Nuclear energy: Between global electricity demand, worldwide decarbonisation imperativeness, and planetary environmental implications

Quantum tunnelling effect in the cis-trans isomerization of uranyl tetrahydroxide

The role of quantum tunnelling (QT) in the proton transfer kinetics of the uranyl tetrahydroxide (UTH, [UO2(OH)4]2-) cis to trans isomerization was computationally studied under three possible reaction pathways. The first pathway involved a direct proton transfer from the hydroxide ligand to the oxo atom. In the other two pathways, one or two water molecules were added to the second sphere. The first H2O, bound by hydrogen bonds to the ligands, acts as a bridge enabling a proton shuttling, a concerted hopping of a proton from the hydroxide to the oxo atom similar to the Grotthuss mechanism. In the third pathway, the second water molecule does not participate in the H-transfer chain, but works as an anchor for the first water molecule, limiting its movement and therefore enhancing the QT. Since experimentally the reaction occurs in water, the first two pathways (no water or one H2O) serve only as models of the gas phase behaviour, while the third pathway will always be thermodynamically and kinetically preferred. The effects were investigated in the gas phase as well as in a continuum aqueous model, including the H/D Kinetic Isotope Effect (KIE). The results indicate that at very low temperatures, QT is the only mechanism that permits the reaction kinetics, consistent with the large computed KIE. At higher temperatures, thermally activated tunnelling competes with the classical crossing over the potential barrier.

N-formylmethionine-leucyl-phenylalanine protects against irradiation-induced damage to hematopoiesis and intestines

BACKGROUND

Ionizing radiation (IR), including radiotherapy, can exert lasting harm on living organisms. While liposaccharide (LPS) offers resistance to radiation damage, it also induces toxic responses. Thankfully, an LPS analogue called N-formylmethionine-leucyl-phenylalanine (fMLP) holds the potential to mitigate this toxicity, offering hope for radiation protection.

METHODS

Survival of C57BL/6 mice exposed to IR after administration with fMLP/LPS/WR-2721 or saline was recorded. Cell viability and apoptosis assay of bone marrow (BMC), spleen and small intestinal epithelial (HIECs) cells were tested by Cell Counting Kit-8 (CCK-8) and flow cytometry assay. Tissue damage was evaluated by Hematoxilin and Eosin (H&E), Ki-67, and TUNEL staining. RNA sequencing was performed to reveal potential mechanisms of fMLP-mediated radiation protection. Flow cytometry and western blot were performed to verify the radiation protection mechanism of fMLP on the cell cycle.

RESULTS

The survival rates of C57BL/6 mice exposed to ionizing radiation after administering fMLP increased. fMLP demonstrated low toxicity in vitro and in vivo, maintaining cell viability and mitigating radiation-induced apoptosis. Moreover, it protected against tissue damage in the hematopoietic and intestinal system. RNA sequencing shed light on fMLP's potential mechanism, suggesting its role in modulating innate immunity and cell cycling. This was evidenced by its ability to reverse radiation-induced G2/M phase arrests in HIECs.

CONCLUSION

fMLP serves as a promising radioprotective agent, preserving cells and radiosensitive tissues from IR. Through its influence on the cell cycle, particularly reversing radiation-induced arrest in G2/M phases, fMLP offers protection against IR's detrimental effects.

Organic Electrode Materials for Dual-Ion Batteries

Organic materials are widely used in various energy storage devices due to their renewable, environmental friendliness and adjustable structure. Dual-ion batteries (DIBs), which use organic materials as the electrodes, are an attractive alternative to conventional lithium-ion batteries for sustainable energy storage devices owing to the advantages of low cost, environmental friendliness, and high operating voltage. To date, various organic electrode materials have been applied in DIBs. In this review, we present the development of DIBs with a following brief introduction of characteristics and mechanisms of organic materials. The latest progress in the application of organic materials as anode and cathode materials for DIBs is mainly reviewed. Finally, we also discussed the challenges and prospects of organic electrode materials for DIBs.

Rheological and radioactive decontamination properties of ethyl cellulose sols in green solvents at a temperature below 0 °C

Strippable film decontamination has been considered one of the best prospects for radioactive surface decontamination due to its high decontamination effect and less secondary pollution. However, research into strippable films has until now focused on radioactive decontamination at room temperature. Therefore, it is vital to seek a suitable degradable material for preparing strippable films in removing contaminants in an extremely cold region, as it will face the problem of the freezing of the detergent. Ethyl cellulose (EC) is a kind of degradable biopolymer which is easily dissolved in volatile green organic solvents to form a sol below 0 °C which is advantageous for forming a film. Therefore, it would be the best choice for preparing a strippable film detergent. In this study, EC sols were obtained by placing EC powder into the green solvents anhydrous ethanol and ethyl acetate. The steady and dynamic rheological behavior of EC sols was investigated with a rotary rheometer with the temperature ranging from -10 °C to 0 °C to disclose their spraying performance. Moreover, the radioactive decontamination effect of EC sols and the mechanism were also investigated. The results showed that the EC sols were pseudoplastic fluids which obeyed the Ostwald-de Waele power law below 0 °C. Furthermore, the viscosity of EC sols could be reduced by stirring, which is convenient for large-area spraying during decontamination below 0 °C. At -10 °C, the comprehensive decontamination rates of all plates were over 85%. Therefore, EC sols could be used as a basic material for strippable film decontamination below 0 °C.

