Radioactive Contamination Research Articles

Li3[AlP2O7F(OH)](H2O)0.5 and A[Al2(PO4)2F(H2O)](A = K, Rb): Counter Cation Templates Derived Three Polar Alkaline Metal Fluoroaluminophosphates.

Three novel alkali metal fluoroaluminophosphates, Li3[AlP2O7F(OH)](H2O)0.5 and A[Al2(PO4)2F(H2O)](A = K, Rb), were designed and synthesized by using low-temperature flux methods. They crystallized in polar space groups P4 and P212121, respectively. Li3[AlP2O7F(OH)](H2O)0.5 features a unique two-dimensional layered structure of fluoroaluminophosphate [AlP2O7F(OH)]3-n, composed of alternately connected AlFO5 octahedra and PO4 tetrahedra. In contrast, with counter cations from Li+ to K+/Rb+, two new crystals of A[Al2(PO4)2F(H2O)](A = K, Rb) have been obtained. They possess a distinct three-dimensional anionic framework, [Al2(PO4)2F]-n, consisting of corner-sharing AlO5 triangular bipyramids, AlFO5 octahedra, and PO4 tetrahedra, revealing intersecting open tunnels along the [010], [001], and [111] directions. Notably, both Li3[AlP2O7F(OH)](H2O)0.5 and K[Al2(PO4)2F(H2O)] exhibit moderate second harmonic generation effects. Besides, porous material of K[Al2(PO4)2F(H2O)] exhibited remarkable ionic exchange properties with Cs+, implying its potential utility in the remediation of radioactive waste and offering a promising solution for managing nuclear contaminants. This research reports on their syntheses, topological structures, elemental analysis, thermal stability, IR Raman spectroscopy, UV-Vis diffuse reflectance spectroscopy, ion exchange property, and nonlinear optical characteristics.

Toward an usage of americium-241 for filter calibration

In nuclear safety and environmental studies, it is necessary to measure the activity of aerosols collected on filters. The calibration of these filters' measurement chains currently involves producing a reference filter with a controlled deposit of aerosol marked by a specific radionuclide. In France, commonly used radionuclides include 137Cs for gamma or beta emitters, 90Sr/90Y for beta emitters, and 239Pu for alpha emitters. However, using 239Pu presents several issues, notably the destruction of the filter required to determine its traceable activity and the associated uncertainties. The challenge of this project is to propose a radionuclide enabling non-destructive, SI-traceable measurement while retaining the reference filter. The proposed radionuclide is 241Am, which is both alpha and gamma-emitting and allows for precise non-destructive measurements. Reference filters are produced on the IRSN’s ICARE test bench with calibrated aerosols tagged with 241Am. The reference activity of theses filters is measured by gamma spectrometry on CEA/LNHB reference counter. A series of tests confirmed that 241Am provides accurate activity determination with minimal uncertainty. Consequently, adopting 241Am can significantly improve the reliability of radioactive contamination monitoring while avoiding practical challenges associated with plutonium.

Биосорбция техногенных радионуклидов баренцевоморской литоральной водорослью Fucus vesiculosus L.

The authors have conducted laboratory experiments to study the ability of the Barents Sea brown alga Fucus vesiculosus L. to adsorb technogenic radionuclides from seawater of various salinity (8, 18 and 35 psu). They have obtained new data on the role of macroalgae communities in the geodynamics of radionuclides in the coastal zone of the seas. Fucuses are able to adsorb 40—80% of the radionuclide activity from water. The maximum intensity of adsorption is observed during the first day of exposure. The alga most effectively absorbs 152Eu, 241Am, 65Zn, 54Mn from water. The possibility of using the alga as a sorbent in biobarriers in incidents with emergency discharges of radioactivity into the sea is shown.

