Journal of the Korean Society for Nondestructive Testing (비파괴검사학회지)

The Korean Society for Nondestructive Testing (한국비파괴검사학회)
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Development of Automated Nondestructive Inspection System for BMI Nozzles in Nuclear Vessel

원자로 BMI 노즐 검사를 위한 자동화 비파괴검사 시스템 개발

  • Park, Joon Soo (R&D Institute, Doosan Heavy Industries and Construction Co., Ltd.) ;
  • Lee, Won Kun (R&D Institute, Doosan Heavy Industries and Construction Co., Ltd.) ;
  • Han, Won Jin (R&D Institute, Doosan Heavy Industries and Construction Co., Ltd.) ;
  • Lee, Sun Ho (R&D Institute, Doosan Heavy Industries and Construction Co., Ltd.) ;
  • Seong, Un Hak (R&D Institute, Doosan Heavy Industries and Construction Co., Ltd.)
  • 박준수 (두산중공업(주) 기술연구소) ;
  • 이원근 (두산중공업(주) 기술연구소) ;
  • 한원진 (두산중공업(주) 기술연구소) ;
  • 이선호 (두산중공업(주) 기술연구소) ;
  • 성운학 (두산중공업(주) 기술연구소)
  • Received : 2013.01.02
  • Accepted : 2013.02.07
  • Published : 2013.02.28
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Abstract

BMI nozzles in bottom head of the nuclear vessel are one of major components in nuclear power plants. The BMI nozzles have high possibility to generate PWSCC(primary water stress corrosion crack) according to recent foreign case although operation temperature is lower then the upper head of the nuclear vessel. Thus, nondestructive inspection of the BMI nozzles is required. But, inspection of BMI nozzles is not easy since the BMI nozzles placed in high radiated area and inside the nozzles filled with boric acid. Thus, in this study, a TOFD transducer for inspection of BMI and automated scanner system with water were developed. Also, validation of performance of the developed transducer and system are performed using specimens with artificial defects.

원자로 BMI 노즐은 원자력발전 설비의 운영을 위한 핵심요소 중 하나이며 하부헤드에 설치되어 있다. 상부헤드에 비해 비교적 저온영역에 있지만 최근 외국사례에 비추어 볼 때 PWSCC의 발생 가능성이 크기 때문에 가동중 비파괴검사가 반드시 필요하다. 그러나 BMI 노즐은 원자로 하부에 있기 때문에 고방사선 구역이며 원자로 내부는 붕산수로 채워져 있기 때문에 접근이 매우 어렵다. 본 연구에서 BMI 노즐 검사를 위하여 TOFD를 이용한 탐촉자를 개발하였고, 자동화검사를 위해 내방수 기능을 가진 스캐너를 개발하였다. 또한, BMI 노즐과 동일한 재질 및 형상으로 인공결함시험편을 제작하여 자동화 비파괴검사 시스템의 성능검증을 수행하였다.

Keywords

References

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