[en] This proceedings contains articles of Korean Radioactive Waste Society Spring Meeting, 2016. It was held on May 25-27, 2016 Hyundae Hotel in Mokpo, Korea and subject of Korean Radioactive Waste Society Spring Meeting 2016. This proceedings is comprised of 6 sessions. The main topic titles of session are as follows: Spent fuel cycle technology and policy, Decontamination and radioactive waste treatment, High-level radioactive waste disposal, Radiactive waste management, Decontaminatinon and decommission, Radiation safety and environment. (Yi, J. H.)

[en] This new advance nuclear fuel cycle technology technology will produce new types of nuclear materials that are not considered in the current regulations. In particular, the current regulations on physical protection for nuclear materials cannot reflect the characteristics of dirty nuclear materials and also there is inconsistency in a way to characterize the materials. To fill this gap, the regulation needs to be revised to ensure appropriate level of physical protection before the use of the new technology. This study reviews the current regulations, applies them to new technology, and suggests ways to shape risk-informed and performance-based (RIPB) regulatory framework. It is inappropriate to apply the current methods of nuclear material categorization for advanced fuel cycle because different nuclear materials are mixed in a single process. To properly treat the complex composition of nuclear materials, a RIPB approach, which considers both deterministic (quantitative) and probabilistic (qualitative) principles, is required

[en] In this study, Prussian blue-graphene oxide (PB-GO) hydrogel beads were synthesized to remove cesium from aqueous solutions. The PB-GO composites were prepared as PB nanoparticles attached to the surface of multi-layered GO sheets. The PVA-alginate hydrogel beads with PB-GO on their cross-linked structure were prepared and packed in a fixed-bed column system. The effect of various parameters, such as initial cesium concentration, flow rate, bed height, and adsorbent size, on the removal of cesium in the fixed-bed column system was investigated. Furthermore, the Thomas, Adams–Bohart, and Yoon–Nelson models were used to analyze the breakthrough curves using non-linear regression methods. The PB-GO hydrogel beads have a strong potential as an efficient adsorbent for the treatment of wastewater polluted with cesium in continuous operation mode

[en] Pyroprocessing is a spent fuel recycling technology that uses a molten salt system. Tracking the uranium selectively separated is important to pyroporcessing safeguards. In the use of computer models to simulate ER and related mass transport, quantifying the uncertainty and improving the simulating capability of the model is essential. In previous work, we identified a major source of uncertainty in modeling the ER system. The uncertainty stemmed from the dynamic changes in the cathodic surface area during the reaction. Based on those results, this study suggests an approach to improve the model’s ability to simulate the ER. An empirical formula to model the varying surface area of the cathode is to be developed through experimental investigations using the chronoamperometry and the Cottrell equation. The experimental design was developed to enhance our understanding of the growth of uranium on the cathode through time. The resulting formula then is expected to improve the computational modeling capability for ER

[en] Pyroprocessing is technology to recover uranium, transuranic elements, and long-lived fission products from spent nuclear fuel. This technology can considerably reduce the volume and the toxicity of radioactive waste. The optimization of new technology requires repeated experiments that require extremely expensive and dangerous works with nuclear materials. As an alternative, we developed a 2D computational kinetic model for multi-species electrorefining. In this paper, the deposition and dissolution tendency of electrorefining process were studied. Based on these information, this model will contribute to find the optimum condition for high U throughput with high decontamination factor (>100) without other containments by experiments

[en] Spent fuel storage and transport packages store spent fuel assemblies after a certain period of time. nThe package must be evaluate if it removes decay heat which is continuously generated from spent fuel assembly. Fuel assemblies have a array consisting of a number of fuel rod which is composed of fuel pellets and claddings. The properties of axial direction can be obtained by the area-weighted method. And that of radial direction can be calculated by the finite volume method. Therefore, 2D thermal analysis by using ANSYS Fluent v16.2 for the fuel assemblies such as WH OFA 17X17, WH 16X16 and Plus 7 was performed. And the effective thermal conductivities of each assembly which varies depending on temperature are calculated and the design basis fuel was determined. In this study, the effective thermal conductivities are obtained by 2D CFD analysis and these could be applied to the further thermal analysis of spent fuel storage and transport packages

