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AbstractThe paper is focused on how to apply the probabilistic safety assessment (PSA) methodology to assess the nuclear safety risks associated with the transportation of radioactive material. The methodology is comprehensive and covers the different modes of transport (for example, by road, by train, by ship, and by air) used for the transportation of radioactive material. The proposed methodology can be applied to any specific mode of transportation of radioactive material as well as to any specific country. This paper focuses on application of this methodology for transportation of radioactive material by train.The systematic assessment starts with the identification of the risk associated with the transportation mode and its initiating events to analyze what can go wrong in the transportation of radioactive material and how likely it can be. An accident involving radioactive material has sensitive information, and such information is not publicly available. Therefore, generic accident data can be utilized to develop probabilistic models and quantify the risk associated with radioactive material transportation. Another fact is that radioactive material transportation accidents are extremely rare; hence, associated statistics are insufficient for the development of PSA models, so generic accident data can be used to predict accident frequency.The paper explores the feasibility of using probabilistic methods to assess the safety risks associated with radioactive material transport. The paper describes how to perform a comprehensive probabilistic assessment and create a generic accident event tree that is based on train accident data. The focus of the event tree is to outline a range of different train accident scenarios and their respective probabilities of occurrence and their consequences. [ABSTRACT FROM AUTHOR]

This report summarizes the findings of a workshop held at the safeND Research Symposium and hosted by the German Federal Office for the Safety of Radioactive Waste Management (BASE) in Berlin in September 2023. The workshop aimed to channel perspectives from various fields of expertise to discuss key sustainability concepts in terms of radioactive waste management. Therefore, the report highlights that current sustainability concepts, such as the United Nations' Sustainable Development Goals (SDG) as well as the concept of Planetary Boundaries, neglect challenges arising from the production and storage of human-made radioactive materials. The workshop consisted of three group tasks. The first attempted at identifying the interrelations between "sustainability" and radioactive waste management. The second was to map the global nature of the challenges. The third took first steps to determine a human-made radioactive material as a potential planetary sub-boundary for "novel entities". All three groups identified valuable knowledge gaps that should be addressed by future research and concluded that radioactive waste management is underrepresented in these sustainability concepts. [ABSTRACT FROM AUTHOR]

A case of illegal possession of suspect material at the Karasovići border crossing in Croatia was recently recorded and resolved. An increased activity of 226Ra was detected in the suspect material. The seized material consisted of 2 types of samples, black powder and jewellery. The material was analysed by the high-resolution gamma spectrometry method in the Laboratory for Radioecology of the Ruđer Bošković Institute. The seized material was confirmed to contain uranium. The material was additionally analysed by the X-ray diffraction method. Identified mineral phases have not been found in Croatia so far, therefore it is not possible that the material in question originates from Croatia. [ABSTRACT FROM AUTHOR]

As a result of the accident at the Fukushima Daiichi Nuclear Power Plant, radioactive cesium was widely dispersed, and field and forest wastes, such as cut grass and trees contaminated with radioactive cesium, was buried at municipal waste final disposal sites after they were burned at incineration facilities. Radioactive cesium could be managed until the final disposal site is decommissioned, so the long-term effects of radiation and how long to manage them have become important issues for final disposal sites related persons. Therefore, in order to understand the current status of radioactive cesium concentrations at the municipal waste final disposal sites in Fukushima prefecture, the relationships between the radioactive cesium concentration in leachate and the concentration of elements such as chloride ion, sodium, and strontium in the leachate were quantitatively clarified for five municipal waste final disposal sites in Fukushima Prefecture, and based on these relationships, correlation equations were derived which can predict the present status of radioactive cesium concentration. In addition, the distributions of radioactive cesium concentration and composition ratio in the depth direction of the final disposal site were experimentally clarified by quantitative analyses for multiple landfill wastes collected at arbitrary positions up to 100 cm in depth from three different spots on the surface of the municipal waste final disposal site.

