Reliability Evaluation of ACP Components under a Radiation Environment

Hyo-Kik Lee,Kwang-Ho Yoon,Kwang-Mook Lim,Byung-Suk Park,Ji Sup Yoon 한국방사성폐기물학회 2007 방사성폐기물학회지 Vol.5 No.4

이 논문은 사용후핵연료 차세대관리공정(ACP)에 사용되는 주요부품에 대한 방사선영향에 대하여 다룬다. 평가대상 부품으로는 중요도가 높은 것들 중에서 선택하였는데, AC 서보모터, 포텐쇼미터, 열전대, 가속도계, CCD 카메라를 그 대상으로 하였다. AC 서보모터의 경우 ACP 핫셀 내 조작기에 여러개가 사용되고 있고, 공정장치의 일부에 사용되고 있다. 포텐쇼미터는 조작기 관절의 절대 각도를 측정하기 위해 사용된다. 열전대는 금속전환장치 등의 반응기 온도 측정을 위해 사용된다. 가속도계는 탈피복시 발생하는 이상을 사전에 감지하기 위한 용도로 탈피복장치에 부착되어 있고, CCD 카메라는 조작기와 함께 공정 휴지기간에 영상 In-situ 이상감시를 하기 위한 용도로 사용된다. 다양한 방사선 중 감마선은 전기, 전자 및 로봇 부품에 가장 치명적이라고 알려져 있으므로 본 연구에서는 Co-60선원을 사용하는 감마조사시설을 이용해 방사선 영향을 평가하였다. 방사선조사결과 CCD 카메라를 제외한 다른 부품들은 방사선에 매우 강인한 특성을 보였다. 누적조사선량에 대한 각 대상 부품의 고유한 특성변화 데이터를 얻었고, 대상 부품의 성능을 보장할 수 있는 기준인 손상분기점에 대한 평가 자료를 얻을 수 있었다 This study deals with the irradiation effects on some selected components which are being used in an Advanced Spent Fuel Conditioning Process (ACP). Irradiation test components have a higher priority from the aspect of their reliability because their degradation or failure is able to critically affect the performance of an ACP equipment. Components that we chose for the irradiation tests were the AC servo motor, potentiometer, thermocouples, accelerometer and CCD camera. ACP facility has a number of AC servo motors to move the joints of a manipulator and to operate process equipment. Potentiometers are used for a measurement of several joint angles in a manipulator. Thermocouples are used for a temperature measurement in an electrolytic reduction reactor, a vol-oxidation reactor and a molten salt transfer line. An accelerometer is installed in a slitting machine to forecast an incipient failure during a slitting process. A small CCD camera is used for an in-situ vision monitoring between ACP campaigns. We made use of a gamma-irradiation facility with cobalt-60 source for an irradiation test on the above components because gamma rays from among various radioactive rays are the most significant for electric, electronic and robotic components. Irradiation tests were carried out for enough long time for total doses to be over expected threshold values. Other components except the CCD camera showed a very high radiation hardening characteristic. Characteristic changes at different total doses were investigated and threshold values to warrant at least their performance without a deterioration were evaluated as a result of the irradiation tests.

촬상관타입의 원격모듈화 내방사선 카메라시스템 연구

백동현 한국정보전자통신기술학회 2018 한국정보전자통신기술학회논문지 Vol.11 No.6

The CCD camera is easily deteriorated by radiation, and an integrated camera using an image pickup tube is used in a high radiation area. We implemented a radiation camera system which is divided into a camera head using radiation-resistant electronic components and a remote control using weak radiation-resistant electronic components such as TR, IC, etc. According to the experimental results, the first damage of the electronic parts was IC for horizontal and vertical sync generation, and it was confirmed that if the radiation of 2×~ rad is accumulated, the normal function is lost. In addition, the signal transmission cable for remoteization has added an input/output buffer circuit and reduced the closed loop area of the shield and the cable to eliminate signal loss correction and noise. Therefore, it is expected that the maintenance cost will be greatly reduced and practical because only the camera head part can be used instead of replacing the entire system. CCD카메라는 방사선에 쉽게 열화되어 고방사선구역에서는 촬상관을 이용한 일체화된 카메라가 사용되고 있다. 이를 방사선에 강한 전자부품을 사용한 카메라헤드부와 방사선에 약한 TR, IC등을 사용한 원격제어부로 분리제작한 내방사선 카메라시스템을 구현하였다. 실험결과 전자부품 중 가장 먼저 손상된 것은 수평 및 수직 동기 발생 IC이었으며 2×105~106 rad의 방사선이 누적되면 정상적인 기능이 상실됨을 확인하였다. 또한 원격화를 위한 신호전송 케이블은 입출력 버퍼회로를 부가하고 쉴드와 케이블의 폐루프면적을 감소시켜 신호 손실보정 및 노이즈를 제거하였다. 따라서 전체의 시스템을 교체하는 것이 아니라 카메라 헤드부분만을 교체하여 사용할 수 있으므로 실용적이며 관리 유지비용이 많이 절감 될 것으로 기대된다.