Exploring uranium bioaccumulation in the brown alga Ascophyllum nodosum: insights from multi-scale spectroscopy and imaging

Legacy radioactive waste can be defined as the radioactive waste produced during the infancy of the civil nuclear industry's development in the mid-20th Century, a time when, unfortunately, waste storage and treatment were not well planned. The marine environment is one of the environmental compartments worth studying in this regard because of legacy waste in specific locations of the seabed. Comprising nearly 70% of the earth's service, the oceans are the largest and indeed the final destination for contaminated fresh waters. For this reason, long-term studies of the accumulation biochemical mechanisms of metallic radionuclides in the marine ecosystem are required. In this context the brown algal compartment may be ecologically relevant because of forming large and dense algal beds in coastal areas and potential important biomass for contamination. This report presents the first step in the investigation of uranium (U, an element used in the nuclear cycle) bioaccumulation in the brown alga Ascophyllum nodosum using a multi-scale spectroscopic and imaging approach. Contamination of A. nodosum specimens in closed aquaria at 13 °C was performed with a defined quantity of U(VI) (10-5 M). The living algal uptake was quantified by ICP-MS and a localization study in the various algal compartments was carried out by combining electronic microscopy imaging (SEM), X-ray Absorption spectroscopy (XAS) and micro X-ray Florescence (μ-XRF). Data indicate that the brown alga is able to concentrate U(VI) by an active bioaccumulation mechanism, reaching an equilibrium state after 200 h of daily contamination. A comparison between living organisms and dry biomass confirms a stress-response process in the former, with an average bioaccumulation factor (BAF) of 10 ± 2 for living specimens (90% lower compared to dry biomass, 142 ± 5). Also, these results open new perspectives for a potential use of A. nodosum dry biomass as uranium biosorbent. The different partial BAFs (bioaccumulation factors) range from 3 (for thallus) to 49 (for receptacles) leading to a compartmentalization of uranium within the seaweed. This reveals a higher accumulation capacity in the receptacles, the algal reproductive parts. SEM images highlight the different tissue distributions among the compartments with a superficial absorption in the thallus and lateral branches and several hotspots in the oospheres of the female individuals. A preliminary speciation XAS analysis identified a distinct U speciation in the gametes-containing receptacles as a pseudo-autunite phosphate phase. Similarly, XAS measurements on the lateral branches (XANES) were not conclusive with regards to the occurrence of an alginate-U complex in these tissues. Nonetheless, the hypothesis that alginate may play a role in the speciation of U in the algal thallus tissues is still under consideration.

Meta-analysis of the thermal pollution caused by coastal nuclear power plants and its effects on marine biodiversity

The rise in seawater temperature due to industrial activities is one of the main threats to marine biodiversity. In nuclear power plants, large volumes of water are used for their operation, returning to the ecosystem at higher temperatures. A global meta-analysis was performed to evaluate the thermal effects caused by coastal nuclear power plants on marine organisms. We found 853 articles of which, 99 were included in the qualitative analysis and 75 in the meta-analysis. The meta-analysis showed an increase of 4.38 °C in water temperature near the outfall, and the temperature variation of each study was found to be associated with the power plant latitudes. The main effects on organisms were related to changes in the structure and composition of aquatic communities, with species abundance, distribution, dominance, and density being the most cited ones. Among the affected groups, photosynthesizing microorganisms were the most cited, potentially contributing to shifts in ecosystem dynamics.

Proposed solutions to anthropogenic climate change: A systematic literature review and a new way forward

Humanity is now facing what may be the biggest challenge to its existence: irreversible climate change brought about by human activity. Our planet is in a state of emergency, and we only have a short window of time (7-8 years) to enact meaningful change. The goal of this systematic literature review is to summarize the peer-reviewed literature on proposed solutions to climate change in the last 20 years (2002-2022), and to propose a framework for a unified approach to solving this climate change crisis. Solutions reviewed include a transition toward use of renewable energy resources, reduced energy consumption, rethinking the global transport sector, and nature-based solutions. This review highlights one of the most important but overlooked pieces in the puzzle of solving the climate change problem - the gradual shift to a plant-based diet and global phaseout of factory (industrialized animal) farming, the most damaging and prolific form of animal agriculture. The gradual global phaseout of industrialized animal farming can be achieved by increasingly replacing animal meat and other animal products with plant-based products, ending government subsidies for animal-based meat, dairy, and eggs, and initiating taxes on such products. Failure to act will ultimately result in a scenario of irreversible climate change with widespread famine and disease, global devastation, climate refugees, and warfare. We therefore suggest an "All Life" approach, invoking the interconnectedness of all life forms on our planet. The logistics for achieving this include a global standardization of Environmental, Social, and Governance (ESG) or similar measures and the introduction of a regulatory body for verification of such measures. These approaches will help deliver environmental and sustainability benefits for our planet far beyond an immediate reduction in global warming.

The effect of fission products Xe and Cs on the thermal conductivity of the U3Si2lattice: a first-principles study

In the past decades, uranium silicide (U3Si2) as a promising accident tolerant fuel (ATF) has drawn considerable attention in the field of nuclear physics. In comparison with traditional nuclear fuel (UO2), the U3Si2has higher thermal conductivity and uranium density, thereby resulting in lower centerline temperatures and better fuel economy. However, during the nuclear fission reaction, some unexpected fission products, such as Xe and Cs, are released and form the defective states. In this study, we explore the influence of Xe and Cs on the thermal conductivity of the U3Si2lattice from 200 to 1500 K using density functional theory calculations combined with Boltzmann transport equation. Our results reveal that the lattice and electronic thermal conductivities of defective U3Si2are reduced at a constant temperature, as compared with that of ideal system, thus resulting in a decrease of the total thermal conductivity. In the case of Cs occupation at U1 site, the total thermal conductivity (4.42 W mK-1) is decreased by ∼56% at 300 K, as compared with the value of 9.99 W mK-1for ideal system. With U1 and Si sites being occupied by Xe, the total thermal conductivities (4.45 and 6.52 W mK-1) are decreased by ∼55% and 35% at 300 K, respectively. The presented results suggest that the U3Si2has potential as a promising ATF at high temperatures.

