피동형 원자로의 Hydraulic Valve 특성 실험

김상녕,김융석,Kim, Sang-Nyung,Kim, Yoong-Seock 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.8

A kind of three-way check valve, so called hydraulic calve was proposed for the substitute of the density lock of passive reactor such as SPWR (System-Integrated Pressurized Water Reactor). The function of the valve are the separation of the borated water from main coolant loop for normal operation and the insurge of the water into the loop for shutdown and the removal of the decay power when the main coolant flow rate is not enough. To verify the operability and the characteristics of the valve, experimental works were executed with 1/3 scale model calve. Also a diffuser model was proposed for the theoretical analysis of the valve.

증기발생기 급수입구 수평배관의 열성층 실험 연구

김철홍(Cheol-Hong Kim),김상녕(Sang-Nyung Kim),윤범수(Bum-Su Youn) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

원자력발전소의 부품들은 수명 기간동안 열성층 등과 같은 열수력 현상에 의하여 배관 파손 및 이탈, 열적 피로, 휘어짐 그리고 지지대 파손 등을 경험하고 있다. 특히 증기발생기 급수 입구부 수평배관에서는 부품의 운전 특성상 빈번하게 열성층이 발생한다. 이로 인해 1970년대 말을 전후 하여 미국을 비롯한 세계 각국의 PWR 발전소에서 배관의 균열과 누설을 다수 경험하였다. 이는 과도 시(보조급수 작동 시) 증기발생기 급수 입구 수평배관에서 열성층으로 인한 열응력이 설계단계에서 반영되지 못했기 때문이다. 따라서 본 연구는 국내 원전을 KSNP와 구형 발전소(고리 1,2,3,4호기, 영광 1,2호기 및 울진 1,2호기)로 구분하여 증기발생기 급수 입구부 수평배관에서 보조급수 유입량과 증기발생기로부터 역류되는 고온수량에 따른 열성층과 열주기 발생 가능성에 대한 실증 설험을 수행하였다. 그 결과 KSNP에서는 열성층 발생 가능성이 희박한 반면, 구형 발전소 증기발생기 급수 입구 수평배관에서는 열성층 현상이 발생하는 것으로 판명되어 이에 대한 개선 필요성이 제기되었다.

다발형 써모사이폰의 열전달 성능에 관한 실험적 연구

남경호(Gyeong-Ho Nam),김상녕(Sang-Nyung Kim) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

Multi-Pod Heat Pipe(MPHP) is a new concept of assembly type of Two-Phase Closed Thermosyphon(TPCT) that was designed to be applied to the Passive Containment Cooling System(PCCS) of the nuclear power plant, using the characteristic of TPCT’s heat transfer according to the phase change of the working fluid. Main purpose of this study is to verify the function of the MPHP designed to remove decay heat that occurs in the containment, in the event of severe accidents, by crafting miniatures and through it, to verify the maximum heat value that the assembly type TPCT is able to cool down. The experiment was conducted in the ranges of 6~9kW, based on the theoretical results, and as a result, the maximum internal temperature increased by 2℃with each increase of 1kW, and the temperature of the steady state was maintained at the 112℃~114℃. Due to the fact that the heat transfer was more actively than expected, the internal pressure of the Boiling tank decreased before reaching the accident conditions, it was confirmed that more than 100% of the heat transfer took place rather than theoretically calculated expectation of 7kW of heat removal.

IRWST 수조 내의 온도분포 실험

윤기훈(Ki-Hoon Yoon),김상녕(Sang-Nyung Kim),정현철(Hyun-cheol Jeong) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

The In-Containment Refueling Water Storage Tank (IRWST), one of the design improvements applied to the APR-1400, has a function to condense the high enthalpy fluid discharged from the Reactor Coolant System (RCS). The condensation of discharged fluid by the tank water drives the tank temperature high and causes oscillatory condensation. Also if the tank cooling water temperature approaches the saturated state, the steam bubble may escape from the water uncondensed. These oscillatory condensation and bubble escape would burden the undue load to the tank structure, pressurize the tank, and degrade its intended function. For these reasons, experimental works (1:400 volume scaled) on the temperature distribution and steam condensation characteristic in IRWST has performed. As a result of the experiments, a temperature of water surface was highest and a temperature of lower part of the tank stagnated.