The growing application of radioactive materials in various industries, such as nuclear power, oil and gas, and research labs, has led to an increase in the amount of radioactive material present in waste liquids. This poses a risk to both the environment and human health through exposure to radiation. Current methods for treating these types of waste liquids, aside from membrane technology, are not economically feasible. Therefore, it is crucial to investigate ways to effectively treat liquid radioactive waste to comply with environmental regulations. Membrane technology is a cost-effective and energy-efficient method for treating radioactive waste. This review focuses on the utilization of membrane technology for the treatment of radioactive waste, discussing various collective membrane techniques, including nanofiltration, microfiltration, ultrafiltration, membrane distillation, and reverse osmosis. The review also evaluates selective membrane separation techniques such as ion-exchange membranes, supported liquid membranes, and polymer inclusion membranes. Previous studies' findings are summarized, and potential areas for future development are highlighted. [ABSTRACT FROM AUTHOR]

The current global approach to securing potentially dangerous radioactive material needs to be strengthened. Highly radioactive sources have multiple uses globally in medicine, industry, and academic research, but terrorist and other violent groups could also use them to make a "dirty bomb," in which highly radioactive material is dispersed with conventional explosives. While global radiological security arrangements have improved since 2001, the International Atomic Energy Agency (IAEA) and national regulators still report regular incidents of highly radioactive materials that are stolen, lost, or missing. Currently, global radiological security is largely based on the IAEA's Code of Conduct on the Safety and Security of Radioactive Sources, which countries are under no obligation to follow or implement. The time has come to make the code of conduct a legally binding agreement that would promote national accountability and help prevent radiological terrorism. [ABSTRACT FROM AUTHOR]

Background: The purpose of this research was to evaluate the safety and efficacy of a self-expandable metallic stent (SEMS) combined with iodine-125 (125I) seeds in the treatment of Bismuth type I or II malignant biliary obstruction (MBO). Methods: The clinical data of 74 cases of MBO treated with percutaneous SEMS combined with 125I seeds (combination group) and 81 cases of MBO treated with SEMS implantation alone (control group) in our hospital from January 2015 to December 2019 were retrospectively analyzed. The short-term and long-term efficacy of the two groups were compared. Multivariate Cox regression analysis was used to analyze the factors affecting the surgical efficacy and survival rate. Results: The liver blood test results of both groups improved at one week and one month post-stent insertion. No significant difference was established in the short-term efficacy or complications between the two groups (P = NS). Improved stent patency was observed in the combined group, 9.01 ± 4.38 months versus 6.79 ± 3.13 months, respectively (P < 0.001). Improved survival was also noted in the combined group 12.08 ± 5.38 months and 9.10 ± 4.16 months, respectively (P < 0.001). Univariate and multivariate analyses showed that the type of biliary stent and liver metastasis were independent factors affecting survival. Conclusion: The implementation of SEMS combined with 125I seeds resulted in significantly longer stent patency and survival times than that of SEMS implantation alone, which is thus worthy of clinical promotion and application. [ABSTRACT FROM AUTHOR]

Electricity generation using nuclear power has various advantages, such as carbon reduction, but the treatment of nuclear waste is emerging as a big issue in many countries. The development of technology that can selectively remove radionuclides from liquid radioactive waste is one of the ways to reduce nuclear waste. Here, we assessed a new way of removing radioactive cobalt from a liquid using an aptamer. Aptamers specifically binding cobalt ions were selected through systematic evolution of ligands by exponential enrichment (SELEX). Their binding strength and stability of their complexes with cobalt were analyzed through surface plasmon resonance assay and 2D program Mfold, respectively. The optimal aptamer/bead conjugate conditions for binding cobalt were established using an FA-C1 aptamer with the strongest binding to cobalt. Under these conditions, more than 80% of radioactive cobalt was removed, and more than 99.95% of removed cobalt was recovered. These results proved that radioactive cobalt removal using this aptamer can effectively reduce liquid radioactive waste. This means that the aptamer/bead complex can be utilized to remove various radioactive metal ions. [ABSTRACT FROM AUTHOR]

Nuclear power is a sustainable energy source, but radiation management is required for its safe use. Radiation-detection technology has been developed for the safe management of radioactive materials in nuclear facilities but its performance may vary depending on the size and complexity of the structure of nuclear facilities. In this study, a nuclear monitoring system using a multi-sensor network was designed to monitor radioactive materials in a large nuclear facility. Additionally, an artificial-intelligence-based localization algorithm was developed to accurately locate radioactive materials. The system parameters were optimized using the Geant4 Application for Tomographic emission (GATE) toolkit, and the localization algorithm was developed based on the performance evaluation of the Artificial Neural Network (ANN) and Decision Tree (D-Tree) models. In this article, we present the feasibility of the proposed monitoring system by converging the radiation detection system and artificial intelligence technology. [ABSTRACT FROM AUTHOR]

