• 제목/요약/키워드: exposure unit

검색결과 405건 처리시간 0.022초

고리1호기 증기발생기 제염해체 시 작업자 피폭선량 평가 및 저감화 방안 (The Assessment and Reduction Plan of Radiation Exposure During Decommissioning of the Steam Generator in Kori Unit 1)

  • 손영직;박상준;변지향;안석영
    • 방사성폐기물학회지
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    • 제16권3호
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    • pp.377-387
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    • 2018
  • 대한민국 첫 상업원전인 고리1호기는 40년간의 성공적인 운전을 끝내고 2017년 6월 18일 영구정지 되었다. 고리1호기는 본격적인 해체에 앞서 터빈건물에 폐기물처리시설 건설을 계획하고 있다. 각종 방사성폐기물은 폐기물처리시설에서 제염, 해체, 절단, 용융되어 자체처분 되거나 방사성폐기물 처분장으로 보내 진다. 해체폐기물 중 대형금속방사성폐기물은 주로 1차 계통측 기기들로 높은 방사능을 띄고 있어 해체활동 중 작업자의 피폭관리가 필요하다. 본 논문에서는 대형금속방사성폐기물 중 크기가 가장 크고 형상이 복잡한 증기발생기를 선정하여 RESRAD-RECYCLE 코드를 이용하여 작업자 피폭선량을 평가하고 저감화 방안을 수립 하고자 한다.

Molecular and Morphological Evidence of Hepatotoxicity after Silver Nanoparticle Exposure: A Systematic Review, In Silico, and Ultrastructure Investigation

  • Sooklert, Kanidta;Wongjarupong, Asarn;Cherdchom, Sarocha;Wongjarupong, Nicha;Jindatip, Depicha;Phungnoi, Yupa;Rojanathanes, Rojrit;Sereemaspun, Amornpun
    • Toxicological Research
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    • 제35권3호
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    • pp.257-270
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    • 2019
  • Silver nanoparticles (AgNPs) have been widely used in a variety of applications in innovative development; consequently, people are more exposed to this particle. Growing concern about toxicity from AgNP exposure has attracted greater attention, while questions about nanosilver-responsive genes and consequences for human health remain unanswered. By considering early detection and prevention of nanotoxicology at the genetic level, this study aimed to identify 1) changes in gene expression levels that could be potential indicators for AgNP toxicity and 2) morphological phenotypes correlating to toxicity of HepG2 cells. To detect possible nanosilver-responsive genes in xenogenic targeted organs, a comprehensive systematic literature review of changes in gene expression in HepG2 cells after AgNP exposure and in silico method, connection up- and down-regulation expression analysis of microarrays (CU-DREAM), were performed. In addition, cells were extracted and processed for transmission electron microscopy to examine ultrastructural alterations. From the Gene Expression Omnibus (GEO) Series database, we selected genes that were up- and down-regulated in AgNPs, but not up- and down-regulated in silver ion exposed cells, as nanosilver-responsive genes. HepG2 cells in the AgNP-treated group showed distinct ultrastructural alterations. Our results suggested potential representative gene data after AgNPs exposure provide insight into assessment and prediction of toxicity from nanosilver exposure.

An Estimation of Loss Ratio Based on Empirical Bayes Credibility

  • Lee, Kang Sup;Lee, Hee Chun
    • Communications for Statistical Applications and Methods
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    • 제9권2호
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    • pp.381-388
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    • 2002
  • It has been pointed out that the classical credibility model used in Korea since the beginning of 1990's lacks in objectiveness. Recently, in order to improve objectiveness, the empirical Bayes credibility model utilizing general exposure units like the number of claims and premium has been employed, but that model itself is not quite applicable in the country like Korea whose annual and classified empirical data are not well accumulated and even varied severely. In this article, we propose a new and better model, Based on the new model, we estimate both credibility and loss ratio of each class for fire insurance plans by Korean insurance companies. As a conclusion, we empirically make sure analysis that the number of claims is a more reasonable exposure unit than premium.

