• Journal of the Korea Society for Simulation
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• v.26 no.3
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• pp.1-11
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• 2017

Blast injuries in a compartment are investigated, and the effects of obstacles on blast injury are particularly analyzed by comparing injuries in the compartments with or without protruding obstacles inside. Even if blast pressure profile tends to be complicated in a confined space unlike in open field, it can be obtained in a relatively short time by using some empirical fast running models for simple confined spaces. However, a finite element method should be employed to obtain blast pressure profiles in a case with obstacles in confined spaces, because the obstacles heavily disturb blast waves. On the other hand, Axelsson SDOF(Single degree of freedom) model and ASII(Adjusted severity of injury index) injury level are employed to estimate blast injury in compartments, because the usual pressure-impulse injury criterion based on the ideal Friedlander waves in open the field cannot be applied to personnel in a confined space due to complexity of blast waves inside. In cases with obstacles, chest wall velocity was reduced by 26 to 76 percent(%) and the personnel injury in the compartment caused by blast was also reduced.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.617-622
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• 1997

격납건물내 소격실에서의 수소혼합 정도를 파악하고 격실내 균일한 혼합을 좌우하는 인자의 영향을 분석하기 위하여 소규모 혼합실험을 수행했다. 본 연구에서는 해석적으로 수립된 3차원 혼합 모델의 검증을 위하여 3차원 모사가 가능하도록 실험 장치를 구성하였다. 격납용기 내에서 수소 생성의 주원인이 되는 노심으로부터의 수소거동을 분석하기 위한 기초 실험(실험 A)과 안전주입 탱크 격실에서의 수소거동을 분석하기 위해 원형 혼합 chamber를 구상했다. 기초실험 A에서는 혼합 chamber내 축 방향으로 대칭적인 오리피스형 장애물을 설치하고 실험했고 안전주입 탱크 격실을 모사한 실험 B는 영광 3&4호기를 바탕으로 축소시켜 안전주입탱크 격실내 존재하는 두충과 안전 주입 탱크 사이의 틀을 통한 혼합체의 거동을 분석했다. 실험결과 오리피스형 장애물을 설치한 기초실험에서는 원형 띠모양의 장애물이 혼합체의 거동에 큰 영향을 주지 않는 것이 관측됐지만 안전주입탱크격실 실험에서는 격실내 장애물로 존재하는 두충이 혼합체의 거동에 큰 영향을 주는 것이 관측됐다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.4
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• pp.319-328
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• 2005

This paper describes a compartment dynamic model for evaluating the contamination level of kritium in agricultural plants exposed by accidentally released tritium. The present model uses a time-dependent growth equation of plant so that it can predict the effect of growth stage of plant during the exposure time. The model including atmosphere, soil and plant compartments is described by a set of nonlinear ordinary differential equations, and is able to predict time-dependent concentrations of tritium in the compartments. To validate the model, a series of exposure experiments of HTO vapor on Chinese cabbage and radish was carried out at the different growth stage of each plant. At the end of exposure, the tissue free water(TFWT) and the organically bound tritium(OBT) were measured. The measured concentrations were agreed well with model predictions.

• Journal of the Korea Society for Simulation
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• v.28 no.1
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• pp.109-115
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• 2019

The probability of lethality of personnel targets inside a room is a key issue at assessing effectiveness of a weapon system. In this study, the minimum charge weight to achieve 100% lethality of personnel targets inside a box-type room is proposed at each side length of a base of a room. A fast running blast wave model is used to simulate the pressure-time histories of the blast generated by an internal explosion inside a room, and Axelsson SP method is used to evaluate the lethality of personnel targets under the blast. 176 different internal explosion scenarios are simulated for cases of TNT weights ranging from 20kg to 170kg inside a room whose square base has a side length ranging from 5m to 15m. A linear model and a charge-density model were developed to predict the minimum charge weight to achieve 100% lethality inside a room given a length of a base of a room.