구조 정보의 통합관리를 위한 SGML 엔티티 관리자의 구현

김현기(Hyun-Ki Kim),김상녕(Sang-Nyung Kim),주종철(Zong-Cheol Zhoo) 한국정보과학회 1997 한국정보과학회 학술발표논문집 Vol.24 No.1B

SGML 데이타를 응용 프로그램에 독립적으로 사용하기 위해서는 SGML 문서의 논리적 저장 객체인 엔티티에 대한 관리가 필요하다. 이때, SGML 데이타의 통합 관리를 위해서는 로컬 시스템에서 SGML 문서가 응용 프로그램들에 독립적으로 사용될 수 있는 외부 식별자 해석과 다른 시스템으로 SGML 문서가 전달될 때 외부 식별자에 지정된 저장 객체들의 의미 보존문제 문제를 해결해야 한다. 본 논문에서는 이러한 문제들을 해결하고SGML 데이타의 통합 관리를 위해 엔티티 관리자를 구현한다. 구현한 엔티티 관리자를 사용하여 얻을 수 있는 장점들은 다음과 같다. 첫째, 사용자가 SGML 응용 프로그램에 독립적으로 엔티티 구조를 사용할 수 있다. 둘째, 파일 시스템, URL 관리기 등의 다수 저장 시스템을 지원함으로써 엔티티를 다수의 저장 객체로 분할하는 기능, 다수의 저장 객체로 분할된 엔티티를 하나의 저장 객체로 저장하는 기능들을 제공한다.

회수 가능 CANDU 사용후핵연료 처분터널에 대한 열 해석

차정훈,이종열,최희주,조동건,김상녕,윤범수,지준석,Cha, Jeong-Hun,Lee, Jong-Youl,Choi, Heui-Joo,Cho, Dong-Keun,Kim, Sang-Nyung,Youn, Bum-Soo,Ji, Joon-Suk 한국방사성폐기물학회 2008 방사성폐기물학회지 Vol.6 No.2

Thermal assessment of a new CANDU spent fuel disposal system, which improves the retrievability of the spent fuel and enhances the densification factor compared with the Korean Reference disposal System, is carried out in this study. The canisters for CANDU spent fuels are stored for long term and cooled by natural convection in the proposed disposal system for the retrievability. The steady state thermal analyses for proposed CANDU disposal system are carried out with the ANSYS 10.0 CFX code. The thermal analyses are performed through two steps. At the first step, the sensitivity of the disposal tunnel spacing is analysed. The differences of maximum temperatures by several tunnel spacings are calculated at three points in the disposal tunnel. The result shows that the differences of the temperature at the three points are almost negligible because 99% of the decay heat is removed by natural convection. At the second procedure, 60m tunnel spacing with a ventilation system instead of natural convection is considered. The result is applied to the calculation of the canister surface temperature in disposal tunnel as boundary conditions. Consequently, the average and the maximum surface temperature of disposal canisters are $79.9^{\circ}C$ and $119^{\circ}C$, respectively. The inner maximum temperature of a basket in the disposal canister is calculated as $140.9^{\circ}C$. The maximum temperature of the basket meets the thermal requirement for the CANDU spent fuel cladding.

