• Title/Summary/Keyword: 방사조사

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Evaluating Activation for 50 MeV Cyclotron Irradiation Service using Monte Carlo Method and Inventory Code (50 MeV 사이클로트론 조사 서비스로 인한 방사화 평가)

  • Kim, Sangrok;Kim, Gi-sub;Heo, Jaeseung;Ahn, Yunjin
    • Journal of the Korean Society of Radiology
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    • v.15 no.4
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    • pp.415-427
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    • 2021

  • Korea Institute of Radiological and Medical Sciences has provided various beam irradiation services to researchers using a 50 MeV cyclotron beam line. In particular, since the neutron beam service uses the nuclear reaction between protons and beryllium, the possibility of activation of the irradiated sample increases by using a high current. In this study, MCNP 6.2 and FISPACT-II 4.0 were used to evaluate the possible activation during the 35 MeV 20 ㎂ neutron beam service, which is preferred by the researchers. As a result of the calculation, if the iron, copper, and tungsten samples were irradiated for more than 1 hour, long-lived radioisotopes were produced and their radioactivity exceeded the standard level for self-disposal. Under the conditions of 2 hours of daily irradiation, no activation occurred in the building materials, and the internal exposure of workers due to air activation inside the irradiation room was very insignificant. And when this air was discharged to environment, the radioactivity including this air was also satisfied the emission standard.

  • https://doi.org/10.7742/jksr.2021.15.4.415 인용 PDF KSCI HTML

Review of Site Characterization Methodology for Deep Geological Disposal of Radioactive Waste (방사성폐기물의 심층 처분을 위한 부지특성조사 방법론 해외 사례 연구)

  • Park, Kyung-Woo;Kim, Kyung-Su;Koh, Yong-Kwon;Jo, Yeonguk;Ji, Sung-Hoon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.15 no.3
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    • pp.239-256
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    • 2017

  • In the process of site selection for a radioactive waste disposal, site characterization must be carried out to obtain input parameters to assess the safety and feasibility of deep geological repository. In this paper, methodologies of site characterization for radioactive waste disposal in Korea were suggested based on foreign cases of site characterization. The IAEA recommends that site characterization for radioactive waste disposal should be performed through stepwise processes, in which the site characterization period is divided into preliminary and detailed stages, in sequence. This methodology was followed by several foreign countries for their geological disposal programs. General properties related to geological environments were obtained at the preliminary site characterization stage; more detailed site characteristics were investigated during the detailed site characterization stage. The results of investigation of geology, hydro-geology, geochemistry, rock mechanics, solute transport and thermal properties at a site have to be combined and constructed in the form of a site descriptive model. Based on this site descriptive model, the site characteristics can be evaluated to assess suitability of site for radioactive waste disposal. According to foreign site characterization cases, 7 or 8 years are expected to be needed for site characterization; however, the time required may increase if the no proper national strategy is provided.

  • https://doi.org/10.7733/jnfcwt.2017.15.3.239 인용 PDF KSCI

Reproducibility of Lateral Cephalometric Landmarks According to Radiographic Image Enhancement (방사선상 enhancement 정도에 따른 측모두부방사선규격사진 계측점 설정의 재현도)

  • Ryu, Hwang-Sog;Hwang, Hyeon-Shik
    • The korean journal of orthodontics
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    • v.32 no.1 s.90
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    • pp.59-69
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    • 2002

  • The purpose of this study was to evaluate the reproducibility of lateral cephalometric landmarks according to radiographic image enhancement, and to contribute to the identification of cephalometric landmarks. Lateral cephalograms of ten individuals were taken and stored into computer. The images were then enhanced up to four grades by Quick Ceph Image Pro$^{TM}$ on condition that the gray-scale equalization number was 50 and the detail enhancement number was 50. After thirty two landmarks were identified on monitor images by five observers, the deviations from the mean, the distances estimated between identified points and the mean point of five identified points, were evaluated for each landmark at each enhancement grade. Through the statistical analysis, following results were obtained. 1. In case of unenhanced radiographic images, the inter-observer reproducibility of the landmarks showed a large variation. 2. The comparison of deviation from the mean according to the degree of radiographic image enhancement for each landmark showed that the inter-observer reproducibility was significantly different at 5 landmarks. 3. The landmark of pterygomaxillary fissure showed higher reproducibility at enhancement grade 1 and 2 images than at unenhanced images. So did the landmark of posterior nasal spine at enhancement grade 1 images, and the landmark of menton at enhancement grade 2, 3 and 4 images respectively. The above results suggest that the reproducibility of some landmarks can be increased by radiographic image enhancement during the identification of the lateral cephalometric landmarks on the monitor.

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