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With the improvement of laser technology, the strategic needs of efficient and precise decontamination of various components in nuclear application units can be fulfilled by laser decontamination. The surface contaminants of nuclear facilities mainly exist both as loose contaminated layer and fixed oxide layer. The types of radionuclides and contamination layer thickness are closely related to the operation status of nuclear facilities, which have an important influence on the laser decontamination process. This study reviewed the mechanism of laser surface treatment and the influence of laser process parameters on the decontamination thickness, decontamination factor, decontamination efficiency and the distribution of aerosol particle. Although multiple studies have been performed on the mechanism of laser processing and laser decontamination process, there are few studies on the microscopic process mechanism of laser decontamination and the influence of laser decontamination on surface properties. In particular, the interaction between laser and radioactive contaminants needs more research in the future.

• A biomass porous carbon material was synthesized using rape pollen as the precursor. • The K-RPC demonstrates exceptional iodine capture performance. • A maximum adsorption capacity of 3842 mg/g for iodine vapor. • A superior iodine removal efficiency from cyclohexane solution, reaching 411 mg/g. • Potential future applications of raape pollen will enhance the utilization. The efficient adsorption and storage of radioactive iodine from uranium fission reactions is essential for safe nuclear energy. Bio-based adsorption materials have gained significant attention in the field of radioactive contaminants removal. This is primarily due to their numerous advantages, including a wide range of raw material sources, low cost, ease of preparation, low toxicity, high removal efficiency and stable storage. In this study, rape pollen was chosen as sources of biomass porous carbon, which possesses a micron-sized ellipsoidal shape, homogeneous size, porous structure with sparsely linked network inside, and high carbon content. A biomass derived porous carbon (K-RPC) was synthesized by pretreatment, heat treatment, and advanced treatment techniques. The results indicate that the K-RPC exhibited a hierarchical porous structure with homogeneous and wormhole-like micro- or nanopores, and high specific surface area. The K-RPC demonstrates exceptional iodine capture performance, the capacity surpasses that of most bio-based adsorbents. Remarkably, the maximum adsorption capacity of iodine vapor is approximately fifteen times higher than that of commercial silver exchanged zeolite. The adsorption mechanism, primarily characterized by chemisorption. This study is the first attempt to apply pollen in the field of iodine capture, and the biomass porous carbon extracted from rape pollen has the potential to be a cost-effective iodine adsorption material. [ABSTRACT FROM AUTHOR]

The Arctic is saturated with nuclear facilities bringing both benefits for regional economic and social development and risks of nuclear and radiological accidents and concerns about radioactive wastes. There is every reason to expect the Arctic will remain a nuclearized region during the foreseeable future. This makes it important to direct attention to issues of nuclear safety and security in the region. We identify several clusters of these issues in the Arctic, including the challenges of potential nuclear accidents, the handling of spent nuclear fuel and radioactive waste, the cleanup of radiological contaminants, and concerns about nuclear security. An analysis of international conventions and voluntary codes of conduct shows that they are applicable to Arctic nuclear safety and security, but only in general terms. This suggests a need for an Arctic-specific agreement on nuclear and radiological safety, emergency preparedness and response, and cleanup of radiological contaminants. The outbreak of military hostilities in Ukraine in February 2022 has disrupted normal procedures for addressing issues of common concern in the Arctic. But the need for cooperation regarding matters like nuclear safety and security will not go away. Assuming it is possible to devise “necessary modalities” for restarting the work of the Arctic Council following the acute phase of the Ukraine crisis, an Arctic-specific agreement on nuclear safety and security could be developed under the auspices of the Arctic Council, which already has taken an interest in nuclear safety through the activities of its Working Group on Emergency Prevention, Preparedness and Response. Once such an agreement is in place, it will become important to consider the infrastructure needed to ensure that its provisions are implemented effectively.

