Journal of Korean Society of Occupational and Environmental Hygiene (한국산업보건학회지)

Korean Industrial Hygiene Association (한국산업보건학회)
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Analysis of Local Exposure Levels of Radiation Emitted from Soft X-ray Ionizers in LCD Manufacturing Processes

LCD 제조공정의 이온화 장치에 대한 전리방사선 지역노출특성 분석

  • Kim, JoonBeom (Occupational Safety and Health Research Institute, KOSHA) ;
  • Chung, Eun-Kyo (Occupational Safety and Health Research Institute, KOSHA) ;
  • Jung, Kihyo (Department of Safety and Health, University of Ulsan)
  • 김준범 (한국산업안전보건공단 산업안전보건연구원) ;
  • 정은교 (한국산업안전보건공단 산업안전보건연구원) ;
  • 정기효 (울산대학교 안전보건전문학과)
  • Received : 2021.08.05
  • Accepted : 2021.11.07
  • Published : 2021.12.30
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Abstract

Objectives: This study analyzed the local exposure levels of radiation emitted from the equipment with soft X-ray ionizers to investigate the radiation exposure levels in Liquid Crystal Display(LCD) manufacturing processes. Methods: This study measured the local radiation levels for the equipment installed in two LCD manufacturing companies. The equipment were installed at diverse processes and equipped with various number of ionizers. The local radiation levels were measured on the surface of the equipment by using direct reading equipment, and the measurements were converted into annual effective dose by considering the radiation exposure time of workers. Statistical analyses were performed to investigate the radiation exposure characteristics. Results: Annual effective doses for 97.6% of the equipment being measured were less than 1 mSv. However, the range of annual effective doses was 0.004 mSv ~ 2.167 mSv, which indicated a large variation among the equipment. Statistical analyses of the study found that this large variation was raised due to improper shielding of the equipment rather than process and/or equipment characteristics. To pinpoint the cause of this large variation in annual effective dose, this study improved the shielding of the equipment being radiated over 1 mSv and found that their average effective dose was reduced from 1.604 mSv to 0.126 mSv after shielding improvement. Conclusions: Relatively high exposure levels of radiation were observed in some equipment where their shielding were insufficiently thick and/or sealed. This finding implies that the shielding of the equipment is an important engineering countermeasure to control the radiation exposure levels in industries.

Keywords

Acknowledgement

본 연구는 산업안전보건연구원의 자체연구과제로 수행한 결과입니다.

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