Viologen-functionalized magnetic material for the removal of Iodine and benzanthracene in an aqueous solution

The development of magnetically active adsorbents for effective iodine removal would be highly desirable to address environmental pollution and remediation. Herein, we demonstrated the synthesis of Vio@SiO₂@Fe₃O₄ as an adsorbent via surface functionalisation of electron-deficient bipyridium (viologen) units on the surface of magnetically active silica-coated magnetite (Fe₃O₄) core. This adsorbent was characterised thoroughly using various analytical techniques, such as field emission scanning electron microscopy (FESEM), thermal gravimetric analysis, Fourier transform infrared spectroscopy (FTIR), field emission transmission electron microscopy (FETEM), Brunauer-Emmett-Teller (BET) analysis and X-ray photon analysis (XPS). The removal of triiodide from the aqueous solution was monitored via the batch method. It revealed that the complete removal was achieved upon stirring for 70 min. The thermally stable and crystalline Vio@SiO₂@Fe₃O₄ displayed efficient removal capacity even in the presence of other competing ions and at different pHs. The adsorption kinetics data were analysed following the pseudo-first-order and pseudo-second-order models. Further, the isotherm experiment showed that the maximum uptake capacity of iodine is 1.38 g/g. It can be regenerated and reused over multiple cycles to capture iodine. Further, Vio@SiO₂@Fe₃O₄ displayed a good removal capacity toward toxic polyaromatic, Benzanthracene (BzA) pollutant with an uptake capacity of 2445 μg/g. This effective removal of toxic pollutants iodine/benzanthracene was attributed to the strong non-covalent electrostatic and π-π interaction with electron-deficient bipyridium units.

Impact of microbial processes on the safety of deep geological repositories for radioactive waste

To date, the increasing production of radioactive waste due to the extensive use of nuclear power is becoming a global environmental concern for society. For this reason, many countries have been considering the use of deep geological repositories (DGRs) for the safe disposal of this waste in the near future. Several DGR designs have been chemically, physically, and geologically well characterized. However, less is known about the influence of microbial processes for the safety of these disposal systems. The existence of microorganisms in many materials selected for their use as barriers for DGRs, including clay, cementitious materials, or crystalline rocks (e.g., granites), has previously been reported. The role that microbial processes could play in the metal corrosion of canisters containing radioactive waste, the transformation of clay minerals, gas production, and the mobility of the radionuclides characteristic of such residues is well known. Among the radionuclides present in radioactive waste, selenium (Se), uranium (U), and curium (Cm) are of great interest. Se and Cm are common components of the spent nuclear fuel residues, mainly as 79Se isotope (half-life 3.27 × 105 years), 247Cm (half-life: 1.6 × 107 years) and 248Cm (half-life: 3.5 × 106 years) isotopes, respectively. This review presents an up-to-date overview about how microbes occurring in the surroundings of a DGR may influence their safety, with a particular focus on the radionuclide-microbial interactions. Consequently, this paper will provide an exhaustive understanding about the influence of microorganisms in the safety of planned radioactive waste repositories, which in turn might improve their implementation and efficiency.

Nanoprecipitates to Enhance Radiation Tolerance in High-Entropy Alloys

The growth of advanced energy technologies for power generation is enabled by the design, development, and integration of structural materials that can withstand extreme environments, such as high temperatures, radiation damage, and corrosion. High-entropy alloys (HEAs) are a class of structural materials in which suitable chemical elements in four or more numbers are mixed to typically produce single-phase concentrated solid solution alloys (CSAs). Many of these alloys exhibit good radiation tolerance like limited void swelling and hardening up to relatively medium radiation doses (tens of displacements per atom (dpa)); however, at higher radiation damage levels (>50 dpa), some HEAs suffer from considerable void swelling limiting their near-term acceptance for advanced nuclear reactor concepts. In this study, we developed a HEA containing a high density of Cu-rich nanoprecipitates distributed in the HEA matrix. The Cu-added HEA, NiCoFeCrCu_0.12, shows excellent void swelling resistance and negligible radiation-induced hardening upon irradiation up to high radiation doses (i.e., higher than 100 dpa). The void swelling resistance of the alloy is measured to be significantly better than NiCoFeCr CSA and austenitic stainless steels. Density functional theory simulations predict lower vacancy and interstitial formation energies at the coherent interfaces between Cu-rich nanoprecipitates and the HEA matrix. The alloy maintained a high sink strength achieved via nanoprecipitates and the coherent interface with the matrix at a high radiation dose (∼50 dpa). From our experiments and simulations, the effective recombination of radiation-produced vacancies and interstitials at the coherent interfaces of the nanoprecipitates is suggested to be the critical mechanism responsible for the radiation tolerance of the alloy. The materials design strategy based on incorporating a high density of interfaces can be applied to high-entropy alloy systems to improve their radiation tolerance.

The Predictors of Unsafe Behaviors among Nuclear Power Plant Workers: An Investigation Integrating Personality, Cognitive and Attitudinal Factors

Unsafe behaviors, such as violations and human errors, have long been recognized as the main causes of accidents in nuclear power plants (NPPs). However, personal factors that influence unsafe behaviors among NPP workers have not been well examined, especially in an integrated model. This study proposes an integrated contextual mediated model to examine personality, cognitive and attitudinal predictors of unsafe behaviors among commissioning workers at NPPs. The model was verified using structural equation modeling technique with survey data from 177 commissioning workers in two Chinese NPPs. Results show that personality traits (i.e., conscientiousness, neuroticism, openness and agreeableness), executive function and safety attitudes exerted significant effects on unsafe behaviors. In addition, the effects of agreeableness and executive function were partly mediated by safety attitudes. Both conscientiousness and neuroticism indirectly influenced unsafe behaviors through the mediating role of executive function. The findings shed light on the design of evidence-based interventions for safety performance in NPPs.

