Heavy water (deuterium oxide, D2O) is water in which hydrogen atoms (1H, H), one of the constituent elements of water molecules, have been replaced with deuterium (2H, D), a heavier isotope. Heavy water is used in a variety of industries, including semiconductors, nuclear magnetic resonance, infrared spectroscopy, neutron deceleration, neutrino detection, metabolic rate studies, neutron capture therapy, and the production of radioactive materials such as plutonium and tritium. In particular, heavy water is used as a neutron moderator or coolant in nuclear reactors and as a fuel for nuclear fusion energy, methods for measuring heavy water are becoming increasingly important. There are methods with density, mass spectrometry, and infrared (IR) spectroscopy. In this study, Fourier transform infrared spectroscopy (FT-IR) was used, which is commonly used in IR spectroscopy because of its relatively high analytical sensitivity, low operating costs, and easy online analysis. Heavy water was identified in the range of 2,300-2,600 cm-1 wavenumber (O-D) and the range of 1,200-1,300 cm-1 wavenumber (D-O-D), which are known to be the range with strong infrared absorption. As a result, the linearity of infrared absorbance for each heavy water concentration was confirmed within the relative expansion uncertainty (k=2).

This study demonstrated a rapid and simple method for the determination of seven anions including halides and oxyhalides from the KURT underground water sample by capillary electrophoresis with UV detection. In nuclear waste disposal, some anions such as iodine, selenium, and technetium have been of great concern due to its high mobility and toxicity with a long half-life. It has been needed for a reliable analysis of anionic speciation because the high mobility of anions is easily affected by environmental conditions especially pH and salinity of underground water. Here this project is to develop a fast separation of seven anions including iodide, iodate, and selenite using capillary electrophoresis. The electroosmotic flow (EOF) was suppressed using a poly (ethyleneglycol) -coated capillary (DB-WAX capillary). As a result, anions migrated depending on their mobility under a reverse polarity condition (-15 kV) and the analysis time was within 15 min. UV detection was used at 200 nm. The RSDs for migration time were between 0.7% and 1.3% except for selenite of 5.1%. The RSDs for peak area were obtained between 2.9% and 7.4%. The calibration curves were linear from 10 to 200 mg/L with correlation coefficients greater than 0.9952. The LODs were 7.3, 10.9, 11.3, 12.9, 13.0, 13.9, and 17.4 mg/L for iodide, nitrate, bromide, selenite, bromate, tungstate and iodate. The KURT underground water sample spiked with seven anions at 50 mg/L were analyzed. The recoveries of spiked KURT sample ranged from 93.4% to 99.3%. The proposed method was successfully applied to determine seven anions in underground water sample.

Radiation workers, especially those dealing with Uranium isotopes, can potentially intake Uranium -containing materials through their respiratory and digestive systems. According to the “Regulations on the Measurement and Calculation of Internal Exposure” from Nuclear Safety and Security Commission (NSSC), those who intend to work in or enter the nuclear facilities with a risk of exceeding 2 mSv exposure per year should be examined the internal exposure. However, when it comes to in-vitro bioassay, Uranium intake through drinking water can affect the quantitative analysis. The International Commission on Radiological Protection (ICRP) reported in ICRP Publication 23 (Report on the Task Group on Reference Man) that the reference man excretes Uranium in the urine (0.05-0.5 μg/day) and feces (1.4-1.8 μg/day). Korea Atomic Energy Research Institute (KAERI) set the 90.5 ng/day as the 238U background of workers handing Uranium based on the daily Uranium intake of Koreans. In this research, we examined the possible effects of Uranium in drinking water on internal exposure by analyzing the concentration of Uranium in bottled waters from various water sources sold in the domestic market and a water from the water purifier. The 238U concentration results of analyzing 11 bottled waters and 1 purified water, were ranged from 0 to 10.2 μg/L. All the results were satisfied the standard of 30 μg/L according to “Regulations for Drinking Water Quality Standards and Inspection” enacted by the Ministry of Environment. However, various concentrations were shown depending on the water sources. Assuming that these concentrations of water are consumed by drinking 1 L per day, the internal dose assessment result is 0 to 0.94 mSv. On the other hand, if it is assumed to be inhaled, it can be an overestimated because the dose coefficient of inhalation, Type M is higher than that of ingestion, f1=0.02 which are the values recommended by ICRP Publication 78 (Individual Monitoring for Internal Exposure of Workers) when the Uranium compound is unspecified. In case of two workers at KAERI, the daily excretion of urine was 151 and 120 ng/day respectively in the first quarter monitoring. However after changing the kind of drinking water in the second quarter monitoring, it dropped to 17.4 and 15.4 ng/day respectively. Through this study, it is confirmed that the Uranium background in urine can be analyzed differently depending on the kind of drinking water consumed by each worker. Depending on the Uranium concentration of drinking water, the internal exposure dose assessment can be overestimated or underestimated. Therefore, the Uranium concentration and intake amount according to the kind of drinking water should be considered for in-vitro bioassays of Uranium handlers. Furthermore, if necessary, the Uranium isotope ratio analysis in urine and the handling information should be comprehensively considered. In addition, in order to exclude the effect of intake through the digestive system, replacing the kind of drinking water can be considered. The additional analysis such as in-vivo bioassay and 24 hours urine analysis rather than spot samples can be also recommended.