The article discusses the decision by Japan to release wastewater from the Fukushima Daiichi nuclear disaster into the ocean, which has raised concerns and protests from various countries and the international community. The water has been treated to remove most radioactive contaminants, but there are still concerns about the long-term effects, particularly regarding substances like tritium and carbon-14. The article also highlights the potential transportation of radionuclides by ocean currents and the lack of accepted standards for the disposal of nuclear-contaminated water. It concludes by calling for more research and international laws to prevent the discharge of nuclear sewage into the ocean. [Extracted from the article]

The potential use of stable fission products from the decay of radioactive contaminants in recreating the impact assessment of radioactivity releases from nuclear power stations is examined. With the advances in mass spectrometry, Minimum Detectable Limits (MDLs) comparable to radioactive measurements have been achieved in the case of stable isotopes as well. The applications of stable fission products in safeguards and environmental surveillance by the author are mentioned. The limited application of stable fission products in the analysis of Fukushima environmental samples is reviewed. The article examines the possible candidates for such analysis and points out the enormous possibilities. This is a neglected field in environmental impact assessment till now and calls for standardizing measurement procedures and analysis methodologies. The stable fission product signatures can also be used to study the uptake and transport of radionuclides in the environment.

The Arctic is saturated with nuclear facilities bringing both benefits for regional economic and social development and risks of nuclear and radiological accidents and concerns about radioactive wastes. There is every reason to expect the Arctic will remain a nuclearized region during the foreseeable future. This makes it important to direct attention to issues of nuclear safety and security in the region. We identify several clusters of these issues in the Arctic, including the challenges of potential nuclear accidents, the handling of spent nuclear fuel and radioactive waste, the cleanup of radiological contaminants, and concerns about nuclear security. An analysis of international conventions and voluntary codes of conduct shows that they are applicable to Arctic nuclear safety and security, but only in general terms. This suggests a need for an Arctic-specific agreement on nuclear and radiological safety, emergency preparedness and response, and cleanup of radiological contaminants. The outbreak of military hostilities in Ukraine in February 2022 has disrupted normal procedures for addressing issues of common concern in the Arctic. But the need for co operation regarding matters like nuclear safety and security will not go away. Assuming it is possible to devise "necessary modalities" for restarting the work of the Arctic Council following the acute phase of the Ukraine crisis, an Arctic-specific agreement on nuclear safety and security could be developed under the auspices of the Arctic Council, which already has taken an interest in nuclear safety through the activities of its Working Group on Emergency Prevention, Preparedness and Response. Once such an agreement is in place, it will become important to consider the infrastructure needed to ensure that its provisions are implemented effectively. [ABSTRACT FROM AUTHOR]

The potential use of stable fission products from the decay of radioactive contaminants in recreating the impact assessment of radioactivity releases from nuclear power stations is examined. With the advances in mass spectrometry, Minimum Detectable Limits (MDLs) comparable to radioactive measurements have been achieved in the case of stable isotopes as well. The applications of stable fission products in safeguards and environmental surveillance by the author are mentioned. The limited application of stable fission products in the analysis of Fukushima environmental samples is reviewed. The article examines the possible candidates for such analysis and points out the enormous possibilities. This is a neglected field in environmental impact assessment till now and calls for standardizing measurement procedures and analysis methodologies. The stable fission product signatures can also be used to study the uptake and transport of radionuclides in the environment. [ABSTRACT FROM AUTHOR]