Tetrabromobisphenol a exacerbates the overall radioactive hazard to zebrafish (Danio rerio)

The major health risks of dual exposure to two hazardous factors of plastics and radioactive contamination are obscure. In the present study, we systematically evaluated the combinational toxic effects of tetrabromobisphenol A (TBBPA), one of the most influential plastic ingredients, mainly from electronic wastes, and γ-irradiation in zebrafish for the first time. TBBPA (0.25 μg/mL for embryos and larvae, 300 μg/L for adults) contamination aggravated the radiation (6 Gy for embryos and larvae, 20 Gy for adults)-induced early dysplasia and aberrant angiogenesis of embryos, further impaired the locomotor vitality of irradiated larvae, and worsened the radioactive multiorganic histologic injury, neurobehavioural disturbances and dysgenesis of zebrafish adults as well as the inter-generational neurotoxicity in offspring. TBBPA exaggerated the radiative toxic effects not only by enhancing the inflammatory and apoptotic response but also by further unbalancing the endocrine system and disrupting the underlying gene expression profiles. In conclusion, TBBPA exacerbates radiation-induced injury in zebrafish, including embryos, larvae, adults and even the next generation. Our findings provide new insights into the toxicology of TBBPA and γ-irradiation, shedding light on the severity of cocontamination of MP components and radioactive substances and thereby inspiring novel remediation and rehabilitation strategies for radiation-injured aqueous organisms and radiotherapy patients.

Integrating water science, economics, and policy for future climate adaptation

Water science, water economics, and water policy issues continue to rise in importance internationally as elevated population, income growth, and climate change magnify scarcity, shortages, and injustices in water access. Based on the unique physical, institutional, and economic characteristics of water, this work's first contribution is to characterize a road forward for research innovations that enable better integration of water science, water economics, and water policy. Meeting water's sustainable development and justice goals calls for several research innovations that humanity awaits. The advances called for in this work include deep uncertainty management, red team reviews, innovative water rights design, accelerating SDG achievement, valuing water infrastructure, valuing natural water retention, incentivizing water conservation, improving financial performance of rural water systems, water network modularization, non-price scarcity signals, optimization model calibration, remote sensing, transboundary benefit sharing, optimal growth, and water valuation. The work's second contribution is to present a prototype scalable basin scale hydroeconomic analysis (HEA) as a framework for integrating these above innovations when they occur. Results of the HEA show that losses from a 50% shortage in the basin's surface water supply can continue to protect 93% of total economic benefits across economic sectors if an efficient water trading system is established to move water from lower to higher valued uses when shortages occur. The work concludes by noting that great advances remain needed for better and longer lives.

Nuclear Radiation Knowledge and Anxiety Levels among Residents around a Nuclear Power Plant in Liaoning Province, China

Awareness of radiation-related knowledge (RRK) and nuclear energy-related knowledge (NERK) among residents around a nuclear power plant (NPP), as well as their concerns about a NPP, were investigated. A face-to-face survey was conducted among 1,775 residents within 30 km around the NPP in Liaoning Province, China. A single-item Likert scale, Spearman's/Pearson's correlation coefficients, Student's t-test, ANOVA, and multiple-linear regression analysis were employed. Awareness of RRK and NERK among residents around the NPP was 27.7% and 36.6%, respectively. The anxiety level of respondents was negatively corelated with the distance from their residence to the NPP and age. Also, 55.6% of respondents thought that the publicity about nuclear energy/NPPs was insufficient, and 82.7% of respondents wanted to know relevant information about NPPs. Awareness of RRK and NERK among residents around the NPP was relatively low, which was related to education, occupation, and income. The anxiety level among residents was related to distance and age. The public was eager to know about RRK and NERK. These findings indicate that the publicity and education of RRK and NERK among residents around the NPP should be strengthened.

Comprehensive Review on Zeolite-Based Nanocomposites for Treatment of Effluents from Wastewater

All humans and animals need access to clean water in their daily lives. Unfortunately, we are facing water scarcity in several places around the world, and, intentionally or unintentionally, we are contaminating the water in a number of ways. The rise in population, globalization, and industrialization has simultaneously given rise to the generation of wastewater. The pollutants in wastewater, such as organic contaminants, heavy metals, agrochemicals, radioactive pollutants, etc., can cause various ailments as well as environmental damage. In addition to the existing pollutants, a number of new pollutants are now being produced by developing industries. To address this issue, we require some emerging tools and materials to remove effluents from wastewater. Zeolites are the porous aluminosilicates that have been used for the effective pollutant removal for a long time owing to their extraordinary adsorption and ion-exchange properties, which make them available for the removal of a variety of contaminants. However, zeolite alone shows much less photocatalytic efficiency, therefore, different photoactive materials are being doped with zeolites to enhance their photocatalytic efficiency. The fabrication of zeolite-based composites is emerging due to their powerful results as adsorbents, ion-exchangers, and additional benefits as good photocatalysts. This review highlights the types, synthesis and removal mechanisms of zeolite-based materials for wastewater treatment with the basic knowledge about zeolites and wastewater along with the research gaps, which gives a quality background of worldwide research on this topic for future developments.

A Study of Sr Sorption Behavior in Claystone from a Candidate High-Level Radioactive Waste Geological Disposal Site under the Action of FeOOH Colloids

Colloids have a significant influence on the migration of nuclides in claystone, which is an important geological barrier. The sorption of strontium on claystone in the presence of FeOOH colloids was investigated in samples from the Suhongtu site, a candidate high-level radioactive waste disposal site in China. The effects of colloid amount, solid content, and pH were investigated by batch tests, and the sorption reaction mechanism was analyzed by kinetic modeling and microscopic characterization techniques. The results indicate that the sorption of Sr by claystone increased with the solids content, and the claystone had a stronger Sr sorption capacity under alkaline conditions. The Sr sorption kinetics were best described by the pseudo-first-order and pseudo-second-order models, which revealed that the progress is affected by physical diffusion and chemical sorption. Furthermore, the microscopic characterization results demonstrate that cation exchange reactions and surface complex reactions are the main sorption mechanisms for Sr sorption on claystone. Ca and Mg plasmas in claystone minerals can have cation replacement reactions with Sr, and functional groups such as -OH and [CO₃]^2- can have complexation reactions with Sr to adsorb Sr on the surface of the claystone. Additionally, the presence of the FeOOH colloid inhibited the sorption effect of claystone slightly. The FeOOH colloid could occupy sorption sites on the claystone surface, which reduces the activity of the functional groups and inhibits the sorption of Sr on claystone.

