• Title/Summary/Keyword: 원전 구조물

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A Study of Time Dependent Diffusion for Prediction Service Life in NPPs Safety Related Concrete Structures (원전 안전관련 콘크리트 구조물의 수명예측을 위한 재령계수에 대한 연구)

  • Lee, Choon-Min;Yoon, Eui-Sik;Kim, Seung-Soo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.3
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    • pp.136-142
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    • 2019
  • Nuclear power plant concrete structures are in contact with the coast, and durability due to chloride attack is very important because it is used as cooling water by taking seawater. For this purpose, a 3-year long-term saltwater immersion test was carried out to evaluate chloride ion diffusion coefficient and age apponent (m) The m values of the foundation with 4,000 class was 0.35 ~ 0.39, similar to KCI or ACI suggested values. essential service water constructions and tunnels of 5,000 class were 0.44 ~ 0.53 and 6,000 class, and 0.62 of reactor containment buildings were similar to the proposed values of FIB. As a result of the prediction of the service life with the measured age coefficient, all the safety related concrete structures of the nuclear power plants satisfied the service life of more than 60 years.

The Effects of Impurity Composition and Concentration in Reactor Structure Material on Neutron Activation Inventory in Pressurized Water Reactor (경수로 구조재 내 불순물 조성 및 함량이 중성자 방사화 핵종 재고량에 미치는 영향 분석)

  • Cha, Gil Yong;Kim, Soon Young;Lee, Jae Min;Kim, Yong Soo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.14 no.2
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    • pp.91-100
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    • 2016
  • The neutron activation inventories in reactor vessel and its internals, and bio-shield of a PWR nuclear power plant were calculated to evaluate the effect of impurity elements contained in the structural materials on the activation inventory. Carbon steel is, in this work, used as the reactor vessel material, stainless steel as the reactor vessel internals, and ordinary concrete as the bio-shield. For stainless steel and carbon steel, one kind of impurity concentration was employed, and for ordinary concrete five kinds were employed in this study using MCNP5 and FISPACT for the calculation of neutron flux and activation inventory, respectively. As the results, specific activities for the cases with impurity elements were calculated to be more than twice than those for the cases without impurity elements in stainless and carbon steel. Especially, the specific activity for the concrete material with impurity elements was calculated to be 30 times higher than that without impurity. Neutron induced reactions and activation inventories in each material were also investigated, and it is noted that major radioactive nuclide in steel material is Co-60 from cobalt impurity element, and, in concrete material, Co-60 and Eu-152 from cobalt and europium impurity elements, respectively. The results of this study can be used for nuclear decommissioning plan during activation inventory assessment and regulation, and it is expected to be used as a reference in the design phase of nuclear power plant, considering the decommissioning of nuclear power plants or nuclear facilities.

Study for Semi-Quantitative Analysis Method for Micro-Structure by Xrd in Concrete for Nuclear Power Plant (XRD 분석기법을 이용한 원전콘크리트 미세구조의 상대적 정량화에 대한 연구)

  • Kim, Do-Gyeum;Ann, Ki-Yong;Kim, Jae-Hwan
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2010.04a
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    • pp.770-772
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    • 2010
  • 기존의 연구는 열화에 의한 물리적 평가 및 열화에 영향을 미치는 수화생성물의 존재여부에 대한 연구는 활발하게 이루어지고 있으나, 그에 따른 수화생성물의 정량화에 대한 연구는 미흡한 실정이다. 본 논문은 XRD 분석 기법을 이용하여 원전 콘크리트 구조물에 대해 열화요인 중 탄산화와 황산염에 대한 상대적 정량화에 대한 연구를 실시하였다. 두 열화인자는 콘크리트 내의 수산화칼슘과 반응하여 에트린가이트와 탄산칼슘을 생성하게 되는데, 본 연구에서 열화인자에 대한 노출기간이 증가할수록 열화에 영향을 미치는 수화 생성물이 증가하는 것을 확인 할 수 있었다. 그에 따른 수산화칼슘의 양이 감소하는 것도 확인 할 수 있었다.

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