항이뇨호르몬 부적절분비증을 동반한 결핵성 기흉

강영희,김경수,강창일,정정명,최하진 인제대학교 1983 仁濟醫學 Vol.4 No.3

A case of pulmonary tuberculosis associated with syndrome of inappropriate secretion of antidiuretic hormone in 39-year-old female is presented. Although proper treatment including the closed thoracotomy for her pneumthorax was preformed, generalized convulsion, mental deterioration and polyuria occurred. On laboratory examination, the hyponatremia in her serum and increased urinary excretion of sodium were noticed, accordingly the osmolality of urine was higher than that of plasmas. The syndrome of inappropriate secretion of antidiuretic hormone was diagnosed and treated with intravenovous hypertonic saline and water restriction for 35 days c satisfactory improvment.

Local Burnup Characteristics of PWR Spent Nuclear Fuels Discharged from Yeonggwang-2 Nuclear Power Plant

YEONG-KEONG HA,김정석,YOUNG SHIN JEON,한선호,HANG SEOK SEO,송규석 한국원자력학회 2010 Nuclear Engineering and Technology Vol.42 No.1

Spent UO2 nuclear fuel discharged from a nuclear power plant (NPP) contains fission products, U, Pu, and other actinides. Due to neutron capture by 238U in the rim region and a temperature gradient between the center and the rim of a fuel pellet, a considerable increase in the concentration of fission products, Pu, and other actinides are expected in the pellet periphery of high burnup fuel. The characterization of the radial profiles of the various isotopic concentrations is our main concern. For an analysis, spent nuclear fuels originating from the Yeonggwang-2 pressurized water reactor (PWR) were chosen as the test specimens. In this work, the distributions of some actinide isotopes were measured from center to rim of the spent fuel specimens by a radiation shielded laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS)system. Sampling was performed along the diameter of the specimen by reducing the sampling intervals from 500 μm in the center to 100 μm in the pellet periphery region. It was observed that the isotopic concentration ratios for minor actinides in the center of the specimen remain almost constant and increase near the pellet periphery due to the rim effect apart from the 236U to 235U ratio, which remains approximately constant. In addition, the distributions of local burnup were derived from the measured isotope ratios by applying the relationship between burnup and isotopic ratio for plutonium and minor actinides calculated by the ORIGEN2 code.

BEHAVIORS OF MOLYBDENUM IN UO2 FUEL MATRIX

YEONG-KEONG HA,JONG-GOO KIM,YANG SOON PARK,SOON DAL PARK,KYUSEOK SONG 한국원자력학회 2011 Nuclear Engineering and Technology Vol.43 No.3

Molybdenum is the most abundant fission product since its fission yield is equivalent to that of xenon, and it has a very special role in the chemistry of nuclear fuel because it influences the oxygen potential of UO2 fuel. In this study, the distribution of molybdenum in spent UO2 fuel specimens with 33.3, 41.0 and 57.6 GWd/tU burnup was measured by a LA-ICP-MS system and the reproducibility of the measured data was obtained. The Mo distribution was almost constant along the radius of a fuel except an increase at the periphery of the fuel. It showed a drop in reproducibility with relatively high deviation of measured values for the highest burnup fuel. To explain this, the state of molybdenum in a UO2 matrix and its effect on the oxidation behavior of UO2 were investigated. The low reproducibility was explained by the segregation of molybdenum, and the inhibition of oxidation by the molybdenum was also observed.

SHIELDED LASER ABLATION ICP-MS SYSTEM FOR THE CHARACTERIZATION OF HIGH BURNUP FUEL

Ha, Yeong-Keong,Han, Sun-Ho,Kim, Hyun-Gyum,Kim, Won-Ho,Jee, Kwang-Yong Korean Nuclear Society 2008 Nuclear Engineering and Technology Vol.40 No.4

In modem power reactors, nuclear fuels have recently reached 55,000 MWd/MtU from the initial average burnup of 35,000 MWd/MtU to reduce the fuel cycle cost and waste volume. At such high burnups, a fuel pellet produces fission products proportional to the burnup and creates a typical high burnup structure around the periphery region of the pellet, producing the so called 'rim effect'. This rim region of a highly burnt fuel is known to be ca. $200\;{\mu}m$ in width and is known to affect the fuel integrity. To characterize the local burnup in the rim region, solid sampling in the micro meter region by laser ablation is needed so that the distribution of isotopes can be determined by ICP-MS. For this procedure, special radiation shielding is required for personnel safety. In this study, we installed a radiation shielded laser ablation ICP-MS system, and a performance test of the developed system was conducted to evaluate the safe operation of instruments.

