction was carried out to allow the external irradiation of personal dosemeters and neutron survey meters. The polyethylene filter was constructed with 29 stacked discs with diameters ranging from 5 to 34 cm. Different thicknesses were simulated to provide the desired effect. This new irradiation configuration was also experimentally tested and compared with simulation results with MCNPX(3).


Subject(s)
Graphite , Radiation Protection , Polyethylene , Americium/analysis , Monte Carlo Method , Radiation Protection/methods , Neutrons
15.
J Environ Radioact ; 257: 107092, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36535220

ABSTRACT

Accumulation of dietary 241Am in freshwater omnivorous fish (Carassius gibelio) was studied aiming to estimate the distribution and retention of 241Am in the fish body. Amphipods labeled with 241Am served as a food item. From 0.4 to 0.6% of ingested 241Am was retained in the fish body after short courses of feeding and depuration, the trophic transfer factor of 241Am for whole organism level was about 2∙10-4.


Subject(s)
Americium , Amphipoda , Cyprinidae , Radiation Monitoring , Animals , Americium/analysis , Americium/metabolism , Food Chain
16.
J Radiol Prot ; 42(4)2022 11 24.
Article in English | MEDLINE | ID: mdl-36343358

ABSTRACT

Internal contamination by radionuclides may occur through inhalation, ingestion and absorption through the skin or subcutaneous tissue. The clinical management of internalized radionuclides requires the integration of clinical signs and symptoms with dose estimates in biological tissues obtained from the face, nose, sputum, urine, faeces and/or skin. The assessment of ingested radionuclides includes bioassays of urine and faeces, and if available, whole body counting for radionuclides that emit penetrating x-rays or gamma-rays. An estimate of intake dose may be made at the time of initial patient evaluation by measuring radioactivity, converting counts/minute to depositions/minute with a specific gamma-ray constant, and comparing the amount to its annual limit on intake, clinical decision guide or derived reference level. Since nobody dies from internal contamination per se, medically unstable patients should be stabilized before addressing internal contamination. Whenever possible, internal contaminants should be physically removed as soon as possible after exposure. For inhaled internal contaminants, radionuclide-specific therapy may include the administration of an ion exchange resin (i.e. Prussian blue, PB) or chelating agent (i.e. diethylenetriamine pentaacetate, DTPA, that binds toradioactiveplutonium, americium, and curium), or the physical removal of insoluble particles with a high activity radionuclide (192Ir,90Sr,210Po) by bronchioalveolar lavage. Decorporation with PB, DTPA and other agents is used to enhance excretion. The treatment of wounds contaminated with an actinide includes gentle irrigation, surgical excision of contaminated tissue and DTPA. The averted dose (i.e. the total effective dose averted by therapy) may be calculated for each exposure route.


Subject(s)
Plutonium , Humans , Plutonium/analysis , Decontamination , Americium/analysis , Radioisotopes , Pentetic Acid
17.
Biomolecules ; 12(11)2022 10 24.
Article in English | MEDLINE | ID: mdl-36358903

ABSTRACT

Speciation of actinides, and more particularly bioligand-binding ability, influences in vivo behavior. Understanding these interactions is essential for estimation of radiological dose and improvement of decorporation strategies for accidentally contaminated victims. Because the handling of actinides imposes overwhelming difficulties, in vitro assays carried out in physiological conditions are lacking and data regarding such interactions are scarce. In this study, we used a bi-compartmental and dynamic assay, providing physiological conditions (presence of inorganic ions, pH, temperature) to explore interactions between the actinides plutonium (Pu) and americium (Am) and endogenous (proteins transferrin and ferritin) or exogenous ligands (the chelating agent diethylenetriaminpentaacetic acid, DTPA). In this assay, an agarose gel represents the retention compartment of actinides and a dynamic fluid phase, the transfer compartment. The proportion of actinides transferred from static to dynamic phase reflects interactions between Pu/Am and various ligands. The results show differences in the formation of actinide-protein or actinide-DTPA complexes in physiologically relevant media depending on which ligand is present and where. We observed differential behavior for Pu and Am similar to in vivo studies. Thus, our assay may be used to determine the ability of various actinides to interact with specific proteins or with drug candidates for decorporation in complex physiologically relevant environments.