Abstract Background After the accident at the Fukushima Daiichi Nuclear Power Plant, radioactive contaminants were released over a widespread area. Monitoring the biological effects of radiation exposure in animals in the ex-evacuation zone should be continued to understand the health effects of radiation exposure in humans. The present study aimed to clarify the effects of radiation by investigating whether there is any alteration in the morphology and gene expressions of immune molecules in the intestine of pigs and inobuta (wild boar and domestic pig hybrid) in the ex-evacuation zone in 2012. Gene expression analysis was performed in small intestine samples from pigs, which were collected from January to February 2012, in the ex-evacuation zone. Pigs lived freely in this zone, and their small intestine was considered to be affected by the dietary intake of radioactive contaminants. Results Several genes were selected by microarray analysis for further investigation using real-time polymerase chain reaction. IFN-γ, which is an important inflammatory cytokine, and TLR3, which is a pattern recognize receptor for innate immune system genes, were highly elevated in these pigs. The expressions of the genes of these proteins were associated with the radiation level in the muscles. We also examined the alteration of gene expressions in wild boars 5 years after the disaster. The expression of IFN-γ and TLR3 remained high, and that of Cyclin G1, which is important in the cell cycle, was elevated. Conclusions We demonstrated that some changes in gene expression occurred in the small intestine of animals in the ex-evacuation zone after radiation. It is difficult to conclude that these alterations are caused by only artificial radionuclides from the Fukushima Daiichi Nuclear Power Plant. However, the animals in the ex-evacuation zone might have experienced some changes owing to radioactive materials, including contaminated soil, small animals, and insects. We need to continue monitoring the effects of long-term radiation exposure in living things.

Abstract Recent studies have confirmed historic atmospheric deposition of uranium in Antarctica, with a steep and significant increase in levels deposited since the 1980s in Antarctic Peninsula ice core samples. To date, however, there has been little or no attention paid to uranium in the Antarctic food web. Here, we present results for uranium content in scales of three common nototheniid species (Trematomus bernacchii , Gobionotothen gibberifrons , Notothenia coriiceps) from coastal waters off James Ross Island (Antarctic Peninsula). While mean total uranium levels (mean ± SD) were low and similar between species (N. coriiceps 0.08 μg g−1 ± 0.01, T. bernacchii 0.17 μg g−1 ± 0.10; G. gibberifrons 0.11 μg g−1 ± 0.04), linear regressions against standard length indicated bioaccumulation in T. bernacchii (ANOVA, F = 7.8349, P = 0.0076). We suggest this may be the result of dietary specialisation on prey with calcareous shells that accumulate uranium. To the best of our knowledge, this paper provides the first quantitative baseline data on uranium levels in coastal Antarctic nototheniids. While the low levels recorded are unlikely to represent a threat within the food chain, we suggest that further long-term trophic studies (including stable isotope analysis) are needed, recognising that the feeding ecology of individual species (and even individuals) can have a strong effect on overall trends. Graphical abstract Image 1 Highlights • First quantitative baseline uranium levels presented for Antarctic nototheniids. • Levels low but emerald rockcod show evidence of bioaccumulation. • Bioaccumulation linked with dietary specialisation on molluscs? • Possible links with atmospheric deposition and climate change. • In depth trophic studies needed on Antarctic food-web dynamics. [ABSTRACT FROM AUTHOR]

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The soil-plant transfer of Cs-137 and Sr-90 in different crops was determined with respect to the present-day amendment practice of using digestate from biogas fermenters. The studies were performed using large lysimeters filled with undisturbed luvisol monoliths. In contrast to the conservative tracer, Br − , neither of the studied radionuclides showed a significant vertical translocation nor effect of the applied digestate amendment compared to a non-amended control was found. Furthermore, no significant plant uptake was measured for both nuclides in wheat or oat as indicated by the low transfer factors between soil-shoot for Cs-137 (TF 0.001–0.010) and for Sr-90 (0.10–0.51). The transfer into nutritionally relevant plant parts was even lower with transfer factors for soil-grain for Cs-137 (TF 0.000–0.001) and for Sr-90 (0.01–0.06). Hence, the amendment with biogas digestate is unfortunately not an option to further reduce plant uptake of these radionuclides in agricultural crops, but it does not increase plant uptake either. [ABSTRACT FROM AUTHOR]

