• Nuclear Engineering and Technology
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• v.15 no.4
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• pp.248-255
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• 1983

The thermal analysis on the spent fuel shipping cask for a PWR fuel assembly is performed. Under the normal and fire-accident conditions the temperature distribution through a multilayer cask calculated in compliance with 10 CFR Part 71. A KNU 5&6 spent fuel assembly is assumed to be the decay heat source, which has the maximum discharge turnup of 45, 000MWD/MTU and has been stored in the spent fuel storage pool for 300 days. As a result of thermal analysis, the maximum cladding temperature in case of dry cavity under fire-accident conditions is calculated to be 455$^{\circ}C$. This value is much less than the limiting value specified in 10 CFR Part 50.46. It indicates that no fuel rod cladding rupture could occur under fire-accident conditions. It was also found that no melting of lead would take place in the major shield region.

• Physical Therapy Rehabilitation Science
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• v.9 no.2
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• pp.82-89
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• 2020

Objective: The purpose of this study was to assess the effect of hospital-based pulmonary rehabilitation (PR) on exercise capacity and quality of life as well as barriers to participation in persons with chronic obstructive pulmonary disease (COPD) in South Korea. Design: One-group pretest-posttest design. Methods: A total of 14 patients were enrolled in this study in an 8-week PR program with two 60-minute sessions per week. The program included: flexibility exercises, breathing techniques, strengthening exercises, and aerobic exercises. The outcomes were defined as changes in the variables before and after the PR program. A change in the 6-minute walk distance (6MWD) was defined as the primary outcome, and changes in pulmonary function test, respiratory and grip strength, and the St. George's Respiratory Questionnaire (SGRQ) about quality-of-life results were secondary outcomes. A dropout was defined as missing >3 of the 16 sessions. Results: Patients who completed the program showed a significant improvement of 43.57±39.43 m in the 6MWD (p<0.05), but no significant differences were noted for the other function tests. The SGRQ showed a significant improvement in the activity and total score (p<0.05). The total dropout rate was 53.3%. Newly developed symptoms, exacerbation of COPD, transport problems, and lack of motivation were major barriers to PR. Conclusions: Our study showed that an 8-week hospital-based PR program improved exercise capacity and quality of life but had a high dropout rate in individuals with COPD. Since comprehensive PR has only recently been established in South Korea, patient motivation and education are critical.

• Journal of the Korean Society of Safety
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• v.27 no.6
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• pp.78-83
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• 2012

In this study, some experimental results of the peroxide-degradation process of polypropylene(PP) in a co-rotating twin-screw extruder to produce controlled rheology polypropylene(CRPP) are presented. The peroxide was dicumyl peroxide(DCP) and the concentration of DCP was in the range 0-0.3 wt%. It was found that the rheological properties of PP change significantly during reactive extrusion. Melt flow index(MFI) increased with DCP concentration. Intrinsic viscosity decreases with increasing DCP concentration. From dynamic rheological data, number average molecular weight(Mn), weight average molecular weight(Mn) and molecular weight distribution(MWD) were calculated. Results indicated that Mw decreases and MWD becomes narrower with increasing peroxide concentration. Especially, particle size distribution of CRPP decreases with increasing DCP concentration by chemical powdering process, and anti-slip floor paint, CRPP(DCP 0.2 wt%) powder by 10phr was friction coefficient 2.15 ${\mu}$, abrasion resistance 511.18%.

• Nuclear Engineering and Technology
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• v.13 no.1
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• pp.1-11
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• 1981

The KINS (KAERI-Improved Nodal Simulation) program, a three-dimensional nodal simulation code for pressurized water reactors, has been developed and benchmarked against the first cycle of the Kori-1 reactor. The KINS program is based on the computational model used in FLARE code and has been modified to represent the PWR characteristics more explicitly. The critical boron concentration and three-dimensional power distribution at the beginning of life hot zero power have been calculated and compared with the operating data. A three-dimensional depletion calculation at the intervals of 1000 MWD/MTU turnup steps has been performed. As the result of comparison, our calculation is shown to be in excellent agreement with the operating data. It is displayed that, incorporated with the computing time, the KINS program is an effective and powerful tool for PWR core management.