Efficient capture and dual-model fluorescence detection of ReO4− using a TPE-based pyridinium network

99Technetium is one of the highly radioactive contaminants in nuclear wastewater. ReO4− is an ideal substitute for the safe handling of 99TcO4−, its efficient capture and detection are also significant for scarce rhenium resource recovery. However, designing novel materials for the efficient capture and detection of ReO4− and 99TcO4− is still very challenging. Herein, we establish dual-model fluorescence detection for ReO4− via quick ion exchange by a TPE-based cationic polymeric network (TPDC). TPDC displays good sensor performance for ReO4− accompanying the fluorescence enhancement as well as I− accompanying the fluorescence quenching (on-off). Interestingly, the quenched fluorescence can be reopened by ReO4− (off-on) with a slight increase in the detection limit. Moreover, the adsorption capacity for ReO4− reaches 804.2 mg g−1 and the adsorption equilibrium is achieved within 2 min with a kd value of 6.225×105 mL g−1. This work provides a multifunctional material that manifests efficient capture and dual-model fluorescence detection for ReO4− via quick ion exchange accompanying separate or continuous fluorescence change.

Ice cap functioned as a sink for radioactive contaminant in the Tibetan Plateau: evidence from plutonium isotopes

Ice cap functioned as a sink for radioactive contaminant in the Tibetan Plateau: evidence from plutonium isotopes

Investigation of the Transfer Radioactive Contamination from the Chernobyl Zone and its Impact on Radiation in the Environment

Investigation of the Transfer Radioactive Contamination from the Chernobyl Zone and its Impact on Radiation in the Environment

137Cs distribution in the system “agrochernozem clayey-illuvial – potato” in the area of radioactive contamination of the Tula region

The features of vertical distribution of 137Cs in the profile of clayeyilluvial agrochernozem, as well as biogenic migration of the radionuclide in the system “soil–plant” of potato agrocenosis have been studied. The research was conducted on the field, occupied by potato variety “Gala”, located in the central part of Plavsky radioactive hotspot of Tula region. It is shown that 35 years after the Chernobyl accident the density of surface radioactive contamination of arable soils in the region exceeds the permissible level by ≈5 times. The depth of 137Cs penetration down the soil profile is mainly determined by methods of agrotechnical soil treatment, and the main part of its inventories is concentrated in the upper 30-cm arable layer. This results in the direct contact of the radionuclide with underground organs of potato (roots, stolons and tubers). However, no more than 0.02% of the total 137Cs inventories contained in the system “agrochernozem–potato” is transferred to potato plants. It was also established that potato plants are characterized by contrasting distribution of 137Cs specific activity values wich varies with organs and tissues. Stolons and thin roots accumulate the radionuclide to the greatest extent per biomass, while tubers, on the contrary, – to the least extent. In general, the levels of 137Cs accumulation in the raw and dry weight of potato tubers, as well as in the products that have undergone culinary processing (boiling the unpeeled and peeled potatoes), correspond to sanitaryhygienic norms, which substantiates the low ecological risks of including potatoes in crop rotations on agricultural land in the area of the Plavsky radioactive hotspot of the Tula region.

Impact of Uncertainties of Nuclear Severe Accidents on Radiological and Nuclear Dispersion Predictions

Protection of the public as well as the environment is primal task of the regulators and provisions to sustain integrity of the plant have been developed. In addition to that, the consequences of possible severe accidents are necessary to develop strategies to mitigate the impact. Evaluation by using severe accident tools is common practice accepted by regulators, but these tools rely on models that generated by using limited experimental data. Thus, reliable evaluation of the accident also requires uncertainty quantification of the results. In this work, selected accident case on VVER-1000 is performed by using ASTEC tool and the uncertainties of the ASTEC code is quantified by using KATUSA tool with the goal of determination of the potential impact range. 100 samples are generated according to selected uncertain parameters, their probabilistic distribution functions (PDFs) and variation range, and multiple ASTEC code simulations are performed to evaluate the results. Finally, JRODOS calculation is performed on Zaporizhzhia NPP with worst-case and best-estimate scenarios to identify the difference on the radiological impact. The potential difference on the inventories results with almost two times higher radiological contamination of the selected area on selected period which causes almost 1.5 times higher doses on the population.

