• Journal of the Korean Society of Systems Engineering
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• v.13 no.2
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• pp.34-41
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• 2017

The Pyro project, one of the large national R&D project to construct Korea Advanced Pyroprocessing Facility (KAPF), which has many goals such as development of pyro technology and process equipment, design of equipment and facility, construction, and test operation, is now under research and development. To reduce uncertainty and risk of such complex project, the technical management processes in systems engineering standards and NASA handbook were reviewed, and then the ten common technical management processes were selected for the large national R&D project to meet its goal successfully. And the essential technical management processes were finally suggested for Pyro project in consideration of current situation of the project.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.02a
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• pp.150-164
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• 2004

According to the Korean long-term plan for nuclear technology development, KAERI is conducting a few R&D projects related to the proliferation-resistant back-end fuel cycle. The R&D activities for the back-end fuel cycle are reviewed in this work, especially focusing on the study of the partitioning and transmutation(P&T) of long-lived radionuclides. The P&T study is currently being carried out in order to develop key technologies in the areas of partitioning and transmutation. The partitioning study is based on the development of pyroprocessing such as electrorefining and electrowinning because they can be adopted as proliferation-resistant technologies in the fuel cycle. In this study, various behaviors of the electrodeposition of uranium and rare earth elements in the LiCl-KCl electrorefining system have been examined through fundamental experimental work. As for the transmutation system, KAERI is studying the HYPER (HYbrid Power Extraction Reactor), a kind of subcritical reactor which will be connected with a proton accelerator. Up to now, a conceptual study has been carried out for the major elemental systems of the subcritical reactor such as core, transuranic fuel, long-lived fission product target, and the Pb-Bi cooling system, etc. In order to enhance the transmutation efficiency of the transuranic elements as well as to strengthen the reactor safety, the reactor core was optimized by determining its most suitable subcriticality, the ratio of height/diameter, and by introducing the concepts of optimum core configuration with a transuranic enrichment as well as a scattered reloading of the fuel assemblies.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2
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• pp.169-177
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• 2020

Here, the stability of stainless steel 316 (SS-316) was investigated to identify its applicability in the oxide reduction process, as a component in related equipment, to produce a complicated gas mixture composed of O₂ and Cl₂ under an argon (Ar) atmosphere. The effects of the mixed gas composition were investigated at flow rates of 30 mL/min O₂, 20 mL/min O₂ + 10 mL/min Cl₂, 10 mL/min O₂ + 20 mL/min Cl₂, and 30 mL/min Cl₂, each at 600℃, during a constant argon flow rate of 170 mL/min. It was found that the corrosion of SS-316 by the chlorine gas was suppressed by the presence of oxygen, while the reaction proceeded linearly with the reaction time regardless of gas composition. Surface observation results revealed an uneven surface with circular pits in the samples that were fed mixed gases. Thermodynamic calculations proposed the combination of Fe and Ni chlorination reactions as an explanation for this pit formation phenomenon. An exponential increase in the corrosion rate was observed with an increase in the reaction temperature in a range of 300 ~ 600℃ under a flow of 30 mL/min Cl₂ + 170 mL/min Ar.

• Nuclear Engineering and Technology
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• v.42 no.2
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• pp.183-192
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• 2010

An electrochemical reduction of a mixture of metal oxides was conducted in a LiCl molten salt containing 3 wt% $Li_2O$ at $650^{\circ}C$. The oxide reduction was carried out by applying a current to an electrolysis cell, and the $Li_2O$ concentration was analyzed during each run. The concentration of $Li_2O$ in the electrolyte bulk phase gradually decreases according to Faraday's law due to a slow diffusion of the $O^{2-}$ ions. A hindrance effect of the unreduced metal oxides was observed for the reduction of the uranium oxide. Cs, Sr, and Ba of high heat-load fission products were diffused into and accumulated in the salt phase as predicted with thermodynamic consideration.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2226-2230
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• 2005

The Advanced Spent Fuel Conditioning Process (ACP), which is a pre-disposal treatment process for spent fuel is being developed at the Korea Atomic Energy Research Institute (KAERI). The ACP equipment is operated in an intense radiation field as well as in a high temperature. Thus, the equipment is designed in consideration of the remote handling and maintenance. This paper describes a Bridge Transported Bilateral Force-Reflecting Servo-Manipulator (BTSM) system, which is being developed to overcome the limitation of access that is a drawback of the mechanical Master-Slave Manipulators (MSMs), which are mounted on the ACP hot cell wall for the operation and the maintenance of the ACP equipment. The BTSM system was manufactured and temporally installed at the mockup to test its performance. The manufactured BTSM system will be installed at the ACP hot cell on June 2005 after the accomplishment of the performance test. The BTSM system consists of four components: a transporter with a telescoping tubeset, a slave manipulator, a master manipulator, and a remote control system. This system will highly increase the volume of coverage for the operation and maintenance of the ACP equipment.