급수가열기 동체 감육 현상 규명을 위한 유동해석 연구

김경훈 ( Kyung Hoon Kim ),황경모 ( Kyeong Mo Hwang ),김상녕 ( Sang Nyung Kim ) 한국분무공학회 2004 한국액체미립화학회지 Vol.9 No.4

N/A Feedwater flowing tube side of number 5 high pressure feedwater heaters was heated by extracting steam from high pressure turbine and draining water from moisture separators and number 6 high pressure feedwater heaters and supplied into steam generators. Because the extracting steam from the high pressure turbine is two phase fluid of high temperature. high pressure, and high speed and flows to inverse direction after impinging to impingement baffle, the shell wall of the number 5 high pressure feedwater heater may be affected by flow accelerated corrosion. On May 14, 1999. Point Beach Nuclear Plant (PBNP) with operating at full power experienced a steam leak from rupture of shell side of number 4B feedwater heater. Also, a domestic nuclear power plant experienced a severe wall thinning of shell side of number 5A and 5B feedwater heaters. This paper describes the fluid mixing analysis study using PHOENICS code in order to get at the root of the shell wall thinning of the feedwater heaters. The sections included in the fluid mixing analysis model are around the number 5A feedwater heater shell including the extracting pipeline. To identify the relation between the local velocities and wall thinning. the local velocities according to the analysis results were compared with the distribution of the shell wall thickness by ultrasonic test.

SGML 문서의 구조 편집을 위한 마크업 함수의 구현

노대식(Dae-Sik Roh),김상녕(Sang-Nyung Kim),이상기(Sang-Ki Lee) 한국정보과학회 1997 한국정보과학회 학술발표논문집 Vol.24 No.1B

SGML문서편집기는 일반 문서편집기의 기능에 부가하여 SGML 문서의 논리 구조를 사용자가 쉽게 변경할 수 있는 기능을 제공하여야 한다. 이와 같이 문서의 논리 구조를 변경하는 작업을 마크업(Markup)이라 한다. 이러한 마크업 기능을 제공하는데 있어서 시스템이 현재의 편집 위치에서 실행 가능한 마크업 편집 기능을 사용자에게 실시간에 메뉴 레벨로 제공한다면 마크업 편집이 용이하게 될 것이다. 따라서 본 논문에서는 이와 같은 마크업 기능을 사용자가 편기하게 사용할 수 있게 하는 방법과 이와 같은 기능을 제공하기 위해서 본 연구실에서 개발 중인 SGML 편집기인 KLE-OX 편집기 내부에서의 마크업 함수의 구현 방법을 설명하도록 한다.

다공판 유로 내의 유동한계(CCFL)에 대한 실험적 연구

양승우(Seung-Woo Yang),이진기(Jin-Ki Lee),권정태(Jeong-Tae Kwon),김상녕(Sang Nyung Kim),강용태(Yong Tae Kang) 대한설비공학회 2007 설비공학 논문집 Vol.19 No.2

??A set of experiments of counter-current flow limit (CCFL) was performed to improve the drawbacks of Wallis I correlation which neglected the effects of channel size, channel length, injection method and the boundary conditions at the inlet of liquid and gas phase. In this study, CCFL was observed by changing the shape of porous plate using air and water. The results show that as the size of porous increases, CCFL with a round shape of the porous plate start to disappear. In this study, the CCFL correlation was calculated and the corresponding CCFL map was developed based on the experimental results.

다발형 써모사이폰을 적용한 APR1400 격납건물 피동냉각계통 개념설계

남경호(Gyeong-Ho Nam),박준석(Jun-Seok Park),김상녕(Sang-Nyung Kim) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

As we can see in the case of the Fukushima nuclear power plant accident, the integrity of containment is directly related to the safety of a nuclear power plant. Because of this, various concepts, such as the Passive Containment Cooling System(PCCS), are in the process of research to ensure the integrity of the containment. In this study, the PCCS was designed in the form of a assembly where several Two-Phase Closed Thermosyphons(TPCT) comes together to form one adiabatic region by grafting TPCT, to minimize the number of penetrations on the top of the dome of the containment as well as to remove the decay heat. The main purpose of this study is to analyze the expected heat transfer phenomena and to confirm the interpretation of the resulting heat transfer coefficient when applying the TPCT assembly of Multi-Pod Heat Pipe(MPHP) to the APR1400.