Adaptation of conventional water treatment technologies for organic component removal from liquid radioactive waste: sorption and coagulation mechanisms.

ABSTRACT Efficient separation of long-lived, trivalent actinides from the chemically similar lanthanide fission products remains a significant challenge in nuclear waste management. In solvent extraction processes, phase modifiers are often employed to enhance the solubility of extractants in process-relevant, aliphatic diluents while suppressing the formation of third phases. This work investigates the use of 2,6-bis(5,6-bis(3-butyoxyphenyl)-1,2,4-triazinyl-3-yl)pyridine (BOB-BTP) for the extraction of 241Am3+ over 154–152Eu3+. The impact of the phase modifier (1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol) (Cs-7SB), routinely employed for 137Cs and 90Sr extractions in an Isopar/HNO3(aq) biphasic system was systematically assessed for potential utility with BOB-BTP. A 10:1 Isopar:Cs-7SB ratio greatly enhanced complexant solubility and extraction efficiency, while simultaneously suppressing the formation of precipitates. Extraction studies conducted up to 2M HNO3(aq) confirmed high chemoselectivity for 241Am3+ and excellent resistance to hydrolytic degradation of the complexant. Evaluation of decomplexation was also studied. BOB-BTP was recycled through two successive extraction sequences, thereby suggesting a high potential for reusability without diminished performance. The findings demonstrate the potential of this complexant-diluent combination for advancing partitioning applications toward closure of the nuclear fuel cycle and mitigation of the long-term radiotoxicity of spent nuclear fuel. Evaluation of acid and complexant concentration variance, in addition to decomplexation and recyclability for multiple extractions are reported herein.

SPS fabrication of mineral-like ceramics sourced by coal fly ash microspheres for 137Cs ultimate disposal in igneous rocks.

The homogeneity of bentonite-graphite (B-G) mixtures is essential for the performance of engineered barrier systems in high-level radioactive waste (HLW) repositories. Uniform graphite distribution enhances thermal conductivity while maintaining the protective functions of bentonite. This study investigates the feasibility of using visible and near-infrared (VIS-NIR) spectroscopy combined with partial least squares regression (PLSR) to assess B-G mixture homogeneity. Small-quantity mixtures containing 0-5 wt% graphite were prepared, and hyperspectral data (400-1,000nm) were collected. A PLSR model was developed to predict graphite content from the spectral data, achieving high accuracy (R² = 0.992, RMSE = 0.151 wt%) using five latent variables. The model was applied to large-scale mixtures blended using a double helix screw mixer. Samples collected at different time intervals were evaluated to determine the required mixing time for achieving homogeneity. After 120min of mixing, statistical tests confirmed uniform graphite distribution. Buffer blocks were then fabricated using both homogeneous and inhomogeneous mixtures. Blocks from homogeneous mixtures showed no visible defects, whereas those from inhomogeneous mixtures exhibited edge spalling and lateral cracking. These results demonstrate that VIS-NIR spectroscopy with PLSR is a reliable, nondestructive method for evaluating mixture homogeneity and offers practical advantages for quality control in HLW buffer material production.

A review of multiphysics coupling numerical modeling techniques for risk assessment in geological disposal of high-level radioactive waste.

Efficient removal of 99TcO4- from nuclear waste is critical for radioactive waste disposal, yet current adsorbents face limitations in capacity and mechanistic clarity due to multimechanism interference. Herein, we propose a knowledge-data dual-driven (DKD) machine learning (ML) framework to elucidate the dominant mechanism for ReO4- (a nonradioactive surrogate for 99TcO4-) adsorption on covalent organic frameworks (COFs). By integrating domain-knowledge (expressed as mathematical descriptors for five adsorption mechanisms) into the ML model, the DKD approach achieved higher predictive accuracy (R2 = 0.93) and interpretability than the purely data-driven model (R2 = 0.91). SHAP analysis of the DKD model quantitatively identified the electrostatic interaction as the primary mechanism, contributing 66.7% to ReO4- uptake. Guided by this insight, we first broke through the conventional building block charge enhancement by directly introducing charge at the linkage, designing Tb-APDC-M─an imine-linked COF with an ultrahigh charge density. It achieved a record ReO4- adsorption capacity of 1689.78 mg g-1 (pH = 7, T = 298.15 K, dosage = 0.5 g/L), significantly exceeding the previous maximum of 1262 mg g-1. Spectral and DFT calculations confirm that the exceptional performance stems from the high charge density imparted by the iminium linkage. This work highlights the DKD framework's efficiency in pinpointing key mechanisms and enabling targeted adsorbent design for 99TcO4- removal.