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on March 11, 2011 resulted in the release of immense amounts of radioactive materials into the ocean. However, the dispersion of radioactive materials in the subsurface has not yet been clarified due to the spatiotemporal limitation of observations. Thus, herein, a tracer experiment was implemented using a three-dimensional numerical model to estimate the dispersion path of 137Cs released directly from the FDNPP and its travel time in the subsurface of the North Pacific Ocean from 2011 to 2020. The results show that the subsurface 137Cs spreads by two mode waters, namely, Sub-Tropical Mode Water (STMW) and Central Mode Water (CMW). Subsurface 137Cs primarily spreads clockwise in the sub-tropical region, while a portion driven by STMW is dispersed southward. The clockwise dispersion path of 137Cs released into the ocean by STMW is relatively shallower and inward than that by CMW. The 137Cs that was spread clockwise reached the east of Taiwan and the Philippines via STMW and CMW nine years after the accident, respectively. The model described in this study is applicable for estimating the water path and travel time of tritium water planned to be discharged from Fukushima.

The number of radioactive materials used in radiological facilities around the world requires an effective security system to protect both the facility and the environment. In these facilities, a Physical Protection System (PPS) is routinely devised and implemented to protect radioactive materials from potential adversaries. A physical protection system created for a hypothetical radiological site is thus evaluated against harmful actions posed by a possible attacker in this study. An Adversary Sequence Diagram (ASD) is created for a hypothetical oncology center in this study, and the effectiveness of physical protective systems is evaluated through the use of estimate of adversary sequence interruption (EASI) model for interruption of adversary action on a radiological facility. Risk assessment was done by performing iterations of probability of attacks on the facility to obtain risk values using python program. The risk assessment performed depicted the reduction of chances of possible attacks on the hypothetical facility after the application of improvement strategies. The chances of identifying and interrupting an adversary's actions toward the hypothetical radiological facility was increased significantly indicating that the PPS provides an improved reliable security system. The purpose of the work is to articulate security requirements for handling radioactive materials at a radiological facility.

Copyright of Nuclear Safety is the property of Nuclear & Radiation Safety Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nuclear Safety is the property of Nuclear & Radiation Safety Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to mitigate the damage caused by accidents in nuclear power plants (NPPs), evacuation strategies are usually managed on the basis of off-site effects such as the diffusion of radioactive materials and evacuee traffic simulations. However, the interactive behavior between evacuees and the accident environment has a significant effect on the consequential gap. Agent-based modeling (ABM) is a method that can control and observe such interactions by establishing agents (i.e., the evacuees) and patches (i.e., the accident environments). In this paper, a radiological emergency evacuation model is constructed to realistically check the effectiveness of an evacuation strategy using NetLogo, an ABM toolbox. Geographic layers such as radiation sources, roads, buildings, and shelters were downloaded from an official geographic information system (GIS) of Korea, and were modified into respective patches. The dispersion model adopted from the puff equation was also modified to fit the patches on the geographic layer. The evacuees were defined as vehicle agents and a traffic model was implemented by combining the shortest path search (determined by an A ∗ algorithm) and a traffic flow model incorporated in the Nagel-Schreckenberg cellular automata model. To evaluate the radiological harm to the evacuees due to the spread of radioactive materials, a simple exposure model was established to calculate the overlap fraction between the agents and the dispersion patches. This paper aims to demonstrate that the potential of ABM can handle disaster evacuation strategies more realistically than previous approaches.

One of the most well-liked energizing drinks is now tea, which is primarily used in Malaysia. The natural radioactivity in the associated soils where tea plants are cultivated plays a major role in determining the presence of radionuclides in tea leaves. The present study assesses the transfer of radionuclides from soil-to-tea leaves and then estimates the committed effective doses through tea consumption. Tea leaves and the associated soils were obtained from the largest tea plantation area, which is located in the Cameron Highlands, Malaysia. The marketed tea leaves in powdered form were obtained from the supermarkets in Kuala Lumpur. HPGe gamma-ray spectrometry was used to determine the prevailing concentrations of long-lived radioactive materials in tea leaves. Activity concentrations of 226Ra, 232Th, and 40K in tea soils ranged from 49 to 101.7 Bq kg−1, 74.5–124.1 Bq kg−1 and 79.6–423.2 Bq kg−1, respectively, while the respective values in tea leaves are 14.4–23.8 Bq kg−1, 12.9–29.5 Bq kg−1 and 297–387.5 Bq kg−1. Transfer factors of radionuclides showed typical values (<1.0) except for the 40K. The threshold tea consumption rates suggest that one should not consume more than 67 g of tea leaves per day (around 4 g of tea leaves are needed for making 1 cup of tea, so 17 cups per day) to avoid negative health effects. Committed effective doses due to tea consumption are found to be lower (5.18–6.08 μSv y−1) than the United Nations Scientific Committee on the Effects of Atomic Radiation (2000) reference dose guidance limit of 290 μSv y−1 for foodstuffs; however, it should be noted that the guidance limit is recommended for all foodstuffs collectively. Providing data on natural radioactivity in tea leaves grown in Malaysia, this study may help people manage a healthy lifestyle. • Radionuclides transfer from soil-to-tea leaves and associated doses are studied. • Tea leaves are collected from the largest tea estate in Malaysia. • Radioactivity in tea leaves are reported for the first time in Malaysia. • Committed effective dose found below the UNSCEAR guidance limit of 290 μSv y−1. • The reported data may be useful to maintain a healthy lifestyle. [ABSTRACT FROM AUTHOR]