Aims p-tertbutylcalix [4] arene loaded nanoemulsion has been designed, characterized and evaluated for skin decontamination of radionuclides of interest in nuclear and radiological emergencies. Further, nanoemulsion was evaluated for Ex-vivo complexation, skin permeation, interaction and cytodermal toxicity. Materials and methods Ex-vivo skin complexation studies were conducted using High-resolution sector field inductively coupled plasma mass spectroscopy (HR-SF-ICPMS). Skin studies at dermal and cyto-dermal level have been carried out using techniques such as florescence microscopy, Differential scanning calorimetry (DSC), Flow cytometry, Confocal microscopy, Prestoblue and Comet assay. Key findings HR-SF-ICPMS study confirmed > 95% complexation of surrogate nuclides of thallium and Iodine applied on excised rat skin mounted over Franz diffusion cell. Temporal analysis of aliquots obtained from Franz diffusion cell using UV–Vis absorption spectroscopy indicated that only 3.37% of formulation permeates through the skin. Skin penetration study of rhodamine 123 nanoemulsion carried out using florescence microscopy confirmed that formulation remains localised in epidermis of rat skin. DSC data confirmed skin compatibility of nanoemulsion, as no lipid extraction was observed from skin. In-vitro cell viability and cellular uptake assays performed on human skin fibroblasts prove no cellular uptake and cytotoxic effects. Comet assay, cell cycle arrest, and apoptosis-inducing mechanistic studies prove that prepared nanoemulsion is safe at cellular level. Significance Taken together, data indicate that p-tertbutylcalix [4] arene nanoemulsion is both effective and safe formulation to use on skin for radio-decontamination. [ABSTRACT FROM AUTHOR]

The presence of organics may enhance contaminant mobility; thus, the evaluation of radionuclide-organic-cement interactions is a topic of particular interest for the safety assessment of low-intermediate level radioactive waste (LILRW) disposals. The objective of this work is to analyse nickel adsorption on the most abundant phases of hydrated cement paste, calcium silicate hydrate (CSH), in the presence of isosaccharinic acid (Isa), the principal degradation product of cellulose under alkaline conditions. Two different CSHs were studied (Ca/Si ratios of 0.8 and 1.4) to cover a range of chemical conditions representative of different cement degradation stages. To gather information on the interactions in the ternary Ni/Isa/CSH system, batch sorption tests, electrophoretic measurements, and spectroscopic analyses (FT-IR) were combined. The presence of Isa at a concentration up to 1·10−2 M slightly decreased the surface charge (−10 mV) of the two CSH phases analysed, and moderately affected Ni adsorption, causing a diminution of K d (Ni) by less than 1 order of magnitude. To interpret the experimental dataset, surface complexation modelling was successfully used in this system for the first time. The modelling was based on a double layer approach, which accounts for the properties of the binary Ni/CSH system and includes the formation of Ni-Isa aqueous complexes as well as Isa adsorption on the CSH, under the specific chemical conditions generated by the solids. [Display omitted] • The presence of Isa slightly modified the CSH gels surface charge (−10 mV). • The presence of Isa reduced Ni adsorption on CSH gels by a factor 4–5. • The formation of Ni-Isa complexes controls Ni retention on the CSH gels. • Isa adsorption on CSH is proven, but it slightly affects the overall Ni behaviour. • Sorption modelling explains the behaviour of the ternary Ni/Isa/CSH system. [ABSTRACT FROM AUTHOR]

