탄소피막입자 핵연료를 이용한 가압경수로 노심 핵설계

김명현,배강목,이승기 경희대학교 산학협력기술연구원 1997 산학협력기술연구논문집 Vol.3 No.-

The use of carbon coated fuel particles was applied to the PWR fuel assembly design in order to enhance the safety The feasibility of assembly design was tested and optimum design parameters were sought for the fuel assemblies with particle fuels. Fuel temperature coefficient and moderator temperature coefficient were shown to be all negative, at the operating temperature range. The average fuel temperature at the full power condition was found to be reduced by 150℃ compared to the conventional PWR. A reactor core could be designed within acceptable limits when the core was loaded only with these fuel assemblies.

CORE DESIGN FOR HETEROGENEOUS THORIUM FUEL ASSEMBLIES FOR PWR (II) - THERMAL HYDRAULIC ANALYSIS AND SPENT FUEL CHARACTERISTICS

BAE KANG-MOK,HAN KYU-HYUN,KIM MYUNG-HYUN,CHANG SOON-HEUNG Korean Nuclear Society 2005 Nuclear Engineering and Technology Vol.37 No.4

A heterogeneous thorium-based Kyung Hee Thorium Fuel (KTF) assembly design was assessed for application in the APR-1400 to study the feasibility of using thorium fuel in a conventional pressurized water reactor (PWR). Thermal hydraulic safety was examined for the thorium-based APR-1400 core, focusing on the Departure from Nucleate Boiling Ratio (DNBR) and Large Break Loss of Coolant Accident (LBLOCA) analysis. To satisfy the minimum DNBR (MDNBR) safety limit condition, MDNBR>1.3, a new grid design was adopted, that enabled grids in the seed and blanket assemblies to have different loss coefficients to the coolant flow. The fuel radius of the blanket was enlarged to increase the mass flow rate in the seed channel. Under transient conditions, the MDNBR values for the Beginning of Cycle (BOC), Middle of Cycle (MOC), and End of Cycle (EOC) were 1.367, 1.465, and 1.554, respectively, despite the high power tilt across the seed and blanket. Anticipated transient for the DNBR analysis were simulated at conditions of $112\%$ over-power, $95\%$ flow rate, and $2^{\circ}C$ higher inlet temperature. The maximum peak cladding temperature (PCT) was 1,173K for the severe accident condition of the LBLOCA, while the limit condition was 1,477K. The proliferation resistance potential of the thorium-based core was found to be much higher than that of the conventional $UO_2$ fuel core, $25\%$ larger in Bare Critical Mass (BCM), $60\%$ larger in Spontaneous Neutron Source (SNS), and $155\%$ larger in Thermal Generation (TG) rate; however, the radio-toxicity of the spent fuel was higher than that of $UO_2$ fuel, making it more environmentally unfriendly due to its high burnup rate.

CORE DESIGN FOR HETEROGENEOUS THORIUM FUEL ASSEMBLIES FOR PWR(1)-NUCLEAR DESIGN AND FUEL CYCLE ECONOMY

BAE KANG-MOK,KIM MYUNG-HYUN Korean Nuclear Society 2005 Nuclear Engineering and Technology Vol.37 No.1

Kyung-hee Thorium Fuel (KTF), a heterogeneous thorium-based seed and blanket design concept for pressurized light water reactors, is being studied as an alternative to enhance proliferation resistance and fuel cycle economics of PWRs. The proliferation resistance characteristics of the KTF assembly design were evaluated through parametric studies using neutronic performance indices such as Bare Critical Mass (BCM), Spontaneous Neutron Source rate (SNS), Thermal Generation rate (TG), and Radio-Toxicity. Also, Fissile Economic Index (FEI), a new index for gauging fuel cycle economy, was suggested and applied to optimize the KTF design. A core loaded with optimized KTF assemblies with a seed-to-blanket ratio of 1: 1 was tested at the Korea Next Generation Reactor (KNGR), ARP-1400. Core design characteristics for cycle length, power distribution, and power peaking were evaluated by HELIOS and MASTER code systems for nine reload cycles. The core calculation results show that the KTF assembly design has nearly the same neutronic performance as those of a conventional $UO_2$ fuel assembly. However, the power peaking factor is relatively higher than that of conventional PWRs as the maximum Fq is 2.69 at the M$9^{th}$ equilibrium cycle while the design limit is 2.58. In order to assess the economic potential of a heterogeneous thorium fuel core, the front-end fuel cycle costs as well as the spent fuel disposal costs were compared with those of a reference PWR fueled with $UO_2$. In the case of comprising back-end fuel cycle cost, the fuel cycle cost of APR-1400 with a KTF assembly is 4.99 mills/KWe-yr, which is lower than that (5.23 mills/KWe-yr) of a conventional PWR. Proliferation resistance potential, BCM, SNS, and TG of a heterogeneous thorium-fueled core are much higher than those of the $UO_2$ core. The once-through fuel cycle application of heterogeneous thorium fuel assemblies demonstrated good competitiveness relative to $UO_2$ in terms of economics.

