원전 증기발생기 와전류검사 장치의 전기적 특성 측정

이희종(Hee-Jong Lee),조찬희(Chan-Hee Cho),유현주(Hyun-Joo Yoo),문균영(Gyoon-Young Moon),이태훈(Tae-Hun Lee) 한국비파괴검사학회 2013 한국비파괴검사학회지 Vol.33 No.5

원전 증기발생기는 원자로 냉각재 계통에서 발생한 열에너지를 터빈 계통의 주급수에 전달하여 터빈을 회전시키기 위한 증기를 생산하는 일종의 열교환기이다. 증기발생기 전열관의 손상은 증기발생기의 구조적 및 누설 건전성 유지 능력을 저해시키기 때문에 주기적으로 와전류검사를 수행하여 전열관의 건전성을 평가한다. 증기발생기 전열관의 건전성 평가는 보통 원자로 연료 재장전 기간 중에 수행된다. 현재 국내 증기발생기 전열관에 적용되는 와전류검사는 KEPIC 및 ASME 코드 요건에 따라 수행되며, 와전류검사 수행에 필요한 검사 시스템은 와전류검사 장치와 수집된 신호를 평가하기 위한 평가 프로그램으로 구성된다. 검사에 적용되는 와전류검사 시스템을 구성하는 핵심기기인 와전류검사 장치는 ASME 및 KEPIC 코드에서 총 고조파 왜곡율, 입출력 임피던스, 증폭기 직선성 및 안정성, 위상 직선성, 대역폭 및 복조필터 응답, 디지털 변환, 채널 간섭 등과 같은 전기적 특성을 측정하도록 규정하고 있다. 이에 따라 본 논문에서는 국내 최초로 개발한 원전 증기발생기 와전류검사 장치의 전기적 특성 측정을 위한 ASME 및 KEPIC 코드 요건을 설명하고, 이 요건에 따른 증기발생기 와전류검사 장치의 전기적 특성의 측정 결과를 제시하였다. A steam generator in nuclear power plant is a heatexchager which is used to convert water into steam from heat produced in a nuclear reactor core, and the steam produced in steam generator is delivered to the turbine to generate electricity. Because of damage to steam generator tubing may impair its ability to adequately perform required safety functions in terms of both structural integrity and leakage integrity, eddy current testing is periodically performed to evaluate the integrity of tubes in steam generator. This assessment is normally performed during a reactor refueling outage. Currently, the eddy current testing for steam generator of nuclear power plant in Korea is performed in accordance with KEPIC & ASME Code requirements, the eddy current testing system is consists of remote data acquisition unit and data analysis program to evaluate the acquired data. The KEPIC & ASME Code require that the electrical properties of remote data acquisition unit, such as total harmonic distortion, input & output impedance, amplifier linearity & stability, phase linearity, bandwidth & demodulation filter response, analog-to-digital conversion, and channel crosstalk shall be measured in accordance with the KEPIC & ASME Code requirements. In this paper, the measurement requirements of electrical properties for eddy current testing instrument described in KEPIC & ASME Code are presented, and the measurement results of newly developed eddy current testing instrument by KHNP(Korea Hydro & Nuclear Power Co., LTD) are presented.

와전류검사 기술을 적용한 가압중수로 원전 압력관 비파괴검사

이희종(Hee-Jong Lee),최성남(Sung-Nam Choi),조찬희(Chan-Hee Cho),유현주(Hyun-Joo Yoo),문균영(Gyoon-Young Moon) 한국비파괴검사학회 2014 한국비파괴검사학회지 Vol.34 No.3

