제주 차귀도 연안해역 미생물 분포 및 이화학적 특성

문영건,김만철,이준백,송춘복,여인규,김종만,박근태,손홍주,최우봉,허문수 한국환경과학회 2006 한국환경과학회지 Vol.15 No.3

TOKAMAK REACTOR SYSTEM ANALYSIS CODE FOR THE CONCEPTUAL DEVELOPMENT OF DEMO REACTOR

Hong, Bong-Guen,Lee, Dong-Won,In, Sang-Ryul Korean Nuclear Society 2008 Nuclear Engineering and Technology Vol.40 No.1

Tokamak reactor system analysis code was developed at KAERI (Korea Atomic Energy Research Institute) and is used here for the conceptual development of a DEMO reactor. In the system analysis code, prospects of the development of plasma physics and the relevant technology are included in a simple mathematical model, i.e., the overall plant power balance equation and the plasma power balance equation. This system analysis code provides satisfactory results for developing the concept of a DEMO reactor and for identifying the necessary R&D areas, both in the physics and technology areas for the realization of the concept. With this system analysis code, the performance of a DEMO reactor with a limited extension of the plasma physics and technology adopted in the ITER design. The main requirements for the DEMO reactor were selected as: 1) demonstrate tritium self-sufficiency, 2) generate net electricity, and 3) achieve a steady-state operation. It was shown that to access an operational region for higher performance, the main restrictions are presented by the divertor heat load and the steady-state operation requirements.

Impact of inboard materials on the size of a tokamak fusion reactor

Bong Guen HONG 한국진공학회 2021 한국진공학회 학술발표회초록집 Vol.2021 No.2

Impact of inboard materials on the size of a tokamak fusion reactor were studied via a coupled analysis of tokamak systems and neutron transport. The shielding capability was the best for a tungsten carbide (WC), showing smaller reactor size than cases using other shield materials. It was found that the tritium self-sufficiency requirement could be satisfied with an inboard blanket replaced by neutron multiplier and/or reflector materials. An optimum combination of the multiplier and reflector materials can lead to smaller reactor size than the reactor with an inboard blanket.

TOKAMAK REACTOR SYSTEM ANALYSIS CODE FOR THE CONCEPTUAL DEVELOPMENT OF DEMO REACTOR

BONG GUEN HONG,DONG WON LEE,SANG RYUL IN 한국원자력학회 2008 Nuclear Engineering and Technology Vol.40 No.1

Tokamak reactor system analysis code was developed at KAERI (Korea Atomic Energy Research Institute) and is used here for the conceptual development of a DEMO reactor. In the system analysis code, prospects of the development of plasma physics and the relevant technology are included in a simple mathematical model, i.e., the overall plant power balance equation and the plasma power balance equation. This system analysis code provides satisfactory results for developing the concept of a DEMO reactor and for identifying the necessary R&D areas, both in the physics and technology areas for the realization of the concept. With this system analysis code, the performance of a DEMO reactor with a limited extension of the plasma physics and technology adopted in the ITER design. The main requirements for the DEMO reactor were selected as: 1) demonstrate tritium self-sufficiency, 2) generate net electricity, and 3) achieve a steady-state operation. It was shown that to access an operational region for higher performance, the main restrictions are presented by the divertor heat load and the steady-state operation requirements.

우주용 내열재료 삭마시험용 플라즈마 풍동의 운전 특성

홍봉근(Bong Guen Hong) 한국추진공학회 2014 한국추진공학회 학술대회논문집 Vol.2014 No.12

우주용 내열재료 삭마 시험을 위한 초음속 고엔탈피 플라즈마 풍동이 전북대학교 고온플라즈마응용 연구센터에 구축되었다. 구축이 완료된 플라즈마 풍동은 0.4㎿ 및 2.4㎿급 플라즈마 풍동이며 본 논문에서는 2가지 형태의 플라즈마 풍동의 운전 특성을 확인하였다. 0.4㎿급 플라즈마 풍동의 경우 공기 아르곤 혼합기체 16 g/s를 이용하여 13 MJ/㎏의 엔탈피를 갖는 유체를 마하3 속도로 안정적으로 가속시키는 것을 확인하였고 2.4㎿급 플라즈마 풍동의 경우 공기 아르곤 혼합기체 60 g/s를 이용하여 20 MJ/㎏의 엔탈피를 갖는 유체를 마하5의 속도로 가속 가능한 것이 확인되어 향후 우주용 내열재료 시험 및 열 방어 구조 설계를 위한 토대가 마련되었다. Supersonic high enthalpy plasma wind tunnel has been constructed at Chonbuk National University(CBNU). The facilities are 1 set of 2.4 ㎿ class wind tunnel and 1 set of 2.4 ㎿ calss wind tunnel. The segmented arc plasma torch was employed as a plasma source, and it can produce a supersonic high enthalpy flow with enthalpy above 13 MJ/㎏ at a velocity of Mach No. 3 and with enthalpy above 20 MJ/㎏ at a velocity of Mach No. 5.