방사선발생장치 교육을 위한 시뮬레이터의 개발과 유용성 평가 (Development and Usefulness Evaluation of Simulator for Educational Radiation Generator)

  • 서정민
    • 대한방사선기술학회지:방사선기술과학
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    • 제44권6호
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    • pp.591-597
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    • 2021
  • In the present study, we developed virtual reality education contents for radiation generator on radiation education field. The radiation generator was divided by module and even the X-ray exposure part was manufactured in detail for designing 3D models. The mechanical details of the X-ray exposure part, the function of adjusting field size of the X-ray, the function of moving the exposure part, and the demonstrating the principle of the X-ray tube were applied. For developing VR contents, the Unreal Engine was used. To evaluate the usefulness of virtual reality content, we used t-test by SPSS. The group used the simulator showed significantly higher levels of understanding of X-ray generation, X-ray irradiation unit composition, irradiation field size adjustment, irradiation unit position adjustment, and overall composition and function. We believe that this VR contents will be used well with radiation safe environment.

External exposure specific analysis for radiation worker in reuse of containment building for Kori Unit 1

  • Byon, Jihyang;Park, Sangjune;Kim, Yangjin;Ahn, Seokyoung
    • Nuclear Engineering and Technology
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    • 제54권5호
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    • pp.1781-1788
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    • 2022
  • The containment building Kori Unit 1 may require sequential steps for full decommissioning. This study assumes that the containment building is to be used as an auxiliary building that handles nuclear power systems and materials during decommissioning before conversion into a greenfield. Through the derivation of guidelines and dose evaluation, it was confirmed whether the radiation workers were satisfied with the ALARA decision. The specific modeling of the external radiation exposure was performed based on the facility investigation procedures. The external radiation specific derived concentration guideline levels (DCGLs) for radiation workers in containment building were obtained using the RESRAD-BUILD code and were applied to the VISIPLAN 3D ALARA Planning Tool code to calculate the working dose and check worker safety. The derivation of site-specific and realistic DCGLs and dose evaluation via 3D modeling can contribute to the scenario development for the decommission and remediation of containment building.

Study on Consumer Exposure to Sun Spray and Sun Cream in South Korea

  • Oh, Mihyun;Kim, Seoyoung;Han, Jieun;Park, Sodam;Kim, Go Un;An, Susun
    • Toxicological Research
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    • 제35권4호
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    • pp.389-394
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    • 2019
  • When conducting risk assessments of cosmetic ingredients, it is important that reliable exposure information is obtained for cosmetic products. As cosmetics are becoming more diverse, continuous effort must be made to obtain exposure data that reflect their growth and usage trends. The usage pattern of cosmetics, such as the application area and amount used, may differ by product type and also by country. We conducted a survey to compare the amount of sun spray and sun cream used in a usage environment in South Korea. The study was conducted on Haeundae Beach, one of the most popular beaches in South Korea. A total of 1,255 beachgoers participated in this study; 604 and 651 participants used the sun spray and sun cream, respectively, while sunbathing and enjoying water activities on the beach for one day. Exposure was analyzed following a probabilistic method. On comparing all subjects, it was found that the group that used sun spray (mean: 44.52 g/day) used significantly more product (p = 0.000) than those who used sun cream (mean: 20.51 g/day). By analyzing the daily exposure of sun spray and sun cream per unit body weight according to age and gender, the exposure amount of sun spray and sun cream was found to be highest among 2~9 year-old girls (mean for sun spray: 2.51 g/kg/day, p95: 5.50 g/kg/day, mean for sun cream: 0.79 g/kg/day, p95: 1.79 g/kg/day). The amount of sun spray used is approximately twice that of sun cream. Among both the sun spray and sun cream groups, the exposure amount per unit body weight was highest in girls younger than 10. These factors should be considered when conducting risk assessments of sun spray and sun cream.