Copper hexacyanoferrate (Cu-HCF), which is a type of Prussian Blue analogue (PBA), possesses a specific lattice structure that allows it to selectively and effectively adsorb cesium with a high capacity. However, its powdery form presents difficulties in terms of recovery when introduced into aqueous environments, and its dispersion in water has the potential to impede sunlight penetration, possibly affecting aquatic ecosystems. To address this, sponge-type aluminum oxide, referred to as alumina foam (AF), was employed as a supporting material. The synthesis was achieved through a dip-coating method, involving the coating of aluminum oxide foam with copper oxide, followed by a reaction with potassium hexacyanoferrate (KHCF), resulting in the in-situ formation of Cu-HCF. Notably, Copper oxide remained chemically stable, which led to the application of 1, 3, 5-benzenetricarboxylic acid (H3BTC) to facilitate its conversion into Cu-HCF. This was necessary to ensure the proper transformation of copper oxide into Cu-HCF on the AF in the presence of KHCF. The synthesis of Cu-HCF from copper oxide using H3BTC was verified through X-ray diffraction (XRD) analysis. The manufactured adsorbent material, referred to as AF@CuHCF, was characterized using Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). These analyses revealed the presence of the characteristic C≡N bond at 2,100 cm-1, confirming the existence of Cu-HCF within the AF@CuHCF, accounting for approximately 3.24% of its composition. AF@CuHCF exhibited a maximum adsorption capacity of 34.74 mg/g and demonstrated selective cesium adsorption even in the presence of competing ions such as Na+, K+, Mg2+, and Ca2+. Consequently, AF@CuHCF effectively validated its capabilities to selectively and efficiently adsorb cesium from Cs-contaminating wastewater.

Heavy water primary system decontamination technology is essential to reduce worker exposure and improve safety during maintenance and decommissioning of nuclear facilities. Advanced decontamination technology development aims to secure controlled decontamination technologies that can reduce the cost of radiation exposure and dramatically reduce the amount of secondary waste generated when decontaminating large equipment and large-area facilities. We conducted a study to identify candidate corrosion inhibitors through the literature and analyze the degree of corrosion of carbon steel samples. Countries with advanced nuclear technology have developed chemical decontamination technology for the entire nuclear power generation system and applied it to the dismantling and maintenance of nuclear power plants. In the decontamination process, the corrosion oxide film must be removed. If the base metal is corroded by the decontaminant in this process, additional secondary waste is generated and treatment costs increase. Therefore, it is necessary to develop a corrosion inhibitor that inhibits the corrosion of the carbon steel base metal in the decontamination process to generate a secondary waste liquid that is favorable for waste reduction and treatment. In this presentation, a study was conducted to analyze the extent of corrosion on a carbon steel base material and identify candidate materials for corrosion inhibition testing. Samples were analyzed using optical microscopy and EPMA analysis to determine the thickness of the corroded oxide film. EPMA analysis also allowed us to map the elemental distribution of the carbon steel corrosion layer, which we plan to quantify in the future. The candidate materials for organic-based corrosion inhibitor were also selected based on their inhibition mechanism; having high electronegative elements for coordinate covalent bonding at metal surface and hydrophobic nonpolar group for preventing access of corrosive substances.The selection of candidate materials for corrosion inhibition testing was based on the mechanism of the corrosion inhibitor. Organic-based corrosion inhibitors are adsorbed by donor-acceptor interactions between metal surfaces and highly electronegative elements. Corrosion can also be inhibited by arranging hydrophobic nonpolar groups on metal surfaces in the solution direction to prevent access of corrosive substances.

