• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2011년도 학술발표회
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• pp.250-250
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• 2011

지정학적으로 3면이 바다로 접하고 있는 우리나라 해안가 주변의 원자력발전소는 관류형 냉각 방식(Once-through cooling System)을 채택하고 있기에, 이 계통을 통과한 냉각수는 주변해역으로 흘러들어가 주변 환경에 영향을 줄 수 있다. 또한 동해 주변 인접국들의 활발한 원자력 이용과 방사능 물질의 수송 등으로 인해 방사능 사고 위험이 증대됨에 따라 동해 원전 주변의 해양방사성물질 거동에 대한 필요성이 제기되고 있다. 이에 따라 동해의 해양환경을 조사 분석하여 해역에서의 오염 물질의 거동 파악이 중요하고, 산업시설 주변 연안의 오염물 이동 및 해석을 위해 오염물의 시 공간적으로 농도를 추정하는 것이 중요한 사항이다. 따라서 본 연구에서 수직 수평적으로 2차원 및 3차원화가 용이한 EFDC 모델을 사용하였다. 국립해양조사원에서 발간하는 DC103의 수치해도를 이용하여 모델영역은 동서방향으로 171km, 남북방향으로 235km로 설정하고, 격자간격은 $1km{\times}1km$의 정방향 격자를 사용하여 동해 월성 주변의 조위 시계열 검증 및 조화분석을 통한 검증을 실시한 결과 관측한 결과와 양호한 재현성을 나타내었다. 또한 국립수산과학원에서 제공되고 있는 년별 수온, 염분 자료 등의 해양환경과 지형적 특성을 고려하여 오염 물질의 이동 경로를 파악함으로써 사고시 피해를 줄이고자 한다.

• 방사성폐기물학회지
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• 제14권1호
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• pp.11-19
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• 2016

This paper focuses on the estimation of durability and service-life of reinforced concrete structures in Wolsong Low- and intermediate-level wastes Disposal Center (WLDC) in Korea. There are six disposal silos located in the saturated environment. The silo concrete is degraded due to reactions with groundwater and chemical attacks, and finally it will lose its properties as a transport barrier. The infiltration of sulfate and magnesium, leaching of potassium hydroxide, and chlorine induced corrosion are the most significant factors for degradation of reinforced concrete structure in underground environment. From the result of evaluation of the degradation time for each factor, the degradation rate of the reinforced concrete due to sulfate and magnesium is $1.308{\times}10^{-3}cm/yr$, and it is estimated to take 48,000 years for full degradation while potassium hydroxide is leached in depth of less than 1.5 cm at 1,000 years after the initiation of degradation. In case of chlorine induced corrosion, it takes 1,648 years to initiate corrosion in the main reinforced bar and 2,288 years to reach the lifetime limit of the structural integrity, and thus it is evaluated as the most significant factor.

• 설비공학논문집
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• 제15권3호
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• pp.239-245
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• 2003

In the nuclear power plant, emergency core coolant system (ECCS) is furnished at reactor coolant system (RCS) in order to cool down high temperature water in case of emergency. However, in this coolant system, thermal stratification phenomenon can occur due to coolant leaking in the check valve. The thermal stratification produces excessive thermal stresses at the pipe wall so as to yield thermal fatigue crack (TFC) accident. In the present study, effects of turbulence penetration on the thermal stratification into T-branches with square cross-section in the modeled ECCS are analysed numerically. $textsc{k}$-$\varepsilon$ model is employed to calculate the Reynolds stresses in momentum equations. Results show that the length and strength of thermal stratification are primarily affected by the leak flow rate of coolant and the Reynolds number of the main flow in the duct. Turbulence penetration into the T-branch of ECCS shows two counteracting effects on the thermal stratification. Heat transport by turbulence penetration from the main duct to leaking flow region may enhance thermal stratification while the turbulent diffusion may weaken it.

• 한국태양에너지학회 논문집
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• 제22권2호
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• pp.27-32
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• 2002

The Characteristics of heat transport in the heat pipe with a double vapor path and different kinds of the working fluid were investigated experimentally. The Experiment was carried out with acetone/ethanol. ethanol/ethanol. and in the aluminium container of the double vapor path. Performance measurements can be operated at the high level by 24000 w/m2 heat flux in the 1000mm evaporator. They are each estimated at the high temperature and experimentally reviewed the characteric of the heat rejection. The results shew that they are stably operated under each condition and the fluid was complemented each other at the fluid's experiment and brought about the extention of operating temperature. In this study, The reliable basic data obtained by the teste in the heat pipe with a double vapor path can be used for thermal design, manufacture, and production etc.

• Journal of Radiation Protection and Research
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• 제41권4호
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• pp.350-353
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• 2016

Background: Various characteristics such as size distribution, chemical component and radio-activity have been analyzed for radioactive aerosols released from Fukushima Daiichi Nuclear Power Plant. Measured results for radioactive aerosols suggest that the potential transport medium for radioactive cesium was non-sea-salt sulfate. This result indicates that cesium isotopes would preferentially attach with sulfate compounds. In the present work the attachment behavior of fission products to aqueous solution aerosols of sodium salts has been studied using a generation system of solution aerosols and spontaneous fission source of $^{248}Cm$. Materials and Methods: Attachment ratios of fission products to the solution aerosols were compared among the aerosols generated by different solutions of sodium salt. Results and Discussion: A significant difference according as a solute of solution aerosols was found in the attachment behavior. Conclusion: The present results suggest the existence of chemical effects in the attachment behavior of fission products to solution aerosols.

