• Nuclear Engineering and Technology
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• 제15권4호
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• pp.219-228
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• 1983

릴리프 밸브의 차단까지 TMI-2 사고의 blowdown history를 검토하고 TMI-2 사고와 같은 소규모의 냉각제 상실 사고 동안 노심 파괴를 막기 위해 더 가산해야할 측정 기구에 대하여 논의하였다. 가산된 기구를 이용하여 어떻게 노심의 uncovered level과 operator time margin을 계산하는 가를 검토하였으며, TMI-2 사고에 대해 uncovered level과 operator time margin을 결정하기 위한 샘플 계산을 수행하였다. 이 방법을 이용해서 측정되는 변수들의 함수로써 uncovered level과 operator time margin을 보여주는 도표를 작성하였다.

• 한국압력기기공학회 논문집
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• 제4권2호
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• pp.13-19
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• 2008

In order to predict a remaining life of a plant, it is necessary to select the components that are critical to the plant life. The remaining life of those components shall be evaluated by considering the aging effect of materials used as well as numerous factors. However, when evaluating reliability of nuclear structural components, some problems are quite formidable because of lack of information such as operating history, material property change and uncertainty in damage models. Accordingly, if structural integrity and safety are evaluated by the deterministic fracture mechanics approach, it is expected that the results obtained are too conservative to perform a rational evaluation of plant life. The probabilistic fracture mechanics approaches are regarded as appropriate methods to rationally evaluate the plant life since they can consider various uncertainties such as sizes and shapes of cracks and degradation of material strength due to the aging effects. The objective of this study is to evaluate the structural integrity for a reactor pressure vessel under the small break loss of coolant accident by applying the deterministic and probabilistic fracture mechanics. The deterministic fracture mechanics analysis was performed using the three dimensional finite element model. The probabilistic integrity analysis was based on the Monte Carlo simulation. The selected random variables are the neutron fluence on the vessel inside surface, the content of copper, nickel, and phosphorus in the reactor pressure vessel material, and initial RTNDT.