원자력 사고후 장기피폭에 대한 개입을 위한 피폭선량 금전가 산정의 개선된 방법론 (An Improved Methodology of Monetary Values of the Unit Collective Dose for Intervention Against Long-Term Exposure Following a Nuclear Accident)

  • 황원태;김은한;서경석;최영길;한문희
    • Journal of Radiation Protection and Research
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    • 제27권2호
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    • pp.77-80
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    • 2002
  • 원자력시설의 정상 운영시 일반인에 대한 단위 집단선량의 금전가 (피폭선량 금전가) 모델을 기본으로, 사고후 만성피폭에 대해 보다 적용 타당한 모델을 제안하였다. 아울러 우리나라 경제 환경자료를 사용하여 제안된 모델에 근거하여 평가한 피폭선량 금전가를 정상 운영시로부터 유도된 값을 수정없이 그대로 사고후 만성 피폭에 적용한 값과 비교, 분석하였다. 제안된 방법론에 근거할 경우 집단선량은 같다하더라도 피폭받은 집단내 개인선량의 불균일성 차이에 따라 피폭선량 금전가는 상당히 다르게 나타났다. 또한 할인율도 피폭선량 금전가 결정에 있어서 중요한 요소로 작용하였다.

신생아 집중치료실에서 침습 칸디다 감염의 예방 (Prevention of Invasive Candida Infections in the Neonatal Intensive Care Unit)

  • 김천수
    • Pediatric Infection and Vaccine
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    • 제18권1호
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    • pp.15-22
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    • 2011
  • Invasive Candida infections (ICI) have become the third most common cause of late-onset infection among premature infants in the neonatal intensive care unit (NICU). Risk factors include birth weight less than 1,000 g, exposure to more than two antimicrobials, third generation cephalosporin exposure, parenteral nutrition including lipid emulsion, central venous catheter, and abdominal surgery. Candida colonization of the skin and gastrointestinal tract is an important first step in the pathogenesis of invasive disease. Strict infection control measures against the infection should be done in the NICU. The following practices are likely to contribute to reducing the rate of ICI: (1) restriction of broad-spectrum antibiotics, antacids and steroid; (2) introduction of early feeding and promoting breast milk. Fluconazole prophylaxis may be an effective control measure to prevent Candida colonization and infections in individual units with high incidence of fungal infection. In addition, there is a need of further data including the development of resistant strains and the effect on long-term neurodevelopmental outcomes of infants exposed to drugs before the initiation of routine application of antifungal prophylaxis in the NICU.

간접촬영용 X-선 발생장치 성능 평가 (An ability test for the use of indirect radiographic unit)

  • 임인철
    • 대한방사선기술학회지:방사선기술과학
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    • 제27권4호
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    • pp.37-41
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    • 2004
  • 목 적 : 측정을 통한 장치의 성능관리 평가로 임상실무에서의 능력배양과 정확한 관전압, 조사시간, 출력선량을 측정하는 기술을 익히고 병원에서 사용 중인 간접촬영용 X-선 발생장치 성능현황을 파악하기 위함이다. 재료 및 방법 : 관전압, 조사시간, 출력선량 측정기를 이용하여 10개 대학병원 간접촬영용 X-선 발생장치(원내,외 각 10대)를 이용하였다. 결 과 : 관전압 정확도 시험 PAE 판정에 의해 부적합한 간접촬영기는 3대가 나왔으며, 조사시간의 정확도 시험에서는 2대, 또한 조사선량의 재현성 시험에서도 조사선량에 대한 변동계수를 계산한 결과 3대가 나왔다. 3가지 성능검사에서 원외(이동차량)의 부적합한 간접촬영기는 5대, 원내는 3대로 원외(이동차량)의 간접촬영기가 원내보다 부적합한 것이 높게 나타났다. 결 론 : 간접촬영기의 성능을 일정하게 유지함으로서 방사선 피폭경감, 화질관리, 재촬영 감소 등에 의해 환자에게 양질의 의료서비스를 제공할 수 있는 여건을 마련할 수 있을 것이다. 따라서 정기적인 성능검사가 필요하다고 사료된다.

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