Diffusion coefficients calculations of 110mAg in ZrC at very high temperature using machine-learning interatomic potential

The ternary machine-learning interatomic potential for a Zr–C–Ag system was developed using first-principles calculations, moment tensor potential, and molecular dynamics simulations to calculate the diffusion coefficient of Ag in ZrC. The developed potential was utilized to investigate the vacancy formation energy, Ag substitutional energy, binding energy between Ag and vacancy, Ag interstitial energy, migration energy of Ag to an adjacent C vacancy in ZrC, and thermal expansion of ZrC. The results conformed to previously reported experimental and computational results, thereby validating the accuracy of the developed potential. The diffusion coefficients of Ag in ZrC0.94 and ZrC0.97 in the temperature range of 2800–3200 K were calculated using molecular dynamics simulations with the developed machine-learning interatomic potential. These calculation results can aid the safety analysis of radioactive 110mAg release in nuclear thermal propulsion reactors.

Assessment of the Level of Radioactivity in the Soil in Urban Areas and Building Materials of Arlit City (Agadez-NIGER)

Niger's uranium deposits are located in the north, bordering the southern Sahara. Mining activities led to the creation of the town of Arlit in 1969. Uranium mining and uranate production generate large volumes of radioactive solid and liquid tailings, as well as radioactive gases. Through dispersion and transport, these radioactive discharges become a source of contamination to the environment and food chain. The aim of our work is to assess the additional ambient exposure to radioactivity of surrounding populations as a result of mining activities. We assessed the risk of exposure to radionuclides from the uranium-238 decay chain through soil and certain building materials. The methodology used is based on collection of soil, sand, gravel and mud samples, which are analyzed using gamma spectrometry technique. Nine (9) public sites and five (5) building materials quarries were sampled for the work. The radiological parameters calculated are radium equivalent activity (Raeq), absorbed dose rate (D), internal and external risk indices (Hin and Hex) and gamma index (Iγ). For the whole study area, the calculated Raeq values range from 78.67 Bq/kg to 199.32 Bq/kg. These values are below the guideline value of 370 Bq/kg. In terms of air dose rate, however, the average value found was 0.32 mSv/year for the nine public sites considered. This exceeds the threshold value of 0.29 mSv/year corresponding to the selected exposure scenarios. In addition, in the mud (Quarry 5) and the second gravel quarry (Quarry 4), Iγ values greater than unity were found. A comparison is made with the results of similar studies around the world. Interpretation of the data obtained concludes that there is a risk of radiological overexposure at six (6) sites and two (2) quarries. This work is independent research which sheds new light on the issue of uranium mining activities impact on the environment in Arlit.

Enhancing safety: Multi-institutional FMEA and FTA on -based radio-pharmaceutical therapy.

This study investigates potential failure modes and conducts failure mode and effects analysis (FMEA) and fault tree analysis (FTA) on the administration of DOTATATE (LUTATHERA) and PSMA-617 (PLUVICTO). The quality management (QM) process in radiopharmaceutical therapies (RPTs) requires collaboration between nuclear medicine (NM) and radiation oncology (RO) departments. As part of a multi-institutional study, we surveyed various departments to identify and analyze failure modes, leading to a proposed comprehensive QM program. RPT teams in RO or NM clinics can benefit from this study by continually improving theirpractice. We reviewed the literature to investigate the administration of Pluvicto and Lutathera, focusing on prospective procedural failures and potential failure modes (PFMs) and their outcomes. We distributed an FMEA survey to multiple experienced centers in -based RPTs and calculated risk priority number (RPN) for various PFM. We conducted an FTA using this information to pinpoint the root causes of potentialfailures. The findings from the literature review and survey responses on the prospective study have identified several critical areas at risk of failure. These areas include non-optimized treatment delivery, inadequate patient monitoring, and lack of safety training, leading to radiation contamination from the dose excreted by the patients after treatment administration. A segmented FTA was created based on the FMEA results, focusing on radiation contamination with a high RPN value. By identifying the root causes of failures and proposing targeted improvements to the existing QM measures, this analysis enhances safety in treatment delivery of -based RPTs. Given the limited number of prospective risk analysis studies in RPTs, our research addresses the necessity for more such studies and recommends methods to apply this study to otherRPTs.

