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[en] The 10-year joint study between Korea and U. S. is on going in order to investigate the feasibility of the pyro processing technology. The viable results of this study will drive KAERI to construct the pyro processing demonstration facility. For the optimized facility design and construction, the operation and maintenance data of the pyro process need to be analyzed with the discrete event simulation and modeling methodology. The following studies were performed in 2012 to establish the basis of the modeling and simulation. Ο The general of discrete event simulation Ο Fundamentals of the Arena software Ο Basic modeling and simulation technique by using Arena Ο Statistical analysis methodology of the results of pyro process simulation Based on this study, the technological basis of the modeling and simulation was developed, and basic design and operation and maintenance data of the pyro process facility will be acquired with the statistical analysis of the simulation results
[en] The simultaneous removal of cationic and anionic radiotoxic nuclides, such as Cs137 and I129, from aqueous solutions has been studied. As an adsorbent material, the mixture of activated carbon and chabazite zeolite was used. Chabazite zeolite is selected due to its high selectivity for Cs+, and activated carbon due to its strong affinity for anions. Taking into account release rates of these nuclides from defected fuel rods as well as the inventories of radiotoxic cesium and iodine isotopes at discharge, it would be the most conservative assumption that the concentration of I- is at most 1% of that of Cs+ in spent fuel storage basin water or low-level liquid wastes. Based upon this assumption, the mixture of 7:3 activated carbon-chabazite ratio in weight was found optimum for this reference concentration ratio f Cs+ and I-. Using this mixture of activated carbon and chabazite, he amount adsorbed until breakthrough points were estimated to be 0.62x10-1 mol/kg for Cs+ and 0.58x10-3 mol/kg for I-. This conforms to the mole ratio of them in the feed solution. In order to investigate the adsorption mechanism and process conditions, equilibrium and kinetic studies as well as the column study were carried out. Surface analyses (SEM-EDAX,EPMA surface image scanning, and XPS) of chabazite and activated carbon show that the adsorption mechanisms of Cs+ and I- is not due to the formation of any precipitates or crystallines at the surfaces of chabazite and activated carbon. From the equilibrium study, it was noticed hat Cs+ specifically adsorbed onto the activated carbon surface caused a synergy effect on the adsorption of I-. This phenomenon was experimentally verified with the column runs according to the packing types of a fixed bed. The effect of background electrolytes, namely Na+ and Cl-,on the Cs+ isotherm s minute over the whole range of equilibrium concentration, whereas that on the I- isotherm gets greater as the equilibrium concentration gets lower. Therefore, the dynamic model for Cs+ is proposed based on the single-component isotherm and surface diffusion, whereas for I- based on competitive adsorption and surface diffusion. The lumped effective mass-transfer parameters of dedicated nuclides, external film mass transfer coefficients (kf) and the effective intraparticle surface diffusion coefficients (Ds), was derived from the experimental concentration histories by an iterative two-parameter search technique predicted on the minimization of the sum of squares of residuals. With estimated kf and Ds, the adsorption behaviors in a batch reactor provided acceptable predictions for each nuclide. The breakthrough behaviors in a column were also predicted satisfactorily by he proposed dynamic models and estimated parameters. Overall, adsorption characteristics investigated in the dedicated adsorption system will provide the valuable information on the practical implementation f the mixed adsorbent. How-ever, the relatively inferior predictions for aqueous iodine imply that more in-depth studies will be required on its adsorption mechanism and the proposed mass transfer model
[en] The R and D status of the nuclear fuel cycle beckoned was investigated and analyzed for Korea and overseas nuclear countries. The technical achievement and future plan of Korea were outlined, and up-to-date R and D status and strategies of overseas nuclear countries were investigated and analyzed. Ο United States Ο France and European Union Ο Japan Ο Russia Ο China And the recent trend of the multilateral approach in the nuclear fuel cycle backoned was arranged
[en] The irradiation tests of the DUPIC fuel using a rig have been carried out at the HANARO research reactor of KAERI in order to analyze the in-core performance. For this study, the non-instrumented rig was developed in 1998, and 4 separate irradiation tests for the DUPIC fuel were performed successfully from 1999 to 2002. In 2004, the instrumented irradiation test was performed to measure the centerline temperature of the DUPIC fuel. The measured maximum temperature of the DUPIC fuel rods was estimated to be 1,100 C at the maximum linear element rating of 38 kw/m. The discharge burn-up was calculated to be 2,133 MWd/tHM. The post irradiation examination results show that a rapid power change during the start-up of HANARO caused large cracks along the radial direction of the instrumented DUPIC pellet. (Author)
[en] Technical assistance was carried out to develop nitride filler for thermally conductive epoxy molding compounds. Carbothermal reduction method was used to fabricate silicon nitride powder from mixtures of silica and graphite powders. Microstructure and crystal structure were observed by using scanning electron microscopy and x-ray diffraction technique. Thermal properties of epoxy molding compounds containing silicon nitride were measured by using laser flash method. Fabrication process of silicon nitride nanowire was developed and was applied to a patent.