This study presents a real-time monitoring technique for radioactive substances that meets safety management needs. We studied the accumulation characteristics of radiation response signals of monolithic active pixel sensors (MAPSs) based on their response and discrimination ability to gamma (γ) photon or neutron radiation. The radiation status of the radioactive substances was determined by monitoring the accumulation data of radiation responses. As per the results, Am-Be and 252Cf radiation response signals are primarily concentrated in the range of 0–70 pixels. Response signals of 60Co and 137Cs γ-ray were concentrated in two regions; there was a peak in the region with a pixel value of less than 50, and a plateau in the region with a pixel value of more than 75. Therefore, the results are able to discriminate between spectra. Furthermore, we designed a radioactivity monitoring system that is able to examine multiple radioactive materials. Its working principle is that a change in the accumulation of radioactivity monitoring data indicates a radiation change during the last accumulation cycle. This study provides vital technical support for the long-term supervision of radioactive substances. [ABSTRACT FROM AUTHOR]

This article describes and assesses the security of transport of radioactive and nuclear material in Belgium that has been boosted after the terrorist attacks in Brussels in 2016. The article looks at the different possibilities of terrorist attacks on transports of radioactive and nuclear material and the possible consequences: theft of radioactive material for use in a radioactive exposure device, a radioactive dispersal device, or an improvised nuclear weapon; or a conventional attack on a transport, releasing radiation into the environment. The focus on insider threat is a step forward, but it may not divert attention from regularly updating security measures against outsider threat. Some recommendations are provided to ensure continuous improvement in the transport of radioactive and nuclear material. [ABSTRACT FROM AUTHOR]

Capacitive deionization is an emerging and rapidly developing electrochemical technique for water desalination across the globe with exponential growth in publications. There are various architectures and materials being explored to obtain utmost electrosorption performance. The symmetric architectures consist of the same material on both electrodes, while asymmetric architectures have electrodes loaded with different materials. Asymmetric architectures possess higher electrosorption performance as compared with that of symmetric architectures owing to the inclusion of either faradaic materials, redox‐active electrolytes, or ion specific pre‐intercalation material. With the materials perspective, faradaic materials have higher electrosorption performance than carbon‐based materials owing to the occurrence of faradaic reactions for electrosorption. Moreover, the architecture and material may be tailored in order to obtain desired selectivity of the target component and heavy metal present in feed water. In this review, we describe recent developments in architectures and materials for capacitive deionization and summarize the characteristics and salt removal performances. Further, we discuss recently reported architectures and materials for the removal of heavy metals and radioactive materials. The factors that affect the electrosorption performance including the synthesis procedure for electrode materials, incorporation of additives, operational modes, and organic foulants are further illustrated. This review concludes with several perspectives to provide directions for further development in the subject of capacitive deionization. Practitioner Points: Capacitive deionization (CDI) is a rapidly developing electrochemical water desalination technique with exponential growth in publications.Faradaic materials have higher salt removal capacity (SAC) because of reversible redox reactions or ion‐intercalation processes.Combination of CDI with other techniques exhibits improved selectivity and removal of heavy metals.Operational parameters and materials properties affect SAC.In future, comprehensive experimentation is needed to have better understanding of the performance of CDI architectures and materials.The subject of capacitive deionization may be divided into two categories, namely Architectures perspective and Materials perspective. The specific architecture and material may be selected for the application in water desalination, heavy metal removal, or removal of radioactive materials. [ABSTRACT FROM AUTHOR]

