• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.335-343
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• 2005

The Methodology of burnup calculation with EPMA test set up in this study. The spent fuel from PWR nuclear power plant was used as specimen. This $UO_2$ fuel with $3.2\%$ of enrichment had been irradiated up to 35,000 MWd/MTU(reference data). The burnup is very important factor for nuclear fuel to estimate all fuel behaviors in reactor. To measure amounts of fission products and actinides for the burnup calcualation, chemical analysis (destructive method) has been used but it mattes long experimental time and second radio-wastes. In this study, EPMA test was available to measure amount of fission products. Neodymium is able to be detected and quantified. It can be compared with the results from chemical analysis and ORIGEN-2 code calculation. Concentration of Nd from EPMA test showed good agreement with result of ORIGEN-2 code in the same burnup.

• Applied Microscopy
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• v.35 no.3
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• pp.113-119
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• 2005

The Methodology of burnup calculation with EPMA test set up in this study. The spent fuel from PWR nuclear power plant was used as specimen. This $UO_2$ fuel with 3.2% of enrichment had been irradiated up to 35,000 MWd/MTU. The burnup is very important factor for nuclear fuel to estimate all fuel behaviors in reactor. To measure amounts of fission products and actinides for the burnup calcualation, destructive method analysis has been used but it makes long experimental time and second radio-wastes. In this study, EPMA test was available to measure amount of fission products. Neodymium is able to be detected and quantified. It can be compared with the results from chemical analysis and ORIGEN-2 code calculation. Concentration of Nd from EPMA test showed good agreement with result of ORIGEN-2 code in the same burnup.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.186-190
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• 2014

Nuclear Power Plants require the control ability of chemical condition (pH) because pH control during transient accident such as LOCA makes an able the fission product removal capability to be maintained, stress corrosion cracking of stainless steel equipment to be prevented and the production of hydrogen by aluminum and zinc to be minimized. An NPP is designed to control the pH of containment spray and sump coolant using the spray additives 30% NaOH in the event of loss of coolant accident. In this paper, the pH of sump coolant of an NPP during LOCA was analyzed and the fission products removal constant and decontamination factor were calculated according to Standard Review Plan 6.5.2 related to spray chemical conditions of pH. The calculated pH value of recirculation mode using the computer code corresponds to 8.09~9.67, which meets the chemical environment regulation requirements. The fission product removal capability caused by containment spray system is performed to provide input to radiation analysis.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.1073-1074
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• 2004

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.879-880
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• 2004

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.379-380
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• 2005

• Journal of the Korean Chemical Society
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• v.42 no.2
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• pp.203-208
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• 1998

The photochemical reactivities of 2-halobenzyl phenyl ether, in which 2-halobenzyl moiety are tethered to phenyl moiety by the etheral alkyl linkage, has been studied. In the presence of nitrogen, the photochemical reaction of 2-chlorobenzyl phenyl ether (1) produces mainly phenol and photo-Fries type reaction products, while the corresponding bromo analog 2 produces photocyclization and photoreduced products, along with phenol and photo-Fries type products. The former result implies that since chlorine is bound to the benzyl ring firmly, the rather weaker $CH_{2}-O$ bond of 1 is cleavaged to produce the photo-Fries type product. The latter implies that the photoinduced fission of phenyl-bromine bond of 2 can compete with the fission of $CH_{2}-O$ bond, since the bond energy of phenyl-bromine is lower than that of phenyl-chlorine. Since by the presence of oxygen the formation of phenol is not affected much, the formation of photo-Fries type products is changed a little, and the formations of photocyclization and photoreduced products are affected effectively, a singlet state is involved in the formation of phenol, and both singlet and triplet state may be involved in the formation of photo-Fries type reaction, while a triplet state is involved in the formation of photocyclization and photoreduction products.

• 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.

• Nuclear Engineering and Technology
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• v.48 no.2
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• pp.304-317
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• 2016

An accelerator-driven system consists of a subcritical reactor and a controllable external neutron source. The reactor in an accelerator-driven system can sustain fission reactions in a subcritical state using an external neutron source, which is an intrinsic safety feature of the system. The system can provide efficient transmutations of nuclear wastes such as minor actinides and long-lived fission products and generate electricity. Recently at Kyoto University Research Reactor Institute (KURRI; Kyoto, Japan), a series of reactor physics experiments was conducted with the Kyoto University Critical Assembly and a Cockcrofte-Walton type accelerator, which generates the external neutron source by deuteriu-metritium reactions. In this paper, neutronic analyses of a series of experiments have been re-estimated by using the latest Monte Carlo code and nuclear data libraries. This feasibility study is presented through the comparison of Monte Carlo simulation results with measurements.

• Bulletin of the Korean Chemical Society
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• v.1 no.1
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• pp.35-39
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• 1980

A vacuum ultraviolet photolysis of ethyl bromide was studied in the pressure range of 0.5-19.9 torr and at 123.6 nm krypton resonance line. The pressure effect on the reaction was studied by increasing the reactant pressure and by adding an inert gas, e.g., He. In the observation the monatomic gas is found to be no effect in the reaction. A scavenger effect of the reaction was also performed by adding NO gas as a radical scavenger and was found to be quite efficient to scavenge a radical product $C_2H_6$. The observation of the major reaction product $C_2H_6$ was interpreted in terms of a molecular elimination. Nontheless the decreasing phenomenon of ${\phi}_{C_2H_4}/{\phi}_{C_2H_6}$ with pressure rise was attributed to the existence of the two electronically excited states. One state proceeds to the molecular elimination and the other to carbon-bromine bond fission. The excitation and the decomposition mechanisms between two excited states and the reaction products were interpreted in terms of the first excitation which proceeds the molecular elimination, and the second excitation which resulted from the first excited state by collisional cross over decomposes by carbon-bromine bond fission.