[en] There are three main categories in this report : 1)Basement construction of measurement standardization for nuclear material thermal property, 2) Reliability evaluation of measurement instrument, and 3) Standardization and industrial propagation
[en] To perform the evaluation of various fuels in the nuclear reactors, not only the mechanical properties but also thermo-physical properties are required as one of most important inputs for fuel performance code system. The main objective of this study is to make a database system for fuel thermo-physical properties and a PC-based hardware system has been constructed for ease use for the public with visualization such as web-based server system. This report deals with the hardware and software which are used in the database server system for nuclear fuel thermo-physical properties. It is expected to be highly useful to obtain nuclear fuel data without such a difficulty through opening the database of fuel properties to the public and is also helpful to research of development of various fuel of nuclear industry. Furthermore, the proposed models of nuclear fuel thermo-physical properties will be enough utilized to the fuel performance code system
[en] Project of the Atomic Energy Technology Record is the project that summarizes and records whole process, from the background to the performance, of each category in all fields of nuclear science technology which have been researched and developed at KAERI. This project includes development of Data And Documents Advanced Management System(DADAMS) to collect, organize and preserve various records occurred in each research and development process. In addition, it means the whole records related to nuclear science technology for the past, present and future. This report summarizes research contents and results of 'Project of Atomic Energy Technology Record'. Section 2 summarizes the theoretical background, the current status of records management in KAERI and the overview of this project. And Section 3 to 5 summarize contents and results performed in this project. Section 3 is about archiving of core atomic energy technology, Section 4 summarizes about the operation of DADAMS, Section 5 summarizes about collecting, organizing and digitalizing of research records, in particular, we built a gateway service of Project of Atomic Energy Technology Record to increase the utilization of technology records by field.
[en] In this research, real-time, direct, and quantitative measurement and analysis for fissile material in spent fuel and recycled fuel including TRU will be performed by developing SDTS(slowing-down time spectrometer) system. Prior to develop SDTS, analysis of domestic and international technology development for measuring fissile materials, evaluation of systematic elements for pre-conceptual design and feasibility study of fissile analysis and applicability of fissile analysis for DUPIC fuel and uranium isotopes from pyro-processing is performed. Using Monte Carlo simulation, MCNPX code, neutron slowing down medium, analysis of geometry, source position, self-shielding effect, detector impurity effect, detector gamma contribution, neutron cut-off effect and shielding calculation were done for the pre-conceptual design of SDTS system, generating basic raw data, and basic assessments of SDTS system. The collection of data for neutron source generators is performed in order to make advanced neutron source generator for LSDTS. Based on the collected data, electron linear accelerator was decided and the new target for making neutron is devised using Tantalum. From the results, the preconceptual design for SDTS system was obtained
[en] The flow characteristic of the irradiation test rigs has been investigated by using a commercial CFD code, CFX-5.7(Ansys Inc.). The test rigs had been developed and fabricated to irradiate the DUPIC mini-elements in the HANARO research reactor of the Korea Atomic Energy Research Institute. First, the fluid flow through the DUPIC-2 test rig was calculated and compared with an experimental data. The computed pressure drops across the DUPIC-2 test rig match well with the experimental data. Then, a CFD analysis has been performed for the fluid flow through the newly-designed DUPIC-6 test rig. As results of the prediction, it is estimated that the mass flow rate is 8.0 kg/s under the pressure drop across the DUPIC-6 test rig of 215.5 kPa. The corresponding the maximum vibration displacement is expected to be around 50 □m, which satisfies the license limit with large margin