Economical radioactive soil treatment technology is essential to safely and efficiently treat of high-concentration radioactive areas and contaminated sites during operation of nuclear power plants at home and abroad. This study is to determine the performance of BERAD (Beautiful Environmental construction’s RAdioactive soil Decontamination system) before applying magnetic nanoparticles and adsorbents developed by the KAERI (Korea Atomic Energy Research Institute) which will be used in the national funded project to a large-capacity radioactive soil decontamination system. BERAD uses Soil Washing Process by US EPA (402-R-007-004 (2007)) and can decontaminate 0.5 tons of radioactive soil per hour through water washing and/or chemical washing with particle size separation. When contaminated soil is input to BERAD, the soil is selected and washed, and after going through a rinse stage and particle size separation stage, it discharges decontaminated soil separated by sludge of less than 0.075 mm. In this experiment, the concentrations of four general isotopes (A, B, C, and D which are important radioisotopes when soil is contaminated by them.) were analyzed by using ICP-MS to compare before and after decontamination by BERAD. Since BERAD is the commercial-scale pilot system that decontaminates relatively large amount of soil, so it is difficult to test using radioactive isotopes. So important general elements such as A, B, C, and D in soil were analyzed. In the study, BERAD decontaminated soil by using water washing. And the particle size of soil was divided into a total of six particle size sections with five sieves: 4 mm, 2 mm, 0.850 mm, 0.212 mm, and 0.075 mm. Concentrations of A, B, C, and D in the soil particles larger than 4 mm are almost the lowest regardless of before and after decontamination by BERAD. For soil particles less than 4 mm, the concentrations of C and D decreased constantly after BERAD decontamination. On the other hand, the decontamination efficiency of A and B decreased as the soil particle became smaller, but the concentrations of A and B increased for the soil particle below 0.075 mm. As a result, decontamination efficiency of one cycle using BERAD for all nuclides in soil particles between 4 mm and 0.075 mm is about 45% to 65 %.

Hydrogen isotope separation involves the separation of hydrogen, deuterium, tritium, and their isotopologues. It is an essential technology for removing radioactive tritium contamination and for obtaining valuable hydrogen isotope resources. Among various hydrogen isotope separation technologies, water electrolysis technology exhibits a high separation factor. Consequently, the electrolysis of tritiated water is of paramount importance as a tritium enrichment method for treating tritium-contaminated water and for analyzing tritium in environmental samples. More recently, hydroelectrolysis technology, which utilizes proton exchange membranes (PEM) to reduce water inventory, has gained favor over traditional alkaline hydroelectrolysis. Nevertheless, it is crucial to decrease the hydrogen permeability of the PEM in order to mitigate the explosion risk associated with tritium hydrogen electrolysis devices. Additionally, efforts are needed to enhance the hydrogen isotope selectivity of the PEM and optimize the manufacturing process of the membrane-electrode assembly (MEA), thereby improving both hydrogen isotope separation performance and water electrolysis efficiency. In this presentation, we will delve into two key aspects. Firstly, we’ll explore the reduction of hydrogen permeability and the enhancement of the hydrogen isotope separation factor in PEM through the incorporation of 2D nanomaterial additives. Secondly, we’ll examine the influence of various MEAs preparation methods on electrolysis and isotope separation performances. Lastly, we will discuss the effectiveness of the developed system in separating deuterium and tritium.