• 한국수소및신에너지학회논문집
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• 제27권6호
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• pp.660-669
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• 2016

A fluorinated-sulfonated, hydrophobic-hydrophilic copolymer was planed subsequently synthesized using typical nucleophilic substitution polycondensation reaction. A novel AB and ABA (or BAB) block copolymers were synthesized using sBCPSBP (sulfonated 4,4'-bis[4-chlorophenyl)sulfonyl]-1,1'-biphenyl), DHN (1,5-dihydroxynaphthalene), DFBP (decafluorobiphenyl) and HFIP (4,4'-hexafluoroisopropylidenediphenol). All block copolymers were easily cast and made into clear films. The structure and synthesized copolymers and corresponding membranes were analyzed using GPC (gel permeation chromatography), $^1H$-NMR ($^1H$ nuclear magnetic resonance) and FT-IR (Fourier transform infrared). TGA (Thermogravimetric analysis) and DSC (differential scanning calorimetry) analysis showed that the prepared membranes were thermally stable, so that elevated temperature fuel cell operation would be possible. Hydrophobic/hydrophilic phase separation and clear ionic aggregate block morpology was confirmed in both triblock and diblock copolymer in AFM (atomic force microscopy), which may be highly related to their proton transport ability. A sulfonated BAB triblock copolymer membrane with an ion-exchange capacity (IEC) of 0.6 meq/g has a maximum ion conductivity of 40.3 mS/cm at $90^{\circ}C$ and 100% relative humidity.

• Journal of Radiation Protection and Research
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• 제17권2호
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• pp.49-59
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• 1992

이온 또는 착화된 상태의 방사성핵종의 이동에 대한 착화제의 영향을 조사하기 위하여 새로운 모델이 제시되었다. 착화된 방사성핵종의 이동거동은 착화제와 착화된 방사성핵종의 열화를 포함하는 대류-확산 이동방정식에 의해 해석되었다. 이 수학적 모델은 해석적인 방법 에 의해 구해졌으며 지연요소를 조사함으로써 분석되었다. 계산결과들은 감소된 지연요소에 의해 착화된 방사성핵종의 이동속도가 이온형태의 방사성핵종보다 매우 빠름을 보여주었다. 따라서 원자력발전소로부터의 착화제의 발생과 환경으로의 유출을 감소시킬 수 있는 새로운 구제책이 필요하다고 하겠다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제20권4호
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• pp.259-262
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• 2017

Mitochondria play essential role in eukaryotic cells including in the oxidative phosphorylation and generation of adenosine triphosphate via the electron-transport chain. Therefore, defects in mitochondrial DNA (mtDNA) can result in mitochondrial dysfunction which leads to various mitochondrial disorders that may present with various neurologic and non-neurologic manifestations. Mutations in the nuclear gene polymerase gamma (POLG) are associated with mtDNA depletions, and Alpers-Huttenlocher syndrome is one of the most severe manifestations of POLG mutation characterized by the clinical triad of intractable seizures, psychomotor regression, and liver failure. The hepatic manifestation usually occurs late in the disease's course, but in some references, hepatitis was reportedly the first manifestation. Liver transplantation was considered contraindicated in Alpers-Huttenlocher syndrome due to its poor prognosis. We acknowledged a patient with the first manifestation of the disease being hepatic failure who eventually underwent liver transplantation, and whose neurological outcome improved after cocktail therapy.

• 방사성폐기물학회지
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• 제19권1호
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• pp.9-27
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• 2021

As an example of research activities in decontamination for decommissioning, new data are presented on the options for corrosion layer dissolution during the decommissioning decontamination, or persulfate regeneration for decontamination solutions re-use. For the management of spent decontamination solutions, new method based on solvent extraction of radionuclides into ionic liquid followed by electrodeposition of the radionuclides has been developed. Fields of applications of composite inorganic-organic absorbers or solid extractants with polyacrylonitrile (PAN) binding matrix for the treatment of liquid radioactive waste are reviewed; a method for americium separation from the boric acid containing NPP evaporator concentrates based on the TODGA-PAN material is discussed in more detail. Performance of a model of radionuclide transport, developed and implemented within the GoldSim programming environment, for the safety studies of the LLW/ILW repository is demonstrated on the specific case of the Richard repository (Czech Republic). Continuation and even broadening of these activities are expected in connection with the approaching end of the lifespan of the first blocks of the Czech NPPs.

• 방사성폐기물학회지
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• 제18권4호
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• pp.421-437
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• 2020

This study provides an assessment on a proposed method for separation of cesium, strontium, and barium using electrochemical reduction at a liquid bismuth cathode in LiCl-KCl eutectic salt, investigated via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS). CV studies were performed at temperatures of 723-823 K and concentrations of the target species up to 4.0wt%. Redox reactions occurring during potential sweeps were observed. Concentration of BaCl2 in the salt did not seem to influence the diffusivity in the studied concentration range up to 4.0wt%. The presence of strontium in the system affected the redox reaction of lithium; however, there were no distinguishable redox peaks that could be measured. Impedance spectra obtained from EIS methods were used to calculate the exchange current densities of the electroactive active redox couple at the bismuth cathode. Results show the rate-controlling step in deposition to be the mass transport of Cs+ ions from the bulk salt to the cathode surface layer. Results from SEM-EDS suggest that Cs-Bi and Sr-Bi intermetallics from LiCl-KCl salt are not thermodynamically favorable.