NaOH-assisted H2O2 post-modification as a novel approach to enhance adsorption capacity of residual coffee waste biochars toward radioactive strontium: Experimental and theoretical studies

In this study, NaOH-assisted H₂O₂ post-modification was proposed as a novel strategy to enhance the adsorption of radioactive strontium (Sr) onto residual coffee waste biochars (RCWBs). To validate its viability, the adsorption capacities and mechanisms of Sr(II) using pristine (RCWB_P), H₂O₂ post-modified (RCWB_HP), and NaOH-assisted H₂O₂ post-modified residual coffee waste biochars (RCWB_NHP) were experimentally and theoretically investigated. The highest adsorption capacity of Sr(II) for RCWB_NHP (10.91 mg/g) compared to RCWB_HP (5.57 mg/g) and RCWB_P (5.07 mg/g) was primarily attributed to higher negative surface zeta potential (RCWB_NHP = -5.66 → -30.97 mV; RCWB_HP = -0.31 → -11.29 mV; RCWB_P = 1.90 → -10.40 mV) and decoration of Na on the surfaces of RCWB_P via NaOH-assisted H₂O₂ post-modification. These findings agree entirely with the theoretical observations that the adsorption of Sr(II) onto RCWB_P and RCWB_HP was controlled by electrostatic interactions involving carbonyls whereas enriched carboxylic acids and decorated Na on the surfaces of RCWB_NHP through the replacement of Mg and K by NaOH-assisted H₂O₂ modification stimulated electrostatic interactions and cation exchanges governing the adsorption of Sr(II). Hence, NaOH-assisted H₂O₂ post-modification seemed to be practically applicable for improving the adsorption capacity of Sr(II) using RCWB-based carbonaceous adsorbents in real water matrices.

Pyridine-di-phosphonates as chelators for trivalent f-elements: kinetics, thermodynamic and interfacial study of Am(III)/Eu(III) solvent extraction

The fractionation of high-level radioactive waste from nuclear power plants simplifies the handling of its components, and facilitates the reduction of radiotoxic effects on the environment. The search and study of new ligands for solvent extraction, as one of the methods in fractionation, remains a complex and important research task. In this work, four pyridine diphosphonate ligands were synthesized. These ligands are part of the class of the N,O-donor extractants, which are selective towards Am(III). The separation factor SF(Am/Eu) for the best extractant reached values up to 10. The influence of the substituents on the efficiency of extraction and complexation of trivalent f-elements, the kinetics of extraction, and the behavior of the ligand at the interface were described. The effect of nitric acid concentration on the extraction was shown. The stoichiometry of the complexes was determined by slope analysis in solvent extraction experiment and verified by spectrophotometric titration in acetonitrile. Liquid tension experiments with a pendant drop method revealed the interfacial properties of the ligands in "F-3 solvent/H₂O" and "F-3 solvent/HNO₃" systems. The relationship between the surface activity and the ligand structure was shown. Studies of the extraction kinetics were performed in a modified Lewis cell. The effect of the ligand structure on the extraction rate was shown. The DFT calculation with the B3LYP density functional was used to explain the extraction properties of the ligands, including selectivity. The calculation of the pre-organization energy of the ligands explained the kinetics and extraction patterns for the studied series.

Nuclear energy transition and CO2 emissions nexus in 28 nuclear electricity-producing countries with different income levels

Background

Nuclear energy carries the least environmental effects compared to fossil fuels and most other renewable energy sources. Therefore, nuclear energy transition (NET) would reduce pollution emissions. The present study investigates the role of the NET on CO₂ emissions and tests the environmental Kuznets curve (EKC) in the 28 nuclear electricity-producing countries from 1996-2019.

Methods

Along with a focus on the whole panel, countries are divided into three income groups using the World Bank classification, i.e., three Lower-Middle-Income (LMI), eight Upper-Middle-Income (UMI), and 17 High-Income (HI) countries. The cross-sectional dependence panel data estimation techniques are applied for the long and short run analyses.

Results

In the long run, the EKC is corroborated in HI countries' panel with estimated positive and negative coefficients of economic growth and its square variable. The Netherlands, Sweden, Switzerland, and the USA are found in the 2^nd stage of the EKC. However, the remaining HI economies are facing 1^st phase of the EKC. Moreover, economic growth has a monotonic positive effect on CO₂ emissions in LMI and UMI economies. NET reduces CO₂ emissions in UMI and HI economies. On the other hand, NET has an insignificant effect on CO₂ emissions in LMI economies. In the short run, the EKC is validated and NET has a negative effect on CO₂ emissions in HI countries and the whole panel. However, NET could not affect CO₂ emissions in LMI and UMI countries. Based on the long-run results, we recommend enhancing nuclear energy transition in UMI and HI economies to reduce CO₂ emissions. In addition, the rest of the world should also build capacity for the nuclear energy transition to save the world from global warming.

Characteristics and Influencing Factors of Polycyclic Aromatic Hydrocarbons Emitted from Open Burning and Stove Burning of Biomass: A Brief Review

To mitigate global warming and achieve carbon neutrality, biomass has become a widely used carbon-neutral energy source due to its low cost and easy availability. However, the incomplete combustion of biomass can produce polycyclic aromatic hydrocarbons (PAHs), which are harmful to human health. Moreover, increasing numbers of wildfires in many regions caused by global warming have greatly increased the emissions of PAHs from biomass burning. To effectively mitigate PAH pollution and health risks associated with biomass usage, the concentrations, compositions and influencing factors of PAH emissions from biomass burning are summarized in this review. High PAH emissions from open burning and stove burning are found, and two- to four-ring PAHs account for a higher proportion than five- and six-ring PAHs. Based on the mechanism of biomass burning, biomass with higher volatile matter, cellulose, lignin, potassium salts and moisture produces more PAHs. Moreover, burning biomass in stoves at a high temperature or with an insufficient oxygen supply can increase PAH emissions. Therefore, the formation and emission of PAHs can be reduced by pelletizing, briquetting or carbonizing biomass to increase its density and burning efficiency. This review contributes to a comprehensive understanding of PAH pollution from biomass burning, providing prospective insight for preventing air pollution and health hazards associated with carbon neutrality.