Feasibility Study of a Lens-coupled Charge-Coupled Device Gamma Camera

이학재,이기성,정영준,배승빈,강정원,김정민 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.61

A charge-coupled device (CCD) is generally used in a digital camera as a light-collecting device such as a photomultiplier tube (PMT). Because of its low sensitivity and very high dark current, CCD have not been popularly used for gamma imaging systems. However, a recent CCD technological breakthrough has improved CCD sensitivity, and the use of a Peltier cooling system can significantly minimize the dark current. In this study, we investigated the feasibility of a prototype CCD gamma camera consisting of a CsI scintillator, optical lenses, and a CCD module. Despite electron-multiplying (EM) CCDs having higher performance, in this study, we built a cost-effective system consisted of low-cost components compared to EMCCDs. Our prototype detector consists of a CsI scintillator, two optical lenses, and a conventional Peltier-cooled CCD. The performance of this detector was evaluated by acquiring the sensitivity, resolution, and the modulation transfer function (MTF). The sensitivity of the prototype detector showed excellent linearity. With a 1 mm-diameter pinhole collimator, the full width at half-maximum (FWHM) of a 1.1 mm Tc-99m line source image was 2.85 mm. These results show that the developed prototype camera is feasible for small animal gamma imaging.

CCD 카메라를 이용한 지상원격탐사 기술 개발

김응남(Kim Eung Nam) 대한토목학회 2006 대한토목학회논문집 D Vol.26 No.2D

현재, 대규모 지역에 대한 환경문제를 감시하는 기술로서 위성원격탐사 기술이 활발히 이용되고 있다. 이는 위성원격탐사 기술이 비교적 넓은 지역을 평가하기에 적절한 기술이기 때문이다. 그러나 최근에 들어서는 도로, 댐, 공항 등과 같은 대규모적인 토목공사 후의 녹화지대나 녹화 법면의 식생감시 등 비교적 좁은 영역을 정밀하게 조사할 수 있는 원격탐사 기법에 대한 수요가 발생되고 있다. 본 연구에서는 시판의 CCD 카메라와 새롭게 개발된 특수한 카메라 장치 등을 사용한 지상형 원격탐사ㆍ저고도 원격탐사 기술을 개발하고자 하였다. 본 연구에서 얻어진 결과는 다음과 같다. 네가지 지상형 원격탐사 장비간의 상호비교 실험에 사용된 필터의 투과 특성을 조사할 수 있었고, 식생지수를 추출하는 화상형 분광반사계로서 근적외선 디지털 카메라가 유용함을 알 수 있었다. 그리고, 식생지수의 일중 변화현상을 실험을 통해 조사할 수 있었다. 마지막으로 새롭게 개발된 지상형 원격탐사 장비를 통해 산불 발생지역에서의 식생지수의 변화현상을 조사할 수 있었다. Recently, in the case of observing the global environment, satellite remote sensing technology has been important. It's because satellite remote sensing is valuable for assessing relatively large areas. But now, small scale remote sensing techniques are needed which can be applicable to the detail investigation of plant tree areas which afforest land after the large scale construction of roads, dams and airports. In this study, we tried to develop and propose a lower altitude sensing technique which can be used in ground remote sensing by using a CCD camera. As a result of this investigation the following can be concluded: We recognized the transference characteristics of filters which were used in comparative tests about the four ground remote sensing devices. We also found that the near-IR camera could be used for an imaging spectral radiometer in the extraction of the vegetation index. Furthermore, we found that the vegetation index has varied hour by hour during the day of the experiment. Finally, we brought about an increase phase of the NDVI in a forest fire, which caused considerable damage, by developing new ground remote sensing technology.