Comparison of Optical and Scintillation Images Obtained by Using a Fiber-Optic Beta/Gamma Imaging Detector

Hong, Seung Han,Yoo, Wook Jae,Shin, Sang Hun,Sim, Hyeok In,Kim, Seon Guen,Jeon, Hye Su,Jang, Jae Seok,Kim, Jae Seok,Kwon, Gu Won,Jang, Kyoung Won,Lee, Bong Soo Trans Tech Publications, Ltd. 2015 Advanced materials research Vol.1083 No.-

<P>We developed a fiber-optic beta/gamma imaging detector that can obtain the scintillating images for beta-or gamma-ray emitted from the radioisotope. To evaluate spatial resolution of proposed imaging detector, we obtained the optical images using USAF 1951 resolution target. And then, a modulation transfer function curve of the optical image was calculated. Also, we measured the scintillating images of Tl-204 and Cs-137 with information respecting the beta-and gamma-rays distribution. Finally, the intensities of scintillating light as a function of radioactivity were analyzed from the region of interest in the scintillating image.</P>

Effect of tokamak neutron source shape on radwaste transmutation

Elsevier 2019 Fusion engineering and design Vol.147 No.-

<P><B>Abstract</B></P> <P>The effects of tokamak neutron source shape on the radial build and transmutation characteristics of a transmutation reactor were investigated. The optimal dimension of the reactor components was determined by the requirements not only on plasma physics and tokamak engineering, but also on neutronic performance. Tokamak neutron source shapes with two aspect ratios and two blanket configurations were compared. With the plasma physics and tokamak engineering constraints moderately extrapolated from the International Thermonuclear Experimental Reactor (ITER) design, the transmutation reactor with a normal aspect ratio (NAR) tokamak neutron source showed better transmutation performance with a smaller system dimension and larger fusion power than a low aspect ratio (LAR) tokamak neutron source. It was also shown that, with separate TRU burning and tritium breeding blanket configuration, the transmutation ratio was larger with the smaller initial TRU inventory than with merged TRU burning and tritium breeding blanket configuration.</P>

A study regarding the optimal radial build of a low-aspect-ratio tokamak fusion system

Elsevier 2018 Fusion engineering and design Vol.135 No.1

<P><B>Abstract</B></P> <P>System parameters and the optimal radial build of a low-aspect-ratio (LAR) tokamak fusion system were found through the coupled analysis of a tokamak system and neutron transport. In a configuration with only an outboard breeding blanket, the minimum major radius to produce a given fusion power was determined by the shielding requirements and the magnetic field at the toroidal field (TF) coil. With a confinement enhancement factor <I>H</I> = 1.4, <I>Q</I> > 10 was possible for fusion power greater than 800 MW with an aspect ratio of <I>A</I> = 1.5; however, <I>Q</I> > 10 was possible for fusion power greater than 1800 MW with an aspect ratio of <I>A</I> = 2.0. The outboard radial build was determined by the tritium breeding and shielding requirements. The tritium breeding capability of blanket concepts proposed for testing in the International Thermonuclear Experimental Reactor (ITER) was evaluated by varying the outboard blanket thickness and the degree of lithium-6 (Li-6) enrichment. Cases with a smaller aspect ratio exhibited better performance since the number of fusion neutrons that contributed to tritium breeding were larger than the case with a larger aspect ratio. Among the blanket concepts, a helium (He)-cooled solid breeder (HCSB) concept showed the best tritium breeding capability and thus allowed for a smaller system size.</P> <P><B>Highlights</B></P> <P> <UL> <LI> System parameters and the optimal radial build of a low-aspect-ratio tokamak fusion system were found. </LI> <LI> Cases with a smaller aspect ratio yielded better tritium breeding capability than for the case with a larger aspect ratio. </LI> <LI> The HCSB concept demonstrated the best tritium breeding capability and allowed smaller system size for the LAR tokamak fusion system. </LI> </UL> </P>

ADSL기술 표준화 동향 및 가입자망 구축방안

권근범(Guen-Bum Kwon),정부영(Boo-young Jung),최봉근(Bong-guen Choi),이상홍(Sang-hong Lee) 한국통신학회 1998 한국통신학회 학술대회논문집 Vol.1998 No.7

Bronchiolitis Obliterans Organizing Pneumonia 1 례

최봉근(Bong Kuen Choi),강태훈(Tae Hun Kang),배광열(Kwang Lyul Bae),황규근(Kyu Guen Hwang),최안홍(Ahn Hong Choi) 대한소아알레르기호흡기학회 1995 소아알레르기 및 호흡기학회지 Vol.5 No.2

Bronchiolitis obliterans organizing pneumonia (BOOP) is a type of diffuse interstitial lung disease that primarily affects the small conducting airways and presence of granulation tissue plug within the lumen of small airways that sometimes completely obstruct the airways and extend into alveolar ducts and alveoli with a variable degree of interstitial infiltration of mononuclear cells. BOOP may be seen with infections, drugs, connective tissue diseases, toxic-fume exposure, allergy and idiopathic, it is differentiated from bronchiolitis obliterans that is not associated with organizing pneumonia, We experienced a case of idiopathic BOOP. The patient was a 11 year old girl presented with 45 days history of exertional dyspnea and 21 days coughing. The physical examination showed chronic ill-appearance and rales on both lung. Chest X-ray and high resonance chest CT showed bilaterally diffuse ground glass opacities. Thoracoscopic lung biopsy carried out and showed characteristic findings of BOOP. After prednisolone therapy, dyspnea and coughing disappeared and chest X-ray finding was improved. We report a case of BOOP with brief review of related literatures.