2-Methylpyrrolidine derived 1,10-phenanthroline-2,9-diamides: promising extractants for Am(iii)/Ln(iii) separation

In this work we report on new examples of phenanthrolindiamides containing asymmetric centers in amide substituents.

Gamma-Ray Protection Properties of Bismuth-Silicate Glasses against Some Diagnostic Nuclear Medicine Radioisotopes: A Comprehensive Study

This study aimed to perform an investigation for the potential implementation of bismuth silicate glasses as novel shield equipment instead of ordinary shields in nuclear medicine facilities. Accordingly, a group of Bi₂O₃ reinforced silicate glass system were investigated and compared with ordinary shields in terms of their gamma-ray attenuation properties in diagnostic nuclear medicine radioisotope energies emitted from ^99mTc, ¹¹¹In, ⁶⁷Ga, ¹²³I, ¹³¹I, ^81mKr, ²⁰¹Tl, ¹³³Xe. Mass attenuation coefficient (μm) results for glass samples were calculated comparatively with the XCOM program and MCNPX code. The gamma-ray attenuation parameters such as half value layer (HVL), tenth value layer (TVL), mean free path (MFP), effective atomic number (Z_eff) were obtained in the diagnostic gamma ray energy range from 75 to 336 keV. To confirm the attenuation performance of superior sample, obtained results were extensively compared with ordinary shielding materials. According to the results obtained, BISI6 glass sample with the highest Bi₂O₃ additive has an excellent gamma-ray protection.

Changes in adsorption mechanisms of radioactive barium, cobalt, and strontium ions using spent coffee waste biochars via alkaline chemical activation: Enrichment effects of O-containing functional groups

The single adsorption of radioactive barium (Ba(II)), cobalt (Co(II)), and strontium (Sr(II)) ions using pristine (SCWB-P) and chemically activated spent coffee waste biochars with NaOH (SCWB-A) were thoroughly explored in order to provide deeper insights into the changes in their adsorption mechanisms through alkaline chemical activation. The greater removal efficiencies of SCWB-A (76.6-97.3%) than SCWB-P (45.6-75.2%) and the consistency between the adsorptive removal patterns (Ba(II) > Sr(II) > Co(II)) and oxygen bond dissociation enthalpies (BaO (562 kJ/mol) > SrO (426 kJ/mol) > CoO (397 kJ/mol)) of radioactive species supported the assumption that the adsorption removal of radioactive species with spent coffee waste biochars highly depended on the abundances of O-containing functional groups. The calculated R² values of the pseudo-first-order (SCWB-P = 0.998-0.999; SCWB-A = 0.850-0.921) and pseudo-second-order kinetic models (SCWB-P = 0.988-0.998; SCWB-A = 0.935-0.966) are evident that the physisorption mainly controlled the adsorption of radioactive species toward SCWB-P and the chemisorption played a crucial role in their adsorptive removal with SCWB-A. From the calculated intra-particle diffusion, isotherm, thermodynamic parameters, it can be concluded that the intra-particle diffusion and monolayer adsorption primarily governed the adsorption of radioactive species using SCWB-P and SCWB-A, and their adsorption processes occurred spontaneously and endothermically. The dominant adsorption mechanism of spent coffee waste biochars was changed from physisorption (ΔH° of SCWB-P = 21.6-29.8 kJ/mol) to chemisorption (ΔH° of SCWB-A = 42.4-81.3 kJ/mol) through alkaline chemical activation. The distinctive M-OH peak in the O1s XPS spectra of SCWB-A directly corresponding to the decrease in the abundances of O-containing functional groups confirms again that the enrichment of O-containing functional groups markedly facilitated the adsorption removal of radioactive species by chemisorption occurred at the inner and outer surfaces of spent coffee waste biochars.

A review of the alpha radiolysis of extractants for actinide lanthanide separation in spent nuclear fuel reprocessing

Radiation stability is one of the key properties to enable the efficient use of extractants in spent nuclear fuel with high radioactivity. The last several decades have witnessed a rapid progress in the radiation chemistry of extractants. A variety of studies and reviews pertinent to the radiation stability of extractants have been published. However, a thorough summary for the alpha radiolysis results of extractants is not available. In this review, we survey the development of alpha radiolysis of extractants for actinide lanthanide separation and compare their radiolysis behaviors induced by alpha particles and gamma rays. The discussion of alpha radiolysis of extractants is divided into three parts according to the functional groups of extractants (i.e., phosphine oxide, amide and bis-triazinyl bipyridines). Given the importance of radiation source to carry out alpha irradiation experiment, we first give a brief introduction to three practicable alpha radiation sources including alpha emitting isotopes, helium ion beam and reactor. We hope this review will provide useful information and unleash a broad palette of opportunities for researchers interested in radiation chemistry.

Progress in nuclear energy with carbon pricing to achieve environmental sustainability agenda: on the edge of one's seat

The Paris agreement (COP21) emphasized the need to progress toward using low-carbon energy technologies, including nuclear power, that is favorably looked for to meet the challenges to reduce an enormous increase in global temperature to below 2 °C. The cost of carbon pollution is highly induced by the energy sector that damages the global environmental sustainability plan. The alternative and nuclear energy demand is an optimized solution to decrease carbon damages, which can be better work under the imposition of carbon taxes on polluting industries. This study works in a given direction to analyze the role of alternative and nuclear energy, carbon pricing, FDI inflows, fossil fuel combustion, economic growth, and population density on the cost of carbon pollution in a panel of 90 selected countries for a period of 1995-2018. The results confirmed a "nuclear energy-augmented environmental Kuznets curve" with a turning point of 39.974% of total energy demand across countries. The result implies that alternative and nuclear energy initially increases carbon damages. Simultaneously, it decreases at the later stages of atomic energy expansion; thus, nuclear power growth is imperative for long-term sustainable development. A positive relationship is found between carbon pricing and carbon damage, while a negative relationship is between fossil fuel combustion and carbon damage across countries. The results conclude that expansion in nuclear energy would help reduce the cost of carbon pollution to achieve environmental sustainability agenda across countries.