중수로 원자로는 한 개의 원자로용기로 구성된 경수로와는 달리 약 380여개의 연료채널(fuel channel)로 구성되어 있다. 연료채널을 구성하는 압력유지 기기인 압력관(pressure tube)은 지르코니움 합금(Zr-2.5wt% Nb) 재질로서 치수는 내경이 103.4 mm, 두께가 약 4.19 mm, 길이가 6.36 m인 튜브 형태의 관이다. 압력관은 내부에 핵연료 다발과 냉각재가 내장되며 압력관의 기능은 연료를 지지하고 열수송 유체인 중수(D₂O)를 이송한다. 압력관의 단순한 기하학적인 형상으로 인하여 자동화 비파괴검사가 가능하고 접근성이 우수하다. 연료 채널은 경수로형 원전과 동일하게 설치전과 운전중에 원자력안전위원회 법령 요건에 따라 주기적으로 엄격한 비파괴검사를 수행하여 건전성을 확인한다. 연료채널의 주기적 비파괴검사에는 초음파탐상 및 와전류탐상검사 기법을 적용한 체적 비파괴검사 기술이 적용된다. 이중에서 와전류탐상검사 기법은 초음파탐상검사에서 검출된 결함의 확인을 위한 보충검사기술로 적용되고 있지만 표면결함에 대한 검출능이 초음파탐상검사 기법보다 우수한 장점을 가지고 있다. 본 논문에서는 압력관 내부 표면 비파괴검사에 적용되고 있는 와전류탐상검사 기술의 압력관 내면에 발생할 수 있는 결함의 검출 및 깊이 측정 특성에 대한 연구결과를 기술하였다. 즉, 와전류검사 기술은 압력관 내면에 발생할 수 있는 아주 미세한 결함을 매우 우수한 분해능으로 검출할 수 있으므로 초음파탐상검사 결과 확인을 위한 보충기술로서 매우 유용하지만, 결함의 깊이 측정은 오차가 매우 크게 발생하므로 결함 깊이 측정에는 적합하지 않고 오직 표면결함 검출에만 적용하는 것이 바람직하다. A pressurized heavy water reactor (PHWR) core has 380 fuel channels contained and supported by a horizontal cylindrical vessel known as the calandria, whereas a pressurized water reactor (PWR) has only a single reactor vessel. The pressure tube, which is a pressure-retaining component, has a 103.4 mm inside diameter × 4.19 mm wall thickness, and is 6.36 m long, made of a zirconium alloy (Zr-2.5 wt% Nb). This provides support for the fuel while transporting the D₂O heat-transfer fluid. The simple tubular geometry invites highly automated inspection, and good approach for all inspection. Similar to all nuclear heat-transfer pressure boundaries, the PHWR pressure tube requires a rigorous, periodic inspection to assess the reactor integrity in accordance with the Korea Nuclear Safety Committee law. Volumetric-based nondestructive evaluation (NDE) techniques utilizing ultrasonic and eddy current testing have been adopted for use in the periodic inspection of the fuel channel. The eddy current testing, as a supplemental NDE method to ultrasonic testing, is used to confirm the flaws primarily detected through ultrasonic testing, however, eddy current testing offers a significant advantage in that its ability to detect surface flaws is superior to that of ultrasonic testing. In this paper, effectiveness of flaw detection and the depth sizing capability by eddy current testing for the inside surface of a pressure tube, will be introduced. As a result of this examination, the ET technique is found to be useful only as a detection technique for defects because it can detect fine defects on the surface with high resolution. However, the ET technique is not recommended for use as a depth sizing method because it has a large degree of error for depth sizing.

Synthesis and Biological Evaluation of Phosphonate Analogues of 1 $\alpha$, 25-Dihydroxyvitamin $D_3$

Han, Gyoon-hee The Pharmaceutical Society of Korea 2000 Archives of Pharmacal Research Vol.23 No.3

A new series of phosphonate side chain analogues of 1$\alpha$,25-dihydroxyvitamin $D_3$ (1) have been synthesized. Antiproliferative activities of theses analogues (8a,b and 9a,b) using human keratinocyte cell shows that analogues which have natural A-ring show higher activity than unnatural A-ring series and almost equally active to 1 $\alpha$,25-Dihydroxyvitamin $D_3$(1) at 1 $\mu$M level.

궤양성 대장염 환자에서 발생한 우측 대장의 위막성 대장염 1예

주희린 ( Hee Rin Joo ),김태오 ( Tae Oh Kim ),김태균 ( Tae Gyoon Kim ),서은희 ( Eun Hee Seo ),박종하 ( Jongha Park ),박승하 ( Seung Ha Park ),양성연 ( Sung Yeon Yang ),문영수 ( Young Soo Moon ) 대한장연구학회 2011 Intestinal Research Vol.9 No.2

Clostridium difficile (C. difficile) is a cytotoxin-producing anaerobic gram-positive rod that is responsible for pseudomembranous colitis (PMC). The incidence of C. difficile is increasing in ulcerative colitis (UC) and inflammatory bowel disease patients and is associated with a more severe course, a longer hospital stay, higher financial costs, a greater likelihood of colectomy, and high mortality. PMC may occur anywhere along the intestinal tract, but it is often found in the distal colon. PMC involving the proximal colon with rectosigmoid sparing is rarely reported in patients with UC. We describe the case of a 35-year-old woman in remission from UC who presented with frequent diarrhea and abdominal pain. She was treated with ciprofloxacin for infectious enterocolitis at a local hospital; however, her symptoms did not improve. A colonoscopy revealed yellow-white plaques with edematous,erythematous from the proximal ascending colon to the cecum, and feces positive for C. difficile toxin. She was treated with metronidazole (500 mg, three times a day) for two weeks, and improved rapidly. Physicians should carefully examine the entire colon via colonoscopy, and perform stool exams for C. difficile in patients with UC who have been treated with antibiotics and in those who develop prolonged diarrhea despite medical treatment. (Intest Res 2011;9:144-147)

A FACILE SYNTHESIS OF 2-AMINOTHIAZOLO[5,4-b]PYRIDINES AND 2-AMINOBANZOXAZOLES VIA CYCLIZATION OF THIOUREAS

Yoon, Ju-Hee,Song, Hyun-Min,Kim, Sang-Wong,Han, Gyoon-Hee,Park Choo, Hea-Young 이화여자대학교 약학연구소 2005 藥學硏究論文集 Vol.- No.16