Subject(s)
Actinoid Series Elements , Plutonium , Ligands , Actinoid Series Elements/chemistry , Americium/analysis , Plutonium/chemistry , Pentetic Acid/chemistry
18.
Appl Radiat Isot ; 190: 110475, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36166934

ABSTRACT

This manuscript deals with the possible utilization of plastic microspheres for radiation detection. The aim was to determine the suitability of microspheres for this application, factors that affect detection efficiency, and based on the evaluation of current state technology to design and test a constructional solution suitable for this use. Three detection cell variations and their configurations, which utilize plastic microspheres, were tested for their response to selected militarily important radionuclides during a series of static measurements. Based on the results of static measurements, the most structurally suitable cell variation was subsequently tested for flow scintillation analysis. Among the cells designed for flow scintillation counting in 2π geometry, the highest achieved detection efficiency for 241Am was 13.1 ± 0.7% using Cell #5, for 90Sr/Y was 71.2 ± 3.9% using Cell #10 and for 3H was 3.9 ± 0.2% using Cell #5 respectively. Cell #10 was evaluated to perform universally the best despite achieving slightly lower detection efficiencies for 241Am and 3H than Cell #5, as the results were easily replicable and due to the cell constructional simplicity, its application was problem-free.


Subject(s)
Plastics , Strontium Radioisotopes , Strontium Radioisotopes/analysis , Americium/analysis , Microspheres , Scintillation Counting/methods
19.
Sci Total Environ ; 851(Pt 1): 158241, 2022 Dec 10.
Article in English | MEDLINE | ID: mdl-36007652

ABSTRACT

Numerous legacy near-surface radioactive waste sites dating from the mid 20th century have yet to be remediated and present a global contamination concern. Typically, there is insufficient understanding of contaminant release and redistribution, with invasive investigations often impractical due to the risk of disturbing the often significantly radiotoxic contaminants. Consequently, a replica waste trench (~5.4 m3), constructed adjacent to a legacy radioactive waste site (Little Forest Legacy Site, LFLS), was used to assist our understanding of the release and mixing processes of neodymium (Nd) - a chemical analogue for plutonium(III) and americium(III), two significant radionuclides in many contaminated environments. In order to clarify the behaviour of contaminants released from buried objects such as waste containers, a steel drum, representative of the hundreds of buried drums within the LFLS, was placed within the trench. Dissolved neodymium nitrate was introduced as a point-source contaminant to the base of the trench, outside the steel drum. Hydrologic conditions were manipulated to simulate natural rainfall intensities with dissolved lithium bromide added as a tracer. Neodymium was primarily retained both at its point of release at the bottom of the trench (>97 %) as well as at a steel container corrosion point, simulated through the emplacement of steel wool. However, over the 8-month field experiment, advective mixing initiated by surface water intrusions rapidly redistributed a small proportion of Nd to shallower waters (~1.5-1.7 %), as well as throughout the buried steel drum. Suspended particulate forms of Nd (>0.2 µm) were measured at all depths in the suboxic trench and were persistent across the entire study. Analyses of the microbial communities showed that their relative abundances and metabolic functions were strongly influenced by the prevailing geochemical conditions as a result of fluctuating water depths associated with rainfall events. The site representing steel corrosion exhibited divergent biogeochemical results with anomalous changes (sharp decrease) observed in both dissolved contaminant concentration as well as microbial diversity and functionality. This research demonstrates that experimental trenches provide a safe and unique method for simulating the behaviour of subsurface radioactive contaminants with results demonstrating the initial retention, partial shallow water redistribution, and stability of particulate form(s) of this radioactive analogue. These results have relevance for appropriate management and remediation strategies for the adjacent legacy site as well as for similar sites across the globe.


Subject(s)
Plutonium , Radioactive Waste , Americium/analysis , Neodymium , Nitrates/analysis , Plutonium/analysis , Radioactive Waste/analysis , Radioisotopes/analysis , Steel , Water/analysis
20.
Radiat Prot Dosimetry ; 198(9-11): 586-589, 2022 Aug 22.
Article in English | MEDLINE | ID: mdl-36005964

ABSTRACT

YAP:Ce scintillation probe was tested for use in a spectrometric measurement that is necessary to assess the internal dose in case of wound injuries involving radionuclide contaminant. A technique with metal filters published in the past for the determination of a depth of plutonium-contaminated wound was tested to verify the capability of the scintillator to be used for gamma-ray spectrometry counting of 241Am in a wound injury. Scintillation probe equipped with YAP:Ce scintillator showed properties sufficient for the wound counting technique tested.


Subject(s)
Americium , Plutonium , Americium/analysis , Plutonium/analysis , Radioisotopes , Scintillation Counting/methods
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