Imidazolium-based ionic liquids (ILs) are a promising candidate for efficient separation of radioactive pertechnetate (TcO 4 -) from nuclear waste. However, their effective fixation, availability of active sites and slow adsorption kinetics remain challenges. Here, we incorporated the bisimidazolium-based ILs into porous metal-organic frameworks (MOFs) via a combination of immersion grinding and in-situ polymerization. 3,3′-divinyl-1,1′(1,4-butanediyl) diimidazolium dichloride is tightly bound inside and outside the porous MOFs matrix by uniform immersion grinding, which facilitates the exposure of more adsorption sites and provides channels for the anions to travel through quickly. Solvent-free polymerization reduces environmental pollution and energy consumption. Notably, the composite P[C 4 (VIM) 2 ]Cl 2 @MIL-101 possesses an admirable removal efficiency (673 mg g−1) compared with the pristine poly(ionic liquid)s (215 mg g−1). Meanwhile, it exhibits fast sorption kinetics (92% in 2 min), good β and γ radiation-resistance, excellent regeneration and eminent removal efficiency in high alkaline conditions (83%). These superior traits endow that P[C 4 (VIM) 2 ]Cl 2 @MIL-101 effectively separated TcO 4 - from simulated Hanford Low-activity Waste (LAW) Melter off-gas scrubber solution tested in this work. DFT density functional theory confirms that the strong electrostatic attraction and minimum Gibbs free energy (−6.2 kcal mol−1) achieve high selective adsorption for TcO 4 -. P[C 4 (VIM) 2 ]Cl 2 @MIL-101 demonstrates the considerable potential to remove TcO 4 - from radioactive contaminants. [Display omitted] • Simple immersion grinding and in-situ polymerization methods were used to synthetize. • Solvent-free polymerization lowers environmental pollution and energy consumption. • The adsorption capacity of 673 mg g−1 benefits from fully exposed active sites. • Porous matrix MIL-101 promotes fast adsorption kinetics. • Combine excellent selectivity, radiation resistance and regenerability in one. [ABSTRACT FROM AUTHOR]

The main limitation in the high-sensitive HPGe gamma-ray spectrometry has been the detector background, even for detectors placed deep underground. Environmental radionuclides such as 40 K and decay products in the 238 U and 232 Th chains have been identified as the most important radioactive contaminants of construction parts of HPGe gamma-ray spectrometers. Monte Carlo simulations have shown that the massive inner and outer lead shields have been the main contributors to the HPGe-detector background, followed by aluminum cryostat, copper cold finger, detector holder and the lead ring with FET. The Monte Carlo simulated cosmic-ray background gamma-ray spectrum has been by about three orders of magnitude lower than the experimental spectrum measured in the Modane underground laboratory (4800 m w.e.), underlying the importance of using radiopure materials for the construction of ultra-low-level HPGe gamma-ray spectrometers., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: After the accident at the Fukushima Daiichi Nuclear Power Plant, radioactive contaminants were released over a widespread area. Monitoring the biological effects of radiation exposure in animals in the ex-evacuation zone should be continued to understand the health effects of radiation exposure in humans. The present study aimed to clarify the effects of radiation by investigating whether there is any alteration in the morphology and gene expressions of immune molecules in the intestine of pigs and inobuta (wild boar and domestic pig hybrid) in the ex-evacuation zone in 2012. Gene expression analysis was performed in small intestine samples from pigs, which were collected from January to February 2012, in the ex-evacuation zone. Pigs lived freely in this zone, and their small intestine was considered to be affected by the dietary intake of radioactive contaminants., Results: Several genes were selected by microarray analysis for further investigation using real-time polymerase chain reaction. IFN-γ, which is an important inflammatory cytokine, and TLR3, which is a pattern recognize receptor for innate immune system genes, were highly elevated in these pigs. The expressions of the genes of these proteins were associated with the radiation level in the muscles. We also examined the alteration of gene expressions in wild boars 5 years after the disaster. The expression of IFN-γ and TLR3 remained high, and that of Cyclin G1, which is important in the cell cycle, was elevated., Conclusions: We demonstrated that some changes in gene expression occurred in the small intestine of animals in the ex-evacuation zone after radiation. It is difficult to conclude that these alterations are caused by only artificial radionuclides from the Fukushima Daiichi Nuclear Power Plant. However, the animals in the ex-evacuation zone might have experienced some changes owing to radioactive materials, including contaminated soil, small animals, and insects. We need to continue monitoring the effects of long-term radiation exposure in living things.

Layered titanate nanofibers can absorb bivalent ions from waste water via an ion exchange process. The sorption induces a considerable deformation of the layered structure, thus trapping the cations in the fibers permanently. Therefore, the fibers are desirable sorbents for the removal of toxic, radioactive Ra(2+) and Sr(2+) ions from water and subsequent safe disposal thereof., (Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)