Mechanism of Eu(Ⅲ) adsorption and mineral alteration response of Tamusu claystones in Inner Mongolia.

This Perspective article reviews the current knowledge regarding the interaction of actinide elements with biomolecules, particularly amino acids, peptides, and proteins. We assess the significance of these interactions, especially in connection to nuclear waste disposal and the potential role of these interactions in the origin of life. Actinides have been observed to form stable complexes with carboxylate groups, resulting in oligomerization and affecting their environmental mobility. The text discusses the complex coordination chemistry of actinides, including the prevalence of hexanuclear An4+ clusters, and the implications of these findings for actinide transport and bioavailability as well as remaining challenges especially for mechanistic and thermodynamic aspects of this chemistry. Recent discoveries of lanthanide- and actinide-dependent enzymes, including methanol dehydrogenase and lanmodulin, suggest a potential for these elements to have been actively involved in early metabolic processes, rather than solely acting as environmental stressors. Despite the absence of direct evidence connecting natural reactors to the process of abiogenesis, a comprehensive understanding of actinide-biomolecule interactions is imperative for the evaluation of the nuclear geyser model and the resolution of the long-term challenges posed by the management of radioactive waste.

Evaluating the risk of induced seismicity in nuclear waste disposal

Hydrothermal synthesis and growth of stable strontium apatite for radioactive salt waste immobilization

ABSTRACTEnvironmental contamination alters ecological interactions among organisms, including those associated with parasitism. Contaminants can mediate parasitic relationships at multiple scales by changing host vulnerability to infection and disrupting transmission‐relevant contacts. The overall effect of contamination on parasitism remains poorly understood, yet the interplay between these stressors has significant implications for animal and human health. We conducted a community‐scale field study to evaluate whether trace element contaminants derived from coal combustion residuals and nuclear fission products alter the dynamics of haemosporidian blood parasites, dipteran vectors, and avian hosts in riparian and wetland habitats in South Carolina, USA. We captured 329 individuals of 31 passerine bird species and 195 Culex mosquito vectors at two sites affected by coal combustion waste, two sites affected by nuclear fission waste, and two reference sites. We evaluated whether blood concentrations of zinc, copper, mercury, and selenium and whole‐body radioactivity concentrations because of cesium‐137 predicted the likelihood of single and coinfections by Plasmodium, Haemoproteus, and Leucocytozoon within passerine hosts. We also evaluated whether the likelihood of Plasmodium infection in Culex vectors differed with the presence of site‐level contamination. Individual passerine hosts inhabiting coal combustion waste sites had significantly higher blood selenium concentrations than those at reference sites, and blood selenium was negatively associated with the likelihood of Leucocytozoon infection. The likelihood of infection with Plasmodium did not vary between vectors at contaminated versus reference sites. The transfer of low‐dose, waste‐derived selenium to wildlife may bolster individual response to some parasites and increase the reservoir capacity of host populations. Our findings highlight complex effects of trace elements on wildlife disease dynamics and reveal priorities for future research in contaminated habitat.

Nuclear power plant multi-grade waste heat-enhanced salinity-gradient osmotic energy conversion under reverse temperature gradients

THEREDA: Thermodynamic reference database for geochemical modelling of nuclear waste disposal under saline conditions – Application, overview, and new developments

Study of chemical stability and immobilization mechanism in ZIT-Eu glass-ceramic composites embedded with Eu2O3 as a radioactive waste form

Scalable production methodology of radionuclide reference materials for nuclear decommissioning and food safety monitoring.

Revolutionizing radioactive waste resin treatment: A comprehensive review of advanced technologies and future directions

Field Grouting Test Study for High-Level Radioactive Waste Disposal at the Beishan Underground Research Laboratory

Role of biotite content and structure in controlling Cesium diffusion in granitic rocks.

Stability and transformation of neptunium (Np) species under geological disposal conditions of high-level radioactive waste (HLW).

Corrigendum to “Parameters affecting EU-DEMO radioactive waste generation and mitigation techniques” [Fusion Engineering and Design, 220, 2025, 115301