• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1603-1610
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• 2020

Due to ever-growing advancements in computers and relatively easy access to them, many efforts have been made to develop high-fidelity, high-performance, multi-physics tools, which play a crucial role in the design and operation of nuclear reactors. For this purpose in this study, the neutronic Monte Carlo and thermal-hydraulic sub-channel codes entitled MCNP and COBRA-EN, respectively, were applied for external coupling with each other. The coupled code was validated by code-to-code comparison with the internal couplings between MCNP5 and SUBCHANFLOW as well as MCNP6 and CTF. The simulation results of all code systems were in good agreement with each other. Then, as the second problem, the core of the VVER-1000 v446 reactor was simulated by the MCNP4C/COBRA-EN coupled code to measure the capability of the developed code to calculate the neutronic and thermohydraulic parameters of real and industrial cases. The simulation results of VVER-1000 core were compared with FSAR and another numerical solution of this benchmark. The obtained results showed that the ability of the MCNP4C/COBRA-EN code for estimating the neutronic and thermohydraulic parameters was very satisfactory.

• Nuclear Engineering and Technology
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• v.31 no.3
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• pp.314-327
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• 1999

A subchannel analysis code MATRA applicable to PWRs and ALWRs has been developed to be run on an IBM PC or HP WS based on the existing CDC CYBER mainframe version of COBRA-Rf-1. This MATRA code is a thermal-hydraulic analysis code based on the subchannel approach for calculating the enthalpy and How distribution in fuel assemblies and reactor cores for both steady-state and transient conditions. HATRA has been provided with an improved structure, various functions, and models to give more convenient user environment and to enhance the code accuracy. Among them, the pressure drop model has been improved to be applied to non-square-lattice rod arrays, and the models for the lateral transport between adjacent subchannels have been improved to enhance the accuracy in predicting two-phase flow phenomena. The predictions of MATRA were compared with the experimental data on the flow and enthalpy distribution in some sample rod-bundle cases to evaluate the performance of MATRA. All the results revealed that the predictions of MATRA were better than those of COBRA-IV-I.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.579-584
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• 1997

HP Workstation 및 IBM PC에서 사용 가능한 부수로 해석 코드 MATRA $\alpha$-버전을 개발하였다. 이 코드는 정확도 향상 및 사용자 편리를 위해 COBRA-IV-I코드에 비해 여러가지 기능들이 추가되었으며, 코드의 적용 범위를 신형원자로의 비정방형 집합체 노심에 확장할 수 있도록 압력손실 모형 등이 개선되었다. 또한 이상 유동장에서의 예측 정확도 향상을 위하여 부수로 잔의 횡방향 전달 모형을 개선하였다. 코드의 예측 성능을 평가하기 위해 세 중류의 집합체 유동분포 및 엔탈피 분포 실험 자료와 비교하였으며, 그 결과 기존의 COBRA-IV-I코드보다 향상된 결과를 보였다.

• Nuclear Engineering and Technology
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• v.15 no.4
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• pp.236-247
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• 1983

Analyzed are the the DNBR(Departure from Nucleate Boiling Ratio) sensitivities to variations in various PWR operating parameters utilizing the Korea Nuclear Unit 1(KNU-1) design and operating data. Studied parameters in the analysis are core power level, system pressure, core inlet flow rate, core inlet temperature, enthalpy rise hot channel factor, and axial power peaking factor and axial offset. The calculations are performed using the steady state and transient thermal-hydraulics computer program, COBRA-IV-K, which is the revised version of COBRA-IV-i that has been adapted, partially modified and verified at KAERI. A reference case is established based on the design and operating condition of the KNU-1 reactor core, and this provides a basis for the subsequent sensitivity analysis. From the calculation results it is concluded that the most sensitive parameter in the DNBR thermal design is the coolant core inlet temperature while the axial power peaking factor is the least sensitive.

• Nuclear Engineering and Technology
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• v.31 no.3
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• pp.344-363
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• 1999

A multi-dimensional thermal-hydraulic system analysis code, MARS 1.3.1, has been developed in order to have the realistic analysis capability of two-phase thermal-hydraulic transients for pressurized water reactor (PWR) plants. As the backbones for the MARS code, the RELAP5/MOD3.2.1.2 and COBRA-TF codes were adopted in order to take advantages of the very general, versatile features of RELAP5 and the realistic three-dimensional hydrodynamic module of COBRA-TF. In the MARS code, all the functional modules of the two codes were unified into a single code first. Then, the source codes were converted into the standard Fortran 90, and then they were restructured using a modular data structure based on "derived type variables" and a new "dynamic memory allocation" scheme. In addition, the Windows features were implemented to improve user friendliness. This paper presents the developmental work of the MARS version 1.3.1 including the hydrodynamic model unification, the heat structure coupling, the code restructuring and modernization, and their verifications.their verifications.