Species-specific trends of plutonium, radiocesium, and potassium-40 levels in three fish species of the Yenisei river (Siberia, Russia)

The Yenisei is the largest river in the Northern Hemisphere receiving controlled radioactive discharges from nuclear facilities. The paper presents a comparative study of temporal trends of artificial radionuclides plutonium (239,240Pu) and radiocesium (137Cs), and a natural isotope of the essential macronutrient potassium (40K) in samples of three commercial fish species (Northern pike, Baikal grayling, and Siberian dace) occupying different positions in a trophic network in the Yenisei River (Siberia, Russia). Samples of fish were caught in the Yenisei in 2011–2020 during a period of significant changes in controlled radioactive releases into the river. The study has shown no increase in plutonium concentration in fish samples within two years after the upsurge in controlled Pu discharge into the river (2018–2020). Average activity concentration of 239,240Pu (mBq∙kg−1 d.w., range, mean ± sd) in muscle of grayling (0.6–31.8, 10.9 ± 8.6) was higher (p < 0.01) than in muscle of dace (1.0–4.4, 2.4 ± 1.2) and pike (1.1–11, 3.8 ± 2.9). This can be attributed to the feeding of grayling on benthic invertebrates rich in Pu. The concentration of Pu tended to increase in muscle of pike with the increasing size of the fish. Average activity concentration of 137Cs (Bq∙kg−1 d.w., range, mean ± sd) in muscle of pike, a piscivorous fish (1.8–23.4, 7.7 ± 5.1), was significantly higher (p < 0.001) than the average activity concentration of 137Cs in muscle of dace (0.7–5.7, 2.7 ± 1.6) and grayling (1.3–7.2, 2.5 ± 1.7). A similar effect was revealed for 40K. This can be attributed to biomagnification of 137Cs and 40K in food chains. The results will draw a baseline for assessment of dose-dependent ecological risks for wild fish itself and fish consumers, add field-based facts to the fundamental knowledge of behavior of artificial radionuclides in freshwater food chains, and suggests a hypothesis for consequent experimental studies.

Enhanced decontamination of surface radioactive contamination using a hydrogel coating composited with Prussian blue

Enhanced decontamination of surface radioactive contamination using a hydrogel coating composited with Prussian blue

Specific consequences of using WMD: Radioactive contamination of foodstuffs and its potential health effects

Specific consequences of using WMD: Radioactive contamination of foodstuffs and its potential health effects

Investigation on the impact of the spatial arrangement of individuals in a standing-type in-vivo monitoring system

An automated standing type Quick Scan Whole Body Monitor (QS-WBM) has been developed for the measurement of internal radioactive contamination due to high energy photon (HEP) emitters (Eϒ >200 keV). Individuals are monitored while standing on a platform inside QS-WBM at specified reference position. Instances may occur where individuals deviate from their monitoring position, potentially leading to errors in the measurement of the body content. Positional inaccuracies are estimated in three potential scenarios: lateral displacement of the individual, movement perpendicular to the detector face, and forward bending of the torso. The Monte Carlo particle transport code FLUKA is used for estimation of efficiencies for selected radionuclides across various geometrical positions for adult male radiation workers. Approximately, 8% variation in calibration factors (CFs) is noted for lateral movements up to 15 cm from the centerline regardless of the energy, while perpendicular movements from reference position exhibit variations ranging from 14 to 60 %. This study helps in quantifying uncertainties in the estimation of body content and dose, arising from deviations in position of individuals in QS-WBM enclosure during monitoring.