The Use of Hierarchical Agglomeration Methods in Assessing the Polish Energy Market

Energy markets play an important role in achieving sustainable development goals. The sector of energy has a huge impact on the environment, hence changes in it are the highest priority in the European Union. The process of shaping and developing the internal energy market plays an important role in improving the security of supply of energy resources for the entire union. It requires a number of political negotiations, strategic decisions regarding energy liberalization, in particular, the electricity and gas sectors, as well as the adoption of sectoral legislation. The aim of the conducted research is to estimate the level of development of energy markets in the EU countries and to indicate the position of Poland in comparison to other countries. The research was performed in several stages. The first phase consisted of selecting appropriate diagnostic variables that comprehensively describe energy markets in countries belonging to the European Union. The next stage was collecting data, subjecting them to standardization, and then, based on the agglomeration algorithm, the process of dividing into groups of similar countries was carried out. The research results can be used as guidelines for legal regulations being prepared in the energy sectors of all member states, which can be used for selected clusters comprising similar countries in terms of the development of energy markets.

Bioinspired Construction of Uranium Ion Trap with Abundant Phosphate Functional Groups

Highly efficient extraction of radioactive uranium from aqueous solution remains a serious task in the nuclear energy field. To address this, we here create an effective uranium ion trap by using a novel and facile strategy that introduces bioinspired moiety phytic acid (PA) into highly robust PCN-222. The resultant metal-organic framework (MOF)-based uranium ion trap (PCN-222-PA) with a high density of accessible phosphate groups exhibits a remarkable U(VI) uptake capacity (401.6 mg·g^-1), surpassing most of the reported phosphorus-modified MOFs and various other MOF adsorbents. Kinetics study reveals that PCN-222-PA can reduce the uranium concentration from 10 mg L^-1 to 21 μg L^-1, below the acceptable limit defined by the US Environmental Protection Agency. In addition, PCN-222-PA also shows good selectivity and high stability as well as excellent recyclability toward uranium capture. Our work demonstrates a new strategy to design functional MOFs with abundant phosphate groups and provides a new perspective for extracting uranium from aqueous solution.

The impact of gamma-irradiation from radioactive liquid wastewater on polymeric structures of nanofiltration (NF) membranes

In this study, the impacts of gamma-irradiation from the low- and intermediate-level liquid radioactive wastewaters (LILW) to polyamide (PA) structures of nanofiltration (NF) membranes were investigated. As the gamma-irradiation increased to 300 kGy in the aqueous solution at 5 bar, both the salt rejection and the water permeability of NF membranes were decreased from 95.6 ± 0.1%-74.6 ± 0.5%, and from 33.7 ± 0.3 LMH to 21.4 ± 0.5 LMH, respectively. The surface free energy and Young's modulus of the membrane indicated the decrease in hydrophilicity and the increase in fragility of PA structure after gamma-irradiation. X-ray photoelectron spectroscopy and the streaming potential analysis exhibited that the gamma-irradiation resulted the increase in the cross-linked portion of the amide bonding from 28% to 45% due to the gamma-induced new bonding between unbound carboxylic groups and amine groups. Nuclear magnetic resonance analysis confirmed that the poly(p-phenylene) in polyamide structure were changed to poly(cyclohexane) and poly(cyclohexene) by hydrogen radical disproportionation generated from the gamma-irradiated water, and it is responsible to the increase of the cross-linked PA structures. The decrease in salt rejection and water permeability is attributed to the aging of PA structures by gamma-irradiation, thus, should be carefully monitored during the treatment of LILW using NF membrane processes.

Monofacial and Bifacial Micro PV Installation as Element of Energy Transition—The Case of Poland

The several government subsidies available in Poland contributed to an increased interest in PV installations. Installed PV capacity increased from 100 MW in 2016 up to 2682.7 MW in July 2020. In 2019 alone, 104,000 microinstallations (up to 50 kWp) were installed in Poland. The paper determines the energy gain and the associated reduction of CO2 emissions for two types of solar installation located in Poland. The monofacial solar modules with a power of 5.04 kWp (located in Leki) and bifacial solar modules with a power of 6.1 kWp (located in Bydgoszcz). Both installations use mono-crystalline Si-based 1st generation PV cells. With comparable insolation, a bifacial installation produces approx. 10% (for high insolation) to 28% (for low insolation) more energy than a monofacial PV installation. Avoided annual CO2 emission in relation to the installation capacity ranges from 0.58 to 0.64 Mg/kWp for monofacial and from 0.68 to 0.74 Mg/kWp for bifacial and is on average approx. 16% higher for bifacial installations. Cost-benefit analyses were made. For different electricity prices, the NPV for monofacial and bifacial was determined.

Differentiation of the Level of Sustainable Development of Energy Markets in the European Union Countries

The economic development of the EU’s countries depends on stable and permanent access to various energy sources. The integration of European energy markets is a long-term process. Each member country has a different energy balance, energy resources and electricity generation technologies. Therefore, comparing Member States with one another is a complex task. The article deals with organizing the set of objects in multidimensional spaces of variables from the point of view of a certain characteristics that cannot be measured in a simple way, i.e., the relative level of the development of energy markets. The following diagnostic variables were adopted for the analysis: consumption of electric energy generated from renewables per capita (TWH/person), hard coal consumption (million tons/person), greenhouse gas emissions per capita, available for final consumption gigawatt-hour per person, final energy consumption thousand tons of oil equivalent (TOE) per person, petroleum available for final consumption (gigawatt-hour), natural gas (terajoule gross calorific value-GCV) per person, energy intensity of GDP (kilograms of oil equivalent (KGOE) per thousand euro, import dependency %. The article draws upon the cluster analysis, which uses the methods and techniques that enable to extract such objects (countries) from the data set, which would be similar to each other and combine them into groups. The purpose of the article is to examine and discus the diversity of Member States on the level of development of energy markets taking into account the specific situation of Poland. The presented model has the potential to be used at the level of enterprises from various industries to evaluate the level of sustainable development. The algorithm modification will only require the selection of available diagnostic variables describing the given enterprise.