• The Journal of Korean Medicine
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• v.43 no.1
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• pp.171-179
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• 2022

Objectives: The purpose of study was to report the clinical improvement of late complications of COVID-19 patient complaining of dyspnea treated with Korean medicine pulmonary rehabilitation. Methods: To assess the treatment outcomes, we used the modified medical research council scale (mMRC), 6-minute walk distance (6MWD), peak expiratory flow rate (PEFR), St. George respiratory questionnaire (SGRQ). Results: After treatments, the patient's clinical symptoms were improved with mMRC, 6MWD, PEFR, and SGRQ. Conclusions: The Korean medicine pulmonary rehabilitation was effective in the treatment of late complications of COVID-19 patient. This study suggested the possibility of Korean Medicine pulmonary rehabilitation program in the clinic for late complications of COVID-19.

• Nuclear Engineering and Technology
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• v.25 no.2
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• pp.248-254
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• 1993

The purpose of this study is to evaluate the thermal safety for dry transport of a shipping cask. Analysis condition was based on an ambient temperature of 38$^{\circ}C$ for normal heat condition. The cask was designed to carry 4PWR spent fuel assemblies with a burnup of 38,000 MWD/MTU and 3 years of cooling time. Thermal analysis was carried out by using the COBRA-SFS code. The fuel cavity was considered to be filled with air, nitrogen or helium gas for dry transport. The results of analysis showed that the maximum temperatures of fuel rod cladding in air and helium cavity would be 277$^{\circ}C$ and 226$^{\circ}C$, respectively, for 3 years of cooling time. These values were less than the specified temperature to maintain the thermal integrity of fuel assembly for dry transport.

• Nuclear Engineering and Technology
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• v.41 no.2
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• pp.179-186
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• 2009

This paper presents a thermal creep test under internal pressure and post-test characterization performed on high burnup (68 MWd/kgU) ZIRLO. This research has been done by the CSN, ENRESA, and ENUSA in order to investigate the behavior of advanced cladding materials in contemporary PWRs at higher burnup under dry cask storage conditions. Also, to investigate the hydride reorientation, the cool-down of the samples after the test has been done in a coordinated manner with the internal pressure. The creep results obtained are consistent with the expected behavior from reference CWSR material, Zr-4. During the test, the material retained significant ductility: one specimen leaked during the test at an engineering strain of the tube section of 17%; remarkably, the crack closed due to de-pressurization. Although significant hydride reorientation occurred during the cool-down under pressure, no specimen failed during the cool-down.

• Journal of Environmental Science International
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• v.7 no.1
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• pp.104-111
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• 1998

The Dongbok lake water before and after alum coagulation and activated carbon adsorption were analyzed in terms of organic contents, molecular weight distributuin (MWD), and UV-absorbance. Dissolved organic compounds in the Dongbok lake were fractionated into three molecular size classes by gel permeation chromatography. The fractionation was reasonably successful in isolating compounds with The bulk of the dissolved carbon was present in compounds of molecular weight in the range of 3,000~10,000. Alum coagulation preferentially treated molecules of high molecular weight, which has molecules larger than 10,000. The dissolved organic carbon (DOC) removal after activated carbon adsorption was high in the Fraction B , IR . The $A_{260}$/DOC ratio after alum and activated carbon treatment the Fraction II, III. This results suggest that the organics remaining after each treatment has a trihalomethane formation potential

• Journal of Powder Materials
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• v.6 no.3
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• pp.209-214
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• 1999

The oxidation behavior of the simulated spent fuel of burn up 33 MWD/kgU was investigated to predict that of the spent fuel in the temperature ranges of 400 to $700^{\circ}C$ and was compared with those of $UO_2$. The forms of uranium oxides after the oxidation were conformed by XRD analyses. The oxidation rate at each the temperature and the activation energy were obtained. After complete oxidation, the simulated spent fuel was converted to $U_3O_8$ and pulverized to powder due to the density difference between the simulated spent fuel and uranium oxides. The activation energies were 85.35 and 30.77kJ/mol in the temperature ranges of 400$\leq$T($^{\circ}C$)$\leq$500 and 500$\leq$T($^{\circ}C$)$\leq$700, respectively.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.11a
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• pp.311-312
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• 2009

가압 경수로에서 53,000 MWd/tU으로 연소된 사용후 핵연료의 PCI 영역에 대해 방사선 차폐형 성분 분석기기( Shielded EPMA)를 사용하여 반경방향에 대한 성분분포를 분석하였다. PCI 영역에서 산화층의 두께는 13um 이었으며, 핵분열생성물의 침투 두께는 시료에서 약 10 um 이내로 나타났다. 이 두께에 침투된 핵종의 총 농도는 1~2 wt%로 관찰되었다. 주요핵종은 Cs 0.5~0.7 wt%, Mo 0.2~0.3 wt%, Pd, Ru, Nd, Ce등이 0.1~0.2 wt% 로 관찰되었다.