• Journal of The Korean Society of Clinical Toxicology
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• v.20 no.1
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• pp.22-24
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• 2022

Elapid snakes have neurotoxic venom which causes diverse neuroparalytic manifestations, including fatal respiratory failure. In South Korea, since elapid snakebites are very rare, the cobra antivenom, which is effective against neurotoxicity, was only introduced recently. Most physicians in South Korea have little experience in the treatment of patients who have been bitten by elapid snakes. A 19-year-old man was brought to the emergency department with sudden diplopia, 1 hour after a snakebite on the left 2nd finger. The patient presented with drowsiness and complained of mild dizziness and binocular diplopia. After 1 hour, he had sudden onset of dyspnea and dysphagia and appeared to be agitated. He was immediately intubated and received mechanical ventilation as he was unable to breathe on his own. A total of 2.5 mg of neostigmine diluted with normal saline was slowly infused, and 1 vial of cobra antivenom was infused for an hour, 5 times every 2 hours, for a total of 5 vials. He slowly recovered self-breathing; on the 3rd day of hospitalization, he showed tolerable breathing and was extubated. He was discharged without any neurological deficits or other complications.

• Journal of Korea Water Resources Association
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• v.52 no.4
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• pp.301-312
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• 2019

The importance of the dual drainage system model has increased as the urban flood damage has increased due to the increase of local storm due to climate change. The dual drainage model is a model for more accurately expressing the phenomena of surface flow and conduit flow. Surface runoff and pipe runoff are analyzed through the respective equations and parameters. And the results are expressed visually in various ways. Therefore, inundation analysis results of dual drainage model are used as important data for urban flood prevention plan. In this study, the applicability of the COBRA model, which can be interpreted by combining the dual drainage system with the natural watershed and the urban watershed, was investigated. And the results were compared with other dual drainage models (XP-SWMM, UFAM) to determine suitability of the results. For the same watershed, the XP-SWMM simulates the flooding characteristics of 3 types of dual drainage system model and the internal flooding characteristics due to the lack of capacity of the conduit. UFAM showed the lowest inundation analysis results compared with the other models according to characteristics of consideration of street inlet. COBRA showed the general result that the flooded area and the maximum flooding depth are proportional to the increase in rainfall. It is considered that the COBRA model is good in terms of the stability of the model considering the characteristics of the model to simulate the effective rainfall according to the soil conditions and the realistic appearance of the flooding due to the surface reservoir.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1998.10a
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• pp.361-364
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• 1998

• Journal of Pharmacopuncture
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• v.6 no.2
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• pp.165-177
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• 2003

The study was carried out to investigate the researches of Snake which was published papers in the TOXlCON(1990-2000), one of the most famous Journal of toxicology. And the results were as follows : 1. The number related with Snake is 195papers. 2. There were great papers related wih Cobra, and next is Tigris, Viper, etc. 3. There were great papers related wih protein in the composition of snake venom. 4. There were great papers related wih neurotoxin in the research of poisonous character. 5. There were great papers related wih Viper according to the anticoagulation. 6 Eight papers were published to study the immune response of snake venom. 7. The papers of molecular study of snake venom were seven. 8. The papers of anti-snake venom study were three.

• Archives of Pharmacal Research
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• v.20 no.1
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• pp.13-16
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• 1997

The cytotoxicity of animal venoms (snakes, insects and marine animals) was measured against SNU-1 (stomach cancer cells) by dye uptake assay (MTT method). And also L-amino acid oxidase (AAO) activity of the venoms was compared. Among them, the venom from Ophiophagus hannah (king cobra) showed a strong AAO activity as well as a high potent cytotoxicity. Cytotoxic protein having a AAO was then partially purified by HPLC-GPC and two fractions (Fr. I and Fr. II) were collected. The $IC_{50}$ values of Fr. I and Fr. II were 0.19 ${\mu}g/ml$ and 1.36 ${\mu}g/ml$, respectively. The results suggested that the cytotoxicity of king cobra venom may be due to its AAO activity.