Energy and Climate Policy—An Evaluation of Global Climate Change Expenditure 2011–2018

Concern for climate change is one of the drivers of new, transitional energy policies oriented towards economic growth and energy security, along with reduced greenhouse gas (GHG) emissions and preservation of biodiversity. Since 2010, the Climate Policy Initiative (CPI) has been publishing annual Global Landscape of Climate Finance reports. According to these reports, US$3660 billion has been spent on global climate change projects over the period 2011–2018. Fifty-five percent of this expenditure has gone to wind and solar energy. According to world energy reports, the contribution of wind and solar to world energy consumption has increased from 0.5% to 3% over this period. Meanwhile, coal, oil, and gas continue to supply 85% of the world’s energy consumption, with hydroelectricity and nuclear providing most of the remainder. With this in mind, we consider the potential engineering challenges and environmental and socioeconomic impacts of the main energy sources (old and new). We find that the literature raises many concerns about the engineering feasibility as well as environmental impacts of wind and solar. However, none of the current or proposed energy sources is a “panacea”. Rather, each technology has pros and cons, and policy-makers should be aware of the cons as well as the pros when making energy policy decisions. We urge policy-makers to identify which priorities are most important to them, and which priorities they are prepared to compromise on.

Global and regional probabilities of major nuclear reactor accidents

The continued and extended use of nuclear power is often considered and discussed as a viable energy policy option to meet energy demands while also meeting national CO₂ emission reduction goals. A central issue in energy policy for sustainability is the question of nuclear reactor safety. However, studies on nuclear reactor safety often run up against the problem of estimating the probability of a major accident from patchy and limited empirical data. Here, we describe a simple probabilistic model of catastrophic nuclear reactor accidents based on a set of four assumptions. The model treats the accident probability in each of n reactors as a variable and returns the probability of a major accident in the reactor fleet. We find that, at 99.5% reactor safety, the probability of another Chernobyl- or Fukushima-sized event is 49% for the global fleet, and that safety would have to be 99.96% in order to bring that probability below 5%. We discuss our findings in light of the debate on energy policy for sustainability.

The impacts of sodium nitrate on hydration and microstructure of Portland cement and the leaching behavior of Sr2

Immobilization and solidification of low-level and intermediate-level radioactive waste liquid from nuclear power station involves the interaction between highly concentrated sodium nitrate solution and cement paste. This study aims to clarify the influence of sodium nitrate on the hydration kinetics of cement matrices, hydration products and microstructure. The hydration heat evolution in the first 28 days are tested by calorimetry. The hydration products are examined by XRD and DTG while the structure of C-S-H is characterized by NMR, FTIR and XPS. The results indicate that sodium nitrate reduced the degree of hydration and reduced the degree of the polymerization of C-S-H gel. The C-S-H of solidified cement matrices that contained the highest concentration of sodium nitrate is predominantly composed of Q² and Q¹ Si, while more Q³ units are found in the matrices without sodium nitrate. The decomposition temperature of Ca(OH)₂ decreased with the increasing concentration of sodium nitrate solution because of the geometrical transformation of Ca(OH)₂. Sodium nitrate in solidified cement matrices mainly existed in the form of granular crystalline phase. The cumulative leaching fraction of Sr²⁺ increases with the increasing concentration of NaNO₃ solution.

Nuclear wastewater decontamination by 3D-Printed hierarchical zeolite monoliths

The selective removal of radioactive cationic species, specifically ¹³⁷Cs⁺ and ⁹⁰Sr²⁺, from contaminated water is critical for nuclear waste remediation processes and environmental cleanup after accidents, such as the Fukushima Daiichi Nuclear Power Plant disaster in 2011. Nanoporous silicates, such as zeolites, are most commonly used for this process but in addition to acting as selective ion exchange media must also be deployable in a correct physical form for flow columns. Herein, Digital Light Processing (DLP) three-dimensional (3D) printing was utilized to form monoliths from zeolite ion exchange powders that are known to be good for nuclear wastewater treatment. The monoliths comprise 3D porous structures that will selectively remove radionuclides in an engineered form that can be tailored to various sizes and shapes as required for any column system and can even be made with fine-grained powders unsuitable for normal gravity flow column use. 3D-printed monoliths of zeolites chabazite and 4A were made, characterized, and evaluated for their ion exchange capacities for cesium and strontium under static conditions. The 3D-printed monoliths with 50 wt% zeolite loadings exhibit Cs and Sr uptake with an equivalent ion-capacity as their pristine powders. These monoliths retain their porosity, shape and mechanical integrity in aqueous media, providing a great potential for use to not only remove radionuclides from nuclear wastewater, but more widely in other aqueous separation-based applications and processes.

3D-printed monoliths of zeolites chabazite and 4A were made, characterized, and shown effective for removing strontium and caesium from water.

Response to "Regarding nuclear energy: Between global electricity demand, worldwide decarbonisation imperativeness, and planetary environmental implications"

In their critical comments, Davies et al. (2019) claim that our paper (Prăvălie and Bandoc, 2018) features a series of shortcomings, such as the lack of quantitative or qualitative weighting of the nuclear energy trilemma, the insufficient analysis of specialized scientific literature or the presence of certain inconsistencies and inaccuracies throughout the paper. Starting from the idea that debate in the nuclear energy sector, in this particular instance, or in science, in general, is constructive, as long as based on credible arguments, we acknowledge these comments and wish to provide pertinent responses for each critical observation. Given this context, this scientific communication is meant to provide explanations and justify the fact that the findings of the original review-type paper (Prăvălie and Bandoc, 2018) are real and supported by various relevant scientific data and papers, and that our vision on the global nuclear energy trilemma is sufficiently substantiated.