An efficient Ni-based adsorbent for selective removal of 85Kr and 14CH4 in radioactive contaminants from nuclear process off-gas stream

Efficient adsorbents for radioactive gas treatment in nuclear energy cycle is crucial for eliminating negative environmental impacts caused by wide nuclear applications. A Ni-based MOF material called JUC-86(Ni) which is based on 1-H-benzimidazole-5-carboxylic acid (HBIC) linker was synthesized for adsorbing the 85Kr, 14CH4 from off-gas stream. It was disclosed that there is a suitable pore environment for 85Kr and 14CH4 preferred adsorption in JUC-86 and the adsorption capacity could even reach 2.79 mmol/g (85Kr) and 2.54 mmol/g (14CH4) which are almost higher than all the adsorbents. The 85Kr/N2 and 14CH4/N2 IAST selectivities of the resulting sample are satisfactory (11.63 and 9.43) and well matched with the breakthrough experiments where the breakthrough times of 85Kr and 14CH4 are much longer than N2. What’s more, the adsorption heats of 85Kr and 14CH4 are less than 30 kJ/mol which indicated a stronger affinity than N2 and a low-energy regeneration. As simulation results showed that the adsorption distribution follows a-spiral-pattern which could be attributed to the N atom in the CN, this is also the dominant factor of the 85Kr and 14CH4 preferable adsorption.

Highly effective fluorescence detection of UO22+ ions by an anionic Na/Eu heterometallic metal–organic framework with Lewis basic chelating sites

Uranium is a serious radioactive contaminant that can easily migrate into groundwater and surface water, posing a deadly threat to human health. Despite the development of various materials for detecting uranyl ions in water, rational design and synthesis of new uranium sensors with sensitivity, selectivity, and fast response remain challenging. Herein, we demonstrate a novel strategy for obtaining highly sensitive and selective UO22+ sensors by constructing heterometallic metal–organic framework with both an anionic skeleton and abundant chelating sites. Namely, the first anionic Na/Eu heterometallic metal–organic framework (Na/Eu-MOF) based UO22+ sensor is successfully synthesized by using sodium salt and europium salt as reactants, and abundant ether groups were introduced into its porous structure as chelating Lewis basic sites. Beneficial from the synergistic effect between the anionic skeleton and the chelating sites, Na/Eu-MOF achieved rapid, selective adsorption and fluorescence quenching toward uranyl ion. The detection limits of Na/Eu-MOF in deionized and lake water were determined to be 49.7 nM and 113.0 nM, respectively, which are lower than the maximum concentration of 130.0 nM in drinking water proposed by the United States Environmental Protection Agency, indicating potential environmental applications. The detection capability of Na/Eu-MOF is attributed to the combination system of energy competition and interactions between UO22+ ions and Na/Eu-MOF. This work offers a feasible strategy to construct an anionic heterometallic metal–organic framework with chelating sites for uranyl detection in an aqueous solution.

A modelling framework to analyze climate change effects on radionuclide aquifer contamination

Non-stationarity of climatic variables (e.g., temperature and precipitation) due to Climate Change (CC) can affect the migration processes of radionuclides released from nuclear activities. In this paper, a framework of analysis is developed to predict the evolution in time of contaminant concentration and fluence under different Climatic Boundary Conditions (CBCs) of precipitation scenarios provided by a climate model integrated with an accurate physical coupled hydraulic-transport model. A case study is worked out with respect to the migration of a radioactive contaminant (232Th) at Kirtland Air Force Base (Albuquerque, New Mexico, USA), for which the different CBCs considered are: i) stationary and ii) non-stationary precipitation. The effects of such alternative hypotheses on the physical modelling results are analysed, using a cross-wavelet analysis. It is shown that fluence is strongly affected by precipitation extremes, more than concentration, and it is claimed that a daily scale on the information and data of CBCs is necessary to model, with sufficient accuracy, the migration process and properly assess the impact of future CC on groundwater contamination.