[en] The IAEA SLA(Sates level Approaches) has been applied to KAERI(Korea Atomic Energy Research Institute) nuclear facilities since 2015. The IAEA has carried out the inspection at the KAERI nuclear facilities in accordance with “implementation procedures for safeguards measures for the nuclear facilities at the KAERI-Daejeon site in the ROK” which was agreed with KAERI. The national inspection activities were the same with those of IAEA. In this paper, the major changes of the national inspection are summarized. Also, the status of the national inspection and the internal regulation of the nuclear material accountancy for the nuclear facilities at KAERI are described. In this paper, the major changes of the national inspection in respect of the KAERI nuclear facilities were summarized. The frequency of the national inspection was decreased since the amendment of the Notification of the NSSC on the national inspection. But the national inspection broadened its scope and its implementation procedures and criteria were not clear. So, it is necessary to establish and enhance the national inspection system including the implementing guides and criteria

[en] Migrations of actinides in groundwater is one of the major concerns regarding the underground repository of nuclear wastes. Trivalent actinides including Am(III) are major long-lived radionuclides present in the wastes. It is well-known that chemical interactions of the actinides at the water-solid interface such as minerals and clays are important determinants on the migration rates of the actinides. In order to understand Am(III) adsorption behaviors in the presence of humic acids, we studied a model system of Eu(III), a radio-inactive analogue of Am(III), interacting with silica nanoparticles in the presence of a well-organized small organic ligand, picolinate. Am(III) and Eu(III) share similar chemical behaviors including sorption onto solid phases and thermodynamic properties. Picolinate is bidendate ligand containing carboxylate and a nitrogen donor. Sensitized Ln(III) luminescence by energy transfer from the bound organic ligands is widely employed in probing metal-ligand interactions. Here, we measured the sensitized Eu(III) luminescence to probe the interactions of Eu(III) at a very low concentration with silica in the presence of picolinate using time-resolved laster fluorescence spectroscopy (TRLFS)

[en] Decommissioning is an emerging international issue in the nuclear industry. Termination of the decommissioning authorization involves releasing the facility from the regulatory control for restricted or unrestricted use in the future. Prior to releasing the facility from regulatory control, it must be shown that the site has been sufficiently cleaned up to meet either restricted or unrestricted use in the future. To meet the required standards the site owner has to show that the soil at the facility has been sufficiently cleaned up. To do this one must know the contamination of the soil at the site prior to clean up. This involves sampling that soil to identify the degree of contamination. Regulatory guidelines for site reuse after decommissioning are commonly challenged because the majority of the activity in the soil at or below the limit of detection. RESRAD is a computer model designed to estimate radiation doses and risks from RESidual RADioactive materials. Using additional statistical analyses of contaminated soil after decommissioning is expected to have the following advantages: a better and more reliable probabilistic exposure assessment, better economics (lower project costs) and improved communication with the public. This research will develop an approach that defines an acceptable method for demonstrating compliance of decommissioned NPP sites and validates that compliance. Summary statistic and confidence intervals were compared to conventional methods. Proposed methods were performed using the soil samples from the monazite powder manufacturing plant. The preliminary evaluation shows that the proposed method can be effectively used to provide: the best estimate radioactivity levels at decommissioned NPP site and estimates of uncertainty in the mean value

[en] In the world, electric power production of nuclear power plants (NPP) has been progressed for the past decades. Moreover, electric power production from NPP for continuous energy can be beneficial without producing green-house gas (CO₂). However, all radioactive wastes generated from NPP operation should be securely and safely managed during the nuclear fuel cycle. Especially, the waste includes radioisotope such as ¹²⁹I and ¹³¹I whose half-lives are t_1/2 = 1.57x10⁷ years and t_1/2 = 8.02 days, respectively. These iodine has harmful effects to humans through external and internal exposure which can bring burns to the skin and affect the thyroid gland. Therefore iodine needs to be removed safely. In this study, we used the HY zeolite and Sn ion for capturing iodide from solution waste. HY Zeolite is eco-friendly materials with having high sorption capacity, thermostability, ion exchange, and high pore size as porous material. And Sn ion has chemical interaction with iodide ion and economically affordable. Therefore, the objective of this study is to investigate the capturing radioactive iodine from solution using surface modified HY zeolite with Sn