CCTV 카메라용 광학계 설계

이수천 한국안광학회 2008 한국안광학회지 Vol.13 No.1

목적: 본 논문은 CCTV 카메라용 렌즈 설계를 triplet형으로 광학 설계를 하였다. 방법: 초점거리를 56mm, 유효 경을 20mm 그리고 화각을 5o로 한 망원 렌즈 형태이고, 설계하고자 하는 카메라의 CCD array detector의 크기를 2/3인치로 하였다. 결과: 광학계의 성능은 ray-fan과 spot diagram 그리고 회절 광학적인 MTF를 계산하여 평가하였 고, 파장은 Fraunhofer C, d 및 F-line에 대해 achromat 되었으며 MTF 값도 tangential과 sagittal MTF 모두 50 line pairs/mm의 공간 주파수에 70% 정도가 나왔다. 결론: triplet형으로 비교적 저가 보급형 감시용 목적 CCTV 카메라 를 설계하였고 충분히 실용적이라 생각된다. Purpose: This study is to design a triplet optical system for CCTV camera lens. Methods: It was a telescopic lens with 5o field angle, 56 mm focal length, 20 mm diameter, and 2/3 inches sized CCD array detector. Results: The performance of the subject optical system was evaluated by applying ray fan, spot diagram, and diffraction optical MTF. The wavelength was achromatized at Fraunhofer C, d and F-line, and both MTF and tangential & sagittal MTF shows more than 70% at spatial frequency of 50 linepairs/mm. Conclusions: The marketable triplet optical system for CCTV camera was designed and its utility was considered.

Development of an All-in-one Gamma Camera/CCD System for Safeguard Verification

김현일,안수정,정용현,곽성우 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.12

For the purpose of monitoring and verifying efforts at safeguarding radioactive materials in variousfields, a new all-in-one gamma camera/charged coupled device (CCD) system was developed. Thiscombined system consists of a gamma camera, which gathers energy and position information ongamma-ray sources, and a CCD camera, which identifies the specific location in a monitored area. Therefore, 2-D image information and quantitative information regarding gamma-ray sources canbe obtained using fused images. A gamma camera consists of a diverging collimator, a 22 × 22array CsI(Na) pixelated scintillation crystal with a pixel size of 2 × 2 × 6 mm3 and HamamatsuH8500 position-sensitive photomultiplier tube (PSPMT). The Basler scA640-70gc CCD camera,which delivers 70 frames per second at video graphics array (VGA) resolution, was employed. Performance testing was performed using a Co-57 point source 30 cm from the detector. Themeasured spatial resolution and sensitivity were 4.77 mm full width at half maximum (FWHM) and7.78 cps/MBq, respectively. The energy resolution was 18% at 122 keV. These results demonstratethat the combined system has considerable potential for radiation monitoring.

비 가시 환경에서의 적외선 열화상 카메라 가시도

조재완(Jai Wan Cho),최영수(Young Soo Choi),정경민(Kyung Min Jeong) 제어로봇시스템학회 2017 제어·로봇·시스템학회 논문지 Vol.23 No.6

In this paper, the visibility test results of thermal infrared cameras under dense fog environments are described. When a severe accident occurs in a nuclear power plant, cold water is ejected downward to cool the reactor pressure vessel through the nozzle of the core spray system. When this cold water collides with the hot reactor structures, dense aerosol (fog) is formed, severely diminishing the visibility in the reactor containment building where the reactor pressure vessel is located. It is impossible to acquire critical, such as water level, reactor pressure, temperature, and gamma ray dose rate, through image interpretation using a CCD/CMOS camera system based on visible (400-700 nm) wavelengths. As an alternative to the CCD/CMOS camera, we consider the thermal infrared camera based on the NWIR (3-5 um) or LWIR (7-14 um) wavelength spectrum. To test the monitoring performance of the thermal infrared camera under dense fog environments, we created a test facility (2.5 m × 2.5 m × 15 m, WHD) into which fog was injected until the concentration of the fog was saturated. The hot plates including the heating source were located at far (~ 10 m) and near (~ 3 m) positions inside the test facility. The thermal infrared camera monitored the hot plates, which were 3-10 m away, under the dense fog environment. We compared the detection performance of the thermal infrared camera with the monitoring perfromance of the CCD camera under the same visibility conditions.

