Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT) (방사성폐기물학회지)

Korean Radioactive Waste Society (한국방사성폐기물학회)
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Establishment and Application of Nuclear Criticality Safety Validation Methodology

핵임계 안전성 검증 방법론 정립 및 적용

  • Lee, Seo Jeong (Korea Hydro & Nuclear Power Co., Central Research Institute) ;
  • Cha, Kyoon Ho (Korea Hydro & Nuclear Power Co., Central Research Institute)
  • 이서정 (한국수력원자력(주) 중앙연구원) ;
  • 차균호 (한국수력원자력(주) 중앙연구원)
  • Received : 2018.01.26
  • Accepted : 2018.07.04
  • Published : 2018.09.30
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Abstract

A subcritical facility must ensure nuclear criticality safety under all circumstances. For this purpose, it is essential to have a procedure to validate that calculated values do not exceed upper subcritical limit (USL), determined by quantifying the bias and uncertainty. However, there are several validation methodologies of nuclear criticality safety and these can yield different USL. Therefore, it is necessary to analyze the validity of the methodologies to establish one methodology that can provide the most appropriate USL. In this study, two documents, a guide for validation of nuclear criticality safety calculational methodology (NUREG/CR-6698) and a criticality benchmark guide for light water reactor fuel in transport and storage package (NUREG/CR-6361), are compared and analyzed. In particular, the methodology in NUREG/CR-6361 is applied to the USLSTATS code. However, the analysis results show that the methodology in NUREG/CR-6698 is more appropriate, for several reasons. This is applied to decision of USL to design casks using SCALE code version 6.1.

미임계 시설은 정상 또는 사고상태에서 핵임계안전성이 확보되어야 한다. 이를 위해선 계산된 임계도가 바이어스와 불확실도로 결정된 미임계상한치(USL)를 초과하지 않는다는 것을 검증하는 절차가 반드시 필요하다. 하지만 핵임계안전성 검증방법론은 여러 가지가 존재하며, 방법론이 달라지면 USL도 달라지므로 가장 적절한 한가지의 방법론으로 평가하는 것이 중요하다. 본 연구에서는 핵임계안전성 검증 방법론이 기술된 두 개의 문서를 비교 분석하여 한 가지 방법론으로 정립하였고, SCALE6.1 코드를 이용한 용기 설계에서의 미임계상한치 결정에 적용하였다.

Keywords

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