• Nuclear Engineering and Technology
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• v.44 no.7
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• pp.767-772
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• 2012

In support of optimizing electrorefining technology for treating spent nuclear fuel, lithium drawdown has been investigated for separating actinides from molten salt electrolyte. Drawdown reaction selectivity is a major issue that requires investigation, since the goal is to remove actinides while leaving the fission products and other components in the salt. A series of lithium drawdown tests with surrogate fission product chlorides was run to obtain selectivity data with non-radioactive salts, develop a predictive model, and draw conclusions about the viability of using this process with actinide-loaded salt. Results of tests with CsCl, $LaCl_3$, $CeCl_3$, and $NdCl_3$ are reported here. Equilibrium was typically achieved in less than 10 hours of contact between lithium metal and molten salt under well-stirred conditions. Maintaining low oxygen and water impurity concentrations (<10 ppm) in the atmosphere was observed to be critical to minimize side reactions and maintain stable salt compositions. An equilibrium model has been formulated and fit to the experimental data. Good fits to the data were achieved. Based on analysis and results obtained to date, it is concluded that clean separation between minor actinides and lanthanides will be difficult to achieve using lithium drawdown.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.06a
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• pp.73-73
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• 2009

There are many factors to evaluate nuclear fuel cycle such as safety, public acceptance, economics, etc.. Transparency, proliferation, environment issues, public acceptance and safety are essential to expansion of nuclear industry and proliferation resistance is one of key constraints in the deployment of advanced nuclear energy systems. Proliferation resistance is being considered as one of the most important factors in assessing advanced and innovative nuclear systems. IAEA defmes proliferation resistance as characteristics of nuclear energy system that impedes the diversion or undeclared production of nuclear material [1]. Barriers to proliferation is consist of intrinsic and extrinsic barriers(institutional measures). Intrinsic barriers are characterized in material barriers and technical barriers in general. Material barriers is intrinsic, or inherent, qualities of materials that reduce the inherent desirability or attractiveness of the material as an explosive. Isotopic, chemical, radiological, mass and bulk, detectability barriers are considered as material barriers attributes [2]. Proliferation resistance is examined for several nuclear fuel cycles based on previous study which is focused on the intrinsic barriers [3-4]. Pyroprocessing and DUPIC are considered as reprocessing technologies in Korea and the PWR direct disposal is considered. Comparative assessments of the proliferation attributes and merits of different fuel cycle systems will be performed and the optimal back-end fuel cycle and strategy will be proposed.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11b
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• pp.280-289
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• 2005

A pyrochemical process has been introduced and utilized so that the transmutation of spent PWR fuel in PEACER can produce mainly low and intermediate level waste for near surface disposal. Major radioactive nuclides from PEACER pyroprocessing are composed of TRU and LLFP. In this study, the requirement for the final waste from PEACER is evaluated based on the methodology for establishment of waste acceptance criteria. Also, sensitivity analysis for several input parameters is conducted in order to determine acceptable decontamination factor (DF) and LLFP removal efficiency and to find out input parameter that extremely have an effect on DE As a result of the study, LLFP removal efficiency, especially Sr-90 and Tc-99, is proved to be a major nuclide which contributes to annual dose by human intrusion scenario rather than TRU DF. More than $98.5\%$ of LLFP have to be removed to meet below dose constraint within the DF more than 5.0E+03. Besides, because of the relative short half-life of Sr-90, the increasing of the institutional control period is recommended for most important input parameter to determine DF.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.3
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• pp.415-420
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• 2020

Strontium is known as a salt-soluble element during the electrolytic oxide reduction (EOR) process. The chemical behavior of SrO during EOR was investigated via thermodynamic calculations to provide quantitative data on the chemical status of Sr. To achieve this, thermodynamic calculations were conducted using HSC chemistry software for various EOR conditions. It was revealed that SrO reacts with LiCl salt to produce SrCl₂, even in the presence of Li₂O, and that the ratio of SrCl₂ depends on the initial concentration of Li₂O dissolved in LiCl. It was found that SrO reacts with Li to produce Sr during EOR and that the reduced Sr reacts with LiCl salt to produce SrCl₂. As a result, the proportions of metallic forms were lower in Sr than in La and Nd under various EOR conditions. The thermodynamic calculations indicated that the three chemical forms of SrO, SrCl₂, and Sr co-exist in the EOR system under an equilibrium with Li, Li₂O, and LiCl.

• Nuclear Engineering and Technology
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• v.46 no.4
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• pp.489-500
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• 2014

In this study, remote handling strategies for a large-scale argon cell facility were considered. The suggested strategies were evaluated by several types of field test. The teleoperation tasks were performed using a developed remote handling system, which enabled traveling over entire cell area using a bridge transport system. Each arm of the system had six DOFs (degrees of freedom), and the bridge transport system had four DOFs. However, despite the dexterous manipulators and redundant monitoring system, many operators, including professionals, experienced difficulties in operating the remote handling system. This was because of the lack of a strategy for handling the installed camera system, and the difficulty in recognizing the gripper pose, which might fall outside the FOV (field of vision) of the system during teleoperation. Hence, in this paper, several considerations for the remote handling tasks performed in the target facility were discussed, and the tasks were analyzed based on ergonomic factors such as the workload. Toward the development of a successful operation strategy, several ergonomic issues, such as active/passive view of the remote handling system, eye/hand alignment, and FOV were considered. Furthermore, using the method for classifying remote handling tasks, several unit tasks were defined and evaluated.