삼각법기반 구조화된 격자 패턴 캘리브레이션

주기세 한국정보통신학회 2004 한국정보통신학회논문지 Vol.8 No.5

지금까지 3차원 정보를 얻기 위하여 CCD카메라, 레이저, 구조화된 격자 발생기 등과 같은 여러 센서들이 사용되어져 왔지만 대부분의 캘리브레이션 알고리즘들은 많은 메모리와 실험 시간을 필요로 하기 때문에 비효율적이었다. 본 논문에서는 실세계 상의 3차원 정보를 얻기 위한 삼각법을 기반으로한 구조화된 격자 캘리브레이션 알고리즘이 소개된다. CCD카메라와 수평으로 설치된 구조화된 격자 패턴 생성기로부터 생성된 빔들이 캘리브레이션 면에 사영된다. CCD 카메라는 대상물과 사영된 빔이 교차한 평면을 측정한다. 그리고 3차원 데이터는 측정된 값과 캘리브레이션 데이터를 이용하여 계산된다. 본 논문에서 제안한 방범은 3차원 정보를 간단한 삼각법으로 획득하였기 때문에 효율적인 측정시간과 메모리 절약의 이점을 가지고 있다. So far, many sensors such as a structured grid pattern generator, a laser, and CCD camera to obtain 3D information have been used, but most of algorithms for a calibration are inefficient since a huge memory and experiment time are required. In this paper, the calibration algorithm of a structured grid pattern based on triangulation method is introduced to calculate 3D information in the real world. The beams generated from structured grid pattern generator established horizontally with the CCD camera are projected on the calibration plat. A CCD camera measures the intersection plane of a projected beam and an object plane. The 3D information is calculated using measured and calibration datum. This proposed method in this paper has advantages such as a memory saving and an efficient experimental time since the 3D information is obtained simply the triangulation method.

디지털카메라의 이미지캡쳐 시스템에 관한 연구

김종욱 啓明專門大學 産業開發硏究所 2000 啓明硏究論叢 Vol.18 No.2

사진제작의 새로운 방식인 디지털 카메라촬영 기술은 상당히 빠른 속도로 발전하고 있다. 오늘날 대부분 사진관련 시스템은 전통적 은염사진을 기본으로 하고 있으나 빠른 속도로 디지털 이미지 처리방식으로 전환되고 있는 상황을 고려한다면 디지털 카메라의 구조와 특성을 이해하고 앞으로 다가올 디지털 세대에 어떻게 사진가가 대처하여야 할 것인가는 중요한 과제이다. 본 논문에서는 현재 시판되고 있는 여러 종류의 디지털카메라 촬영 방식의 구조적 특성을 중심으로 기존의 은염사진제작 방식에서 변화와 차이점을 알아보았다. A new technique of photography using digital camera is rapidly developing nowadays. The new technique of photography using digital image process is totally different in technology from the existent system of photography which relies on traditional silver image process. Along with current development of information technology, digital photography will take the lion's share in the field of photography in the near future. Thus, it becomes prerequisite for photographers to understand the structure and characteristic of digital cameras. This paper explores the structural difference between traditional s3ver image processing and new digital image processing photography by examining the photographic technique and characteristic of various digital cameras in use.

CCD카메라와 레이저 센서를 조합한 지능형 로봇 빈-피킹에 관한 연구

신찬배(Chan-Bai Shin),김진대(Jin-Dae Kim),이재원(Jeh-Won Lee) 대한전기학회 2007 대한전기학회 학술대회 논문집 Vol.2007 No.4

In this paper we present a new visual approach for the robust bin-picking in a two-step concept for a vision driven automatic handling robot. The technology described here is based on two types of sensors: 3D laser scanner and CCD video camera. The geometry and pose(position and orientation) information of bin contents was reconstructed from the camera and laser sensor, these information can be employed to guide the robotic arm. A new thinning algorithm and constrained hough transform method is also explained in this paper. Consequently, the developed bin-picking demonstrate the successful operation with 3D hole object.