Response Surface Method (RSM) is one of the most popular and powerful tools for experimental design and optimization. This paper first reviewed the research progress of RSM in the separation and recovery of various radioactive materials, and verified the application of RSM in adsorption isotherm analysis and thermodynamic calculation. The main advantage of RSM in radioactive material separation is the reduction in the number of experiments required, resulting in considerably less radioactive material consumption, secondary waste generation, workload and radiation dose, which is valuable for the research of radioactive material separation. [ABSTRACT FROM AUTHOR]

Copyright of Nuclear Safety is the property of Nuclear & Radiation Safety Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study presents a real-time monitoring technique for radioactive substances that meets safety management needs. We studied the accumulation characteristics of radiation response signals of monolithic active pixel sensors (MAPSs) based on their response and discrimination ability to gamma (γ) photon or neutron radiation. The radiation status of the radioactive substances was determined by monitoring the accumulation data of radiation responses. As per the results, Am-Be and 252Cf radiation response signals are primarily concentrated in the range of 0–70 pixels. Response signals of 60Co and 137Cs γ-ray were concentrated in two regions; there was a peak in the region with a pixel value of less than 50, and a plateau in the region with a pixel value of more than 75. Therefore, the results are able to discriminate between spectra. Furthermore, we designed a radioactivity monitoring system that is able to examine multiple radioactive materials. Its working principle is that a change in the accumulation of radioactivity monitoring data indicates a radiation change during the last accumulation cycle. This study provides vital technical support for the long-term supervision of radioactive substances.

Cesium radioactive isotopes (134Cs and 137Cs) are dangerous to human health due to their long half-life and high solubility in water. Nuclear experiments, wars, and nuclear plant accidents have been the main sources of Cs release into the environment. In recent years, several methods have been introduced for the elimination of Cs radioactive isotopes from contaminated water. This study provides an overview of the available published articles (2008–2016) regarding the remediation of waters polluted by Cs isotopes. The maximum adsorption capacity (MAC) of Cs isotopes corresponded to natural chabazite (273.24 mg Cs/g adsorbent), hollow Prussian blue (PB) nanoparticles (262 mg Cs/g adsorbent), and Prussian blue implemented non-woven fabric (260 mg Cs/g adsorbent). Using natural chabazite and PB adsorbents, along with another adsorbent (PB graphene oxide hydrogel), Cs radioactive isotopes can be effectively removed from the aqueous solutions.

All living creatures living on the earth have been exposed to radiation and intertwined with radiation throughout their entire lives. As long as there are radiation sources, it will not be possible to avoid it. The purpose of this article is to provide interaction in the sense that health and industry employees are a ware of the use of personal dosimeters by ionizing radiation emitting devices or radioactive substances and that they are able to maintain healthy working and working conditions effectively. For radiation workers, the effective dose is limited to 20 mSv for five years. However, it has been accepted that employees should not exceed 50 mSv of effective dose in a single year. The annual equivalent dose limit for hand-foot or skin was set at 500 mSv, while for the eyelid the dose was limited to 150 mSv. It is possible to read radiation doses directly from the receiving device, electronic dosimeters and pocket (pen) dosimeters. In this study, detailed information was given about the dosimeters. It is important to know the level of radiation emitted from such devices in order to be able to be protected from radiation emitted by a radioactive source or X-ray. The only way to find out is to identify the dosimetry systems of the users and to know the characteristics that will affect the measurement results, it is very important to determine the correctness of the doses.

As one of the fauna and flora reservation sites, hyrcanian forest ecosystems have experienced sever destruction during recent decades because of the improper land uses. Use of fallout radionuclide, particularly Cs137, is one of the trusty methods in soil erosion rate. The purpose of this research was to estimate soil erosion rate in Hyrcanian forest heights in Ziarat catchment using radioactive element Cs137. Therefore, first Cs137 inventory was calculated in three land uses including forest, rangeland, and cultivate lands. After that, the erosion and sedimentation rates for each land use were determined using mass balance II model for cultivate areas and intuition and diffusion model for uncultivated area. The impact of land use on the soil erosion and sedimentation rate and organic carbon storage were investigated using ANOVA. The research found that the annual Cs137 inventory estimated was 575, 286, and 258 Bq/m2 in the forest, rangeland, and cultivate lands respectively. The maximum and minimum erosion rate had occurred in cultivated land by 39.8 and forest land by 5.2 ton/ha/y respectively. In addition, there was a positive correlation between erosion and sediment rate and organic carbon storage. The findings of this research can be used for sustainable management of Ziarat Catchment.