2-Aminothiazolo[5,4-b]pyridines and 2-aminobenzoxazoles have been synthesized from 2-hydroxy-3-thioureidopyridine and 2-hydroxy-3-thioureidobenzene respectively via acid catalyzed cyclization, which were prepared by the reaction of isothiocyanates with 2-hydroxy-3-aminopyridine or 2-aminophenol, The hydroxyl group of N-(2-hydroxy-5-phenyl)- N'-phenyl thiourea reacted as nucleophile to thioureido carbon to give 2-aminobenzoxazoles, whereas that of N-(2-hydroxypyridino)-N'-Phenylthiourea was reacted as leaving group upon nuclephillic sulfur of thiourea group in the presence of trifluoroacetic acid or phosphoric acid.

Differential Gene Expression of Periodontal Ligament Cells After Loading of Static Compressive Force

Lee, Yeon-Hee,Nahm, Dong-Seok,Jung, Youn-Kwan,Choi, Je-Yong,Kim, Sahng Gyoon,Cho, Michael,Kim, Myung-Hee,Chae, Chang-Hoon,Kim, Seong-Gon Wiley (John WileySons) 2007 Journal of periodontology Vol.78 No.3

BOOMING INDEX DEVELOPMENT IN A PASSENGER CAR

Hee-Chang Chae(채희창),Sang-Kwon Lee(이상권),Dong-Chul Park(박동철),Seung-Gyoon Jung(정승균) 한국소음진동공학회 2002 한국소음진동공학회 학술대회논문집 Vol.2002 No.11(영문초록)

Giant Cell Tumor with Secondary Aneurysmal Bone Cyst Shows Heterogeneous Metabolic Pattern on ¹⁸F-FDG PET/CT: A Case Report

Park, Hee Jeong,Kwon, Seong Young,Cho, Sang-Geon,Kim, Jahae,Song, Ho-Chun,Kim, Sung Sun,Yoon, Yeon Hong,Park, Jin Gyoon The Korea Society of Nuclear Medicine 2016 핵의학 분자영상 Vol.50 No.4

Giant cell tumor (GCT) is a generally benign bone tumor accounting for approximately 5 % of all primary bone neoplasms. Cystic components in GCTs that indicate secondary aneurysmal bone cysts (ABCs) are reported in 14 % of GCTs. Although both of them have been described separately in previous reports that may show considerable fluorodeoxyglucose (FDG) uptake despite their benign nature, the findings of GCT with secondary ABC on $^{18}F$-FDG positron emission tomography/computed tomography (PET/CT) have not been well-known. We report a case of GCT with secondary ABC in a 26-year-old woman. $^{18}F$-FDG PET/CT revealed a heterogeneous hypermetabolic lesion in the left proximal femur with the maximum standardized uptake value of 4.7. The solid components of the tumor showed higher FDG uptake than the cystic components. These observations suggest that the ABC components in GCTs show heterogeneous metabolic patterns on $^{18}F$-FDG PET/CT.

Diagnosis and Treatment of Discoid Meniscus

( Jae-gyoon Kim ),( Seung-woo Han ),( Dae-hee Lee ) 대한슬관절학회 2016 대한슬관절학회지 Vol.28 No.4

There is a greater incidence of discoid meniscus in Asian countries than in Western countries, and bilateral discoid menisci are also common. The discoid meniscus may be a congenital anomaly, and genetics or family history may play a role in the development of discoid menisci. Because the histology of discoid meniscus is different from that of normal meniscus, it is prone to tearing. Individuals with a discoid meniscus can be asymptomatic or symptomatic. Asymptomatic discoid menisci do not require treatment. However, operative treatment is necessary if there are symptoms. Total meniscectomy leads to an increased risk of osteoarthritis. Therefore, total meniscectomy is generally reserved for rare unsalvageable cases. Partial meniscectomy (saucerization) with preservation of a stable peripheral rim combined with or without peripheral repair is effective, and good short-, mid-, and long-term clinical results have been reported.

Sterols of sewage indicators in marine sediments of Jinhae Bay, Korea

Choi, Hee-Gu,Kim, Sang-Gyoon,Kim, Sang-Soo,Moon, Hyo-Bang,Lee, Pil-Yong,Park, Chung-Kil The Korean Society of Oceanography 2002 Journal of the Korean Society of Oceanography Vol.37 No.2

The ${\Delta}^5$ sterols were measured in be sediments of Jinhae Bay surrounded by industrial cities to assess the sewage-derived contamination. The total concentrations of total sterols ranged from 2.03 to 19.56 ${\mu}g/g$ dry wt. The principal sterol was cholesterol with a contribution of more than 50% to total sterols. Coprostanol, providing an indication of long-term sewage loads, was found in all sediment samples and the concentrations were 0.03-3.86 ${\mu}g/g$ dry wt, accounting for 1-26% to total sterols. The cluster analysis of sampling stations indicated that the sewage-derived contamination was localized in inner Masan Bay.