BEHAVIORS OF MOLYBDENUM IN UO₂ FUEL MATRIX

Ha, Yeong-Keong,Kim, Jong-Goo,Park, Yang-Soon,Park, Soon-Dal,Song, Kyu-Seok Korean Nuclear Society 2011 Nuclear Engineering and Technology Vol.43 No.3

Molybdenum is the most abundant fission product since its fission yield is equivalent to that of xenon, and it has a very special role in the chemistry of nuclear fuel because it influences the oxygen potential of $UO_2$ fuel. In this study, the distribution of molybdenum in spent $UO_2$ fuel specimens with 33.3, 41.0 and 57.6 GWd/tU burnup was measured by a LA-ICP-MS system and the reproducibility of the measured data was obtained. The Mo distribution was almost constant along the radius of a fuel except an increase at the periphery of the fuel. It showed a drop in reproducibility with relatively high deviation of measured values for the highest burnup fuel. To explain this, the state of molybdenum in a $UO_2$ matrix and its effect on the oxidation behavior of $UO_2$ were investigated. The low reproducibility was explained by the segregation of molybdenum, and the inhibition of oxidation by the molybdenum was also observed.

LOCAL BURNUP CHARACTERISTICS OF PWR SPENT NUCLEAR FUELS DISCHARGED FROM YEONGGWANG-2 NUCLEAR POWER PLANT

Ha, Yeong-Keong,Kim, Jung-Suck,Jeon, Young-Shin,Han, Sun-Ho,Seo, Hang-Seok,Song, Kyu-Seok Korean Nuclear Society 2010 Nuclear Engineering and Technology Vol.42 No.1

Spent $UO_2$ nuclear fuel discharged from a nuclear power plant (NPP) contains fission products, U, Pu, and other actinides. Due to neutron capture by $^{238}U$ in the rim region and a temperature gradient between the center and the rim of a fuel pellet, a considerable increase in the concentration of fission products, Pu, and other actinides are expected in the pellet periphery of high burnup fuel. The characterization of the radial profiles of the various isotopic concentrations is our main concern. For an analysis, spent nuclear fuels originating from the Yeonggwang-2 pressurized water reactor (PWR) were chosen as the test specimens. In this work, the distributions of some actinide isotopes were measured from center to rim of the spent fuel specimens by a radiation shielded laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS) system. Sampling was performed along the diameter of the specimen by reducing the sampling intervals from 500 ${\mu}m$ in the center to 100 ${\mu}m$ in the pellet periphery region. It was observed that the isotopic concentration ratios for minor actinides in the center of the specimen remain almost constant and increase near the pellet periphery due to the rim effect apart from the $^{236}U$ to $^{235}U$ ratio, which remains approximately constant. In addition, the distributions of local burnup were derived from the measured isotope ratios by applying the relationship between burnup and isotopic ratio for plutonium and minor actinides calculated by the ORIGEN2 code.

Elemental analysis by neutron induced nuclear reaction - Nuclear track method for the analysis of fissile materials

Yeong-Keong Ha,Hyung Yeol Pyo,Yong Joon Part,Kwang Yong Jee,Won Ho Kim 한국분석과학회 2005 분석과학 Vol.18 No.4

Effect of Ce doping on UO₂ structure and its oxidation behavior

Ha, Yeong-Keong,Lee, Jeongmook,Kim, Jong-Goo,Kim, Jong-Yun Elsevier 2016 JOURNAL OF NUCLEAR MATERIALS Vol.480 No.-