Thin plates of duplex stainless steel UNS S32304 were welded using the pulsed gas tungsten arc GTAW process (butt joint) without filler addition. The used shielding gas was pure argon and 98% argon plus 2% of nitrogen. The thermal cycles were acquired during welding, in regions near the melting pool. This alloy is candidate for the external clad of a cask for the transport of high activity radiopharmaceuticals substances. For the residual stress measurements in austenite phase an X-ray diffractometer was used in a Bragg-Brentano geometry with CuKα radiation (λ= 0.154 nm) and for ferrite phase was used a pseudo-parallel geometry with CrKα radiation (λ= 0.2291nm). The results of residual stress using sin2y methodology shown that the influence of the high welding temperature leads to compressive stresses for both phase of the duplex steels mainly in heat-affected zone. It was observed a high temperature peak and an increase of the mean residual stress after addition of nitrogen to the argon shielding gas.

The most important factors in the manufacture of shielded sheets are shielding ratio, light weight, and tensile strength. The base material should provide a light-shielding film with strong physical shock resistance, while maintaining the shielding ratio of lead. Therefore, we studied the correlation between the porosity during the mixing process and the maintenance of the shielding film characteristics. Changes in the shielding ratio can be predicted according to the properties of materials such as polymeric silicon and tungsten oxide. Further, their tensile strength and porosity may change depending on the content of the material. Experiments were carried out for each substance based on the shielding ratio with respect to the processing conditions. For a shielding film using barium sulfate (BaSO4) and polymeric silicon, increasing the porosity by the removal of air in the same manufacturing process resulted in a tensile strength of 6.4 MPa at 22% porosity. For tungsten oxide (WO3), the tensile strength was 10.5 MPa at a porosity of 12%, and for a 0.6 mm sample, the shielding performance was very similar to 0.21 mm of Pb. The porosity during the manufacturing process affected the tensile strength and shielding performance, which were significantly different for each shielding material. [ABSTRACT FROM AUTHOR]

Prussian blue (PB) is known to be an effective material for radioactive cesium adsorption, but its nano-range size make it difficult to be applied for contaminated water remediation. In this study, a simple and versatile approach to immobilize PB in the supporting matrix via surface functionalization was investigated. The commercially available poly vinyl alcohol (PVA) sponge was functionalized by acrylic acid (AA) to change its major functional group from hydroxyl to carboxylic, which provides a stronger ionic bond with PB. The amount of AA added was optimized by evaluating the weight change rate and iron(III) ion adsorption test. The FTIR results revealed the surface functional group changing to a carboxyl group. The surface functionalization enhanced the attachment of PB, which minimized the leaching out of PB. The Cs+ adsorption capacity significantly increased due to surface functionalization from 1.762 to 5.675 mg/g. These findings showed the excellent potential of the PB-PAA-PVA sponge as a cesium adsorbent as well as a versatile approach for various supporting materials containing the hydroxyl functional group. [ABSTRACT FROM AUTHOR]

• Shows that DNA aptamers trap Nickel ions from a liquid solution. • Reveals that a column containing Beads-DNA aptamers complex removes radioactive nickel from the liquid. • Provides a simple method to recover almost 100% nickel from a column with trapped nickel. • Suggests that the column containing the aptamer-beads complex has the economic and efficient advantage of replacing the ion exchange resin used in nuclear power plants. Development of technology for removal of radioactive particles including nickel from liquid nuclear waste is necessary for maintenance of nuclear power plants. In this study, we focused on development of a method for trapping radioactive nickel ions using an aptamer capable of capturing small molecules such as metal ions. Nine rounds of SELEX were performed resulting in selection of two aptamers with high affinity for nickel. Liquid containing 3 nmol stable nickel was passed through a column containing aptamer/bead, and a reduction in the concentration of nickel of 95% or more in the liquid passed through column was confirmed by measurement using ICP-OES. Based on the interaction between the FA-N1 aptamer-bead composite and the nickel-containing surrogates, the specificity for nickel was at least three times higher than that for other metal ions such as cobalt and chrome. Examination of the interaction of the aptamer with stable nickel, a non-radioactive isotope, and nickel-63, a radioactive isotope, was performed in order to determine whether it has similar specificity for radioactive and non-radioactive metal ions. In addition, because recovery of more than 99.5% of nickel bound to the aptamer/bead complex was achieved, the aptamer could be reused. Based on these results, we predict that the aptamer, which is capable of removing radioactive nickel through capture of radioactive isotopes of nickel, can be utilized effectively in the effort to reduce liquid nuclear waste. [ABSTRACT FROM AUTHOR]