• Journal of Radiation Protection and Research
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• v.28 no.1
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• pp.43-50
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• 2003

This study describes a practical method for interpretation of bioassay results of inhaled uranium to assess the committed effective doses both for chronic and acute intake situations. Organs in the body were represented by a series of mathematical compartments for analysis of the behavior of uranium in the body according to the gastrointestinal track model, respiratory track model and biokinetic model recommended by the ICRP. An analytical solutions of the system of balance equations among the compartments were obtained using the Birchall's algorithm, and the urinary excretion function and the lung retention function of uranium were obtained. An initial or total intakes by intake modes were calculated by applying excretion and retention functions to the urinary uranium concentration and the lung burden measured with a lung counter. The dose coefficients given in ICRP 78 are used to estimate the committed effective doses from the calculated intakes.

• Journal of Radiation Protection and Research
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• v.19 no.1
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• pp.69-80
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• 1994

The TCMI(Three-Compartment Model for iodine) computer code has been developed, which is based on the three-compartment model and the respiratory model recommended in ICRP publication 54. This code is able to evaluate the thyroid burden, dose equivalent, committed dose equivalent and urinary excretion rate as time-dependent functions from the input data: working time and the radioiodine concentration in air. Using the TCMI code, the time-dependent thyroid burdens, the thyroid doses and the urinary excretion rates were calculated for three specific exposure patterns : acute, chronic and periodic. Applicability as an internal dose evaluation method has been assessed by comparing the results with some operational experiences. Simple equations and tables are provided to be used in the evaluation of the thyroid burden and the resulting doses for given I-131 concentration in air and the working time.

• Journal of Radiation Protection and Research
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• v.30 no.1
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• pp.45-54
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• 2005

A dynamic compartment model was developed to appraise the level of the contamination of agricultural plants by accidentally released tritium from nuclear facility. The model consists of a set of inter-connected compartments representing atmosphere, soil and plant. In the model three categories of plant are considered: leafy vegetables, grain plants and tuber plants, of which each is modeled separately to account for the different transport pathways of tritium. The predictive accuracy of the model was tested through the analysis of the tritium exposure experiments for rice-plants. The predicted TFWT(tissue free water tritium) concentration of the rice ear at harvest was greatly affected by the absolute humidity of air, the ratio of root uptake, and the rate of rainfall, while its OBT(organically bound tritium) concentration the stowing period of the ear, the absolute humidity of air and the content of hydrogen in the organic phase. There was a good agreement between the model prediction and the experimental results lot the OBT concentration of the ear.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.5
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• pp.553-562
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• 2012

Computational Fluid Dynamics (CFD) analysis has been performed to estimate the air temperature inside an Auxiliary Feed Water (AFW) Motor-Driven (MD) pump room for the case where there is loss of Heating, Ventilation, and Air-Conditioning (HVAC). A transient calculation for the closed pump room without cooling by any HVAC system shows that the volume-averaged air temperature reaches around $60^{\circ}C$ for a transient period of 8.0 h. From previous studies, the external air and surface boundary temperatures are assumed to increase slowly starting from an initial temperature of $35^{\circ}C$. For the cases where the door is opened at 2, 4, and 6 h after the initiation of HVAC failure, the average air temperature promptly drops by about $4^{\circ}C$ when the door is opened and then slowly increases. The current calculations based on the CFD technique predict the rate of increase of air temperature to be lower than that determined by previous conservative calculations on the basis of a lumped model.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.05a
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• pp.411.1-411
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• 2002

• Fire Science and Engineering
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• v.24 no.5
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• pp.60-67
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• 2010

Fire model shall be verified and validated to reliably predict the consequences of fires within its limitations. Generally the verification and validation procedures are conducted by comparison with experimental test data. This study aims to evaluate predictive capabilities of FDS in the pool fire with two rooms and the sensitivity between input parameters such as heat release rate and ventilation rate and the output values like temperature, concentration, and heat flux. The predictive capabilities of FDS will be evaluated by comparing FDS simulation results with PRISME experimental data which result from the international fire test project. The sensitivity analysis will be conducted to decide which one of input parameters affects outcomes by comparison of FDS results with ${\pm}$ 10% changes of input parameter. From this study, the FDS predictive capabilities are within 20% error range. Heat release rate as input parameter affects most of outcomes and flow rate only has relation with concentration of oxygen and combustion products.