<P><B>Abstracts</B></P> <P>The structure of U<SUB>1-<I>y</I> </SUB>Ce<SUB> <I>y</I> </SUB>O<SUB>2</SUB> was studied in terms of added Ce cation. The oxygen vacancy, the oxidation state of cerium and uranium, and changes in the lattice parameter were investigated. Most Ce ions exist as tetravalent ions, which cause a lattice contraction due to the ionic radius. However, some Ce ions exist as trivalent Ce<SUP>3+</SUP> ions, causing the oxidation of U<SUP>4+</SUP> into higher oxidation states as well as a formation of oxygen vacancy for a charge balance. In addition, the effect of Ce on the oxidation of uranium dioxide was also studied by thermo-gravimetric analysis. The oxidation of Ce doped UO<SUB>2</SUB> proceeds through dominant path given as two step reaction U<SUB>1-<I>y</I> </SUB>Ce<SUB> <I>y</I> </SUB>O<SUB>2-δ</SUB> → ( <SUB> U 1 − y </SUB> Ce y 4 + )<SUB>4</SUB>O<SUB>9</SUB> → ( <SUB> U 1 − y </SUB> Ce y 4 + )<SUB>3</SUB>O<SUB>8</SUB>. However, for higher Ce content (<I>y</I> = 0.136 to 0.332), an alternative pathway is proposed as ( <SUB> U 1 − y </SUB> Ce y 4 + )<SUB>4</SUB>O<SUB>9</SUB> → ( <SUB> U 1 − y </SUB> Ce y 3 + )<SUB>4</SUB>O<SUB>9</SUB>. The increasing Ce content stabilizes the cubic (U<SUB>1-<I>y</I> </SUB>Ce<SUB> <I>y</I> </SUB>)<SUB>4</SUB>O<SUB>9</SUB> phase, prohibits the formation of a metastable tetragonal (U<SUB>1-<I>y</I> </SUB>Ce<SUB> <I>y</I> </SUB>)<SUB>3</SUB>O<SUB>7</SUB> phase, and inhibits the formation of (U<SUB>1-<I>y</I> </SUB>Ce<SUB> <I>y</I> </SUB>)<SUB>3</SUB>O<SUB>8</SUB> proportional to the Ce content.</P>

Micro Sampling System for Highly Radioactive Specimen by Laser Ablation

Sun-Ho Han,Yeong-Keong Ha,Ki-Chul Han,Yang-Soon Park,Kwang Youg Jee,Won Ho Kim 한국방사성폐기물학회 2005 방사성폐기물학회지 Vol.3 No.1

방사선차폐 laser ablation 시스템을 레이저, 미세영역의 영상 확인을 위한 이미지 시스템, XYZ 이동장치와 조절기, ablation chamber, manipulator 및 여러 가지 광학부품들로 구성하였다. Ablation용 레이저는 UOB 및 tircaloy 시편으로부터 효율적으로 시료를 채취할 수 있도록 266 nm(6 mJ)까지 파장 변환이 가능한 Nd:YAG 레이저를 선정하였으며, 이미지 시스템은 직경 50 m 크기의 crater를 판별할 수 있는 200 배율 이상의 규격을 갖춘 CCD 카메라로 선정하였다. 시편 미세이동장치는 XYZ방향으로 시편이동이 가능하고 최대 이동거리가 50 mm까지 , 그리고 최소 1m 씩 정확하게 움직일 수 있는 장치로 선정하였다. 구성된 각 단위기기들에 대하여 광학 정렬을 수행한 후, 시료채취 부위를 50 m씩 정확하게 이동하면서 레이저로 조사시킨 시료 표면을 CCD 카메라를 통하여 관찰한 결과, 표면에 생성된 crater는 원형임을 확인함으로써 단위기기별 성능을 확인할 수 있었다. Shielded laser ablation system composed of laser system, image analyser, XYZ translator with motion controller, ablation chamber, manipulator and various optics was designed. Nd:YAG laser which can be tunable from 1064 nm to 266 m was selected as light source. CCD camera(< 200) was chosen to analyze a crater less than 50 un in diameter. XYZ translator was composed of three linear stage which can travel 50 w with a minimum movement of 1 um and motion controller. Before the performance test, each part of system was optically aligned. To perform the ablation test, the specimen was ablated by 50 um interval and observed by image analyser The shape of crater was almost round, indicating laser beam has homogeneous energy distribution. The resolution and magnification of image system were compatible with the design.

An Evaluation of the Rate Constant for the Chemical Step in an ECE Type Reduction of $Vo^{2+}^-Diethylenetriaminepentaacetate

Ki-Suk Jung,Se Chul Sohn,Yeong Keong Ha,Tae Yoon Eom,Sock Sung Yun Korean Chemical Society 1991 Bulletin of the Korean Chemical Society Vol.12 No.2