Core Design for Heterogeneous Thorium Fuel Assemblies for PWR (I) - Nuclear Design and Fuel Cycle Economy

KANG-MOK BAE,MYUNG-HYUN KIM 한국원자력학회 2005 Nuclear Engineering and Technology Vol.37 No.1

CORE DESIGN FOR HETEROGENEOUS THORIUM FUELASSEMBLIES FOR PWR (II) - THERMAL HYDRAULICANALYSIS AND SPENT FUEL CHARACTERISTICS

KANG-MOK BAE,김명현,KYU-HYUN HAN,SOON-HEUNG CHANG 한국원자력학회 2005 Nuclear Engineering and Technology Vol.37 No.4

A heterogeneous thorium-based Kyung Hee Thorium Fuel (KTF) assembly design was assessed for application in the APR-1400 to study the feasibility of using thorium fuel in a conventional pressurized water reactor (PWR). Thermal hydraulic safety was examined for the thorium-based APR-1400 core, focusing on the Departure from Nucleate Boiling Ratio (DNBR) and Large Break Loss of Coolant Accident (LBLOCA) analysis. To satisfy the minimum DNBR (MDNBR) safety limit condition, MDNBR>1.3, a new grid design was adopted, that enabled grids in the seed and blanket assemblies to have different loss coefficients to the coolant flow. The fuel radius of the blanket was enlarged to increase the mass flow rate in the seed channel. Under transient conditions, the MDNBR values for the Beginning of Cycle (BOC), Middle of Cycle (MOC), and End of Cycle (EOC) were 1.367, 1.465, and 1.554, respectively, despite the high power tilt across the seed and blanket. Anticipated transient for the DNBR analysis were simulated at conditions of 112% over-power, 95% flow rate, and 2 C higher inlet temperature. The maximum peak cladding temperature (PCT) was 1,173K for the severe accident condition of the LBLOCA, while the limit condition was 1,477K. The proliferation resistance potential of the thorium-based core was found to be much higher than that of the conventional UO2 fuel core, 25% larger in Bare Critical Mass (BCM), 60% larger in Spontaneous Neutron Source (SNS), and 155% larger in Thermal Generation (TG) rate; however, the radio-toxicity of the spent fuel was higher than that of UO2 fuel, making it more environmentally unfriendly due to its high burnup rate.

RESEARCH ACTIVITIES ON A SUPERCRITICAL PRESSURE WATER REACTOR IN KOREA

Bae, Yoon-Yeong,Jang, Jin-Sung,Kim, Hwan-Yeol,Yoon, Han-Young,Kang, Han-Ok,Bae, Kang-Mok Korean Nuclear Society 2007 Nuclear Engineering and Technology Vol.39 No.4

This paper presents the research activities performed to date for the development of a supercritical pressure water-cooled reactor (SCWR) in Korea. The research areas include a conceptual design of an SCWR with an internal flow recirculation, a reactor core conceptual design, a heat transfer test with supercritical $CO_2$, an adaptation of an existing safety analysis code to the supercritical pressure condition, and an evaluation of candidate materials through a corrosion study. Methods to reduce the cladding temperature are introduced from two different perspectives, namely, thermal-hydraulics and core neutronics. Briefly described are the results of an experiment on the heat transfer at a supercritical pressure, an experiment that is essential for the analysis of the subchannels of fuel assemblies and the analysis of a system safety. An existing system code has been adapted to SCWR conditions, and the process of a first-hand validation is presented. Finally, the corrosion test results of the candidate materials for an SCWR are introduced.