New Practice of Environmental Governance in China

Abstract Preventive environmental civil public interest litigation is an institutional innovation of environmental governance in China. Previous research primarily focuses on the implementation of prevention principles and environmental risk management; however, it fails to identify the significant risks in the new practice. There are significant risks that human behaviour may result in the creation of radioactive toxins and contaminants that are not perceptible to humans and which may have dramatic short- or long-term effects on plants, animals, and humans. This paper seeks to close this research gap. A review of typical cases revealed three elements that judges should consider when identifying significant risks in preventive environmental public interest litigation. Firstly, the significant risks involved in the case must be directly related to the public interest. Secondly, the probability of significant risks occurring should be emphasised. Thirdly, the proportionality principle should be adhered to in deciding on preventive means to be used in the case. We found some ambiguities and defects in the identification of significant risks. This article makes proposals to improve environmental legislation and application ambiguities in new practice in order to contribute to better environmental governance.

ОГЛЯД РЕЗУЛЬТАТІВ ДОСЛІДЖЕНЬ ЗАБРУДНЕННЯ КАХОВСЬКОГО ВОДОСХОВИЩА ЦЕЗІЄМ-137 І СТРОНЦІЄМ-90, ЯКІ ПРОВОДИЛИСЬ ПІСЛЯ АВАРІЇ НА ЧОРНОБИЛЬСЬКІЙ АЕС (1986-1921 РР.)

The available data on the state of radioactive contamination of water and bottom sediments of the Kakhovka Reservoir were analyzed in order to assess the possible deterioration of the quality of the environment based on the indicators of radioactive contamination in the zone of influence of the emergency discharge of water due to destruction of the Kakhovka NPP dam by the Russian military. Contamination of the Kakhovka Reservoir with 137Cs occurred mainly through the fallouts of this radionuclide with aerosols on the water surface in May 1986. A much smaller part of this radionuclide transported by water runoff directly from the headwaters of the Dnieper basin. Strontium-90 entered the reservoir exclusively by water pathway starting from October 1986. The steady trends of decreasing activity of both radionuclides in water has been observed since 1987. Approximately to 1996 137Cs activity concentrations had decreased to pre-accident level, 90Sr activity demonstrated a slow decrease and by 2022 remained slightly higher than pre-accidental level. The average levels of contamination of the Kakhovka reservoir bottom with 137Cs and 90Sr turned out to be the lowest compared to the other reservoirs of the Dnieper cascade. It was shown that in 1994 137Cs activity levels were 0.06 Ci/km2(2,2 kBq/m2) on 80% of the bottom surface (submerged former floodplain of the Dnieper) and were lower than on the territory adjacent to the reservoir. In the areas of silt accumulation (former channel of the Dnieper) 137Cs activity was on average three times higher. Balance calculations based on the data of radiation monitoring of water showed that the amount of 137Cs activity in the bottom sediments in the period 1987-2022 halved due to natural radioactive decay, the amount of 90Sr activity decreased by approximately 20%, since activity losses due to natural radioactive decay were partially compensated by the constant supply of this radionuclide with water runoff from the contaminated part of the catchment. After a catastrophic water leak from the reservoir, the Dnieper floodplain had exposed. According to the calculations, the average density of soil contamination of the ехposed areas with 137Cs does not exceed 0.03 Ci/km2 (1,1 kBq/m2), with 90Sr – less than 0.1 Ci/km2 (3,7 kBq/m2). Silt deposits of the former Dnieper channel, which had an increased level of 137Cs contamination, were re-suspended, probably, and carried out into the Dnipro-Bug estuary and further into the Black Sea. However, according to our assumptions, this should not have a negative effect on the radioecological state of the sea, because the 137Cs activity concentrations in the water of north-western part of the Black Sea were always 20-30 times higher than in the Dnieper water.