Gravitational radiation driven capture in unequal mass black hole encounters

Bae, Yeong-Bok,Lee, Hyung Mok,Kang, Gungwon,Hansen, Jakob American Physical Society 2017 Physical Review D Vol.96 No.8

<P>The gravitational radiation driven capture (GR capture) between unequal mass black holes without spins has been investigated with numerical relativistic simulations. We adopt the parabolic approximation which assumes that the gravitational wave radiation from a weakly hyperbolic orbit is the same as that from the parabolic orbit having the same pericenter distance. Using the radiated energies from the parabolic orbit simulations, we have obtained the critical impact parameter (b(crit)) for the GR capture for weakly hyperbolic orbit as a function of initial energy. The most energetic encounters occur around the boundary between the direct merging and the fly-by orbits, and can emit several percent of total initial energy at the peak. When the total mass is fixed, energy and angular momentum radiated in the case of unequal mass black holes are smaller than those of equal mass black holes having the same initial orbital angular momentum for the fly-by orbits. We have compared our results with two different post-Newtonian (PN) approximations, the exact parabolic orbit (EPO) and PN corrected orbit (PNCO). We find that the agreement between the EPO and the numerical relativity breaks down for very close encounters (e.g., b(crit) less than or similar to 100 M), and it becomes worse for higher mass ratios. For instance, the critical impact parameters can differ by more than 50% from those obtained in EPO if the relative velocity at infinity v(infinity) is larger than 0.1 for the mass ratio of m(1)/m(2) = 16. The PNCO gives more consistent results than EPO, but it also underestimates the critical impact parameter for the GR capture at b(crit) less than or similar to 40 M.</P>

開業專門醫의 專門科目以外의 診療에 對한 實態調査

姜星圭,朴鍾文,金永會,李仁培,睦遇均 全北大學校 學徒護國團 1981 全國大學生學術硏究發表論文集 Vol.6 No.-

A survey was got from analysing the actualities of the treatment of the other special department by practising specialists, from 1 May to 31 July 1981. The subjects were chosen randomly, 887 practising specialists, registrated in Korean Medical Association. The following results were obtained: 1. Out of the respondents, comparative percentage of the specialists who treated patient of the other special department seemed 49.5%. This rate was higher in the province than in the urban region. 2. In the treatment of the otehr special department, 53.9% of the respondents treated only related departments. We can see the more departments were treated in the provincial region. 3. General surgeons practised at the higher rate of local clinical opening on the province (44.4%) in comparison with the urban region and the most of the other specialists were in practise in the urban region. 4. In the local clinics of general surgery, the treatment of the other special department were served at the rate of 51.0% and the kind of the dealing departments was relatively variable. 5. Major reasons of the treatment of the other special department were the request of patients and their guardians(36.5%) and reagional conditions(18.4%). 6. In the attitude to the treatment of the patient of other special department, comparative percentage of the responses that specialists could treat any patients case by case was 63.2%. 7. 49.3% of the respondents was against the fact that the treatment of the other special department could give the good medical service. There were the positive responses in the province in contrast to the urban region. 8. In order to enrich the treatment of special department, the following needs to be done; A establishment of the medical delivery system(44.2%), a raise of the charge of the medical treatment(26.0%).

농촌지역에서 신체장애인의 유병률 조사

김현배,박시복,이상건,이강목,신영전,최보율 大韓再活醫學會 1998 Annals of Rehabilitation Medicine Vol.22 No.1

바이모달 트램의 직렬형 하이브리드 추진계 성능검토

배창한(Bae Chang-han),장세기(Chang Seky),목재균(Mok Jai-kyun),이강원(Lee Kang-won),변윤섭(Byun Yeun-sub) 한국철도학회 2008 한국철도학회 학술발표대회논문집 Vol.- No.-

A bimodal low-floor tram is designed to provide the flexibility of bus and the punctuality of trains together to the passengers. Its propulsion system is a series hybrid type using a set of CNG engine generator and Li-polymer battery. The present paper describes the specifications of the propulsion system in the bimodal tram which was drawn by a desirable driving cycle. In addition, it shows how the propulsion system of the bimodal tram can be controlled. With using a computer simulation tool of hybrid vehicles, ADVISOR, the performance of the bimodal tram was verified.