• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1997.10a
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• pp.90-97
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• 1997

The purpose of this study is to evaluate the seismic response characteristics of Wolsong nuclear power plant (NPP) structures for the Kyeongju earthquake(ML=4.3) occurred on June 26, 1997. The seismograms are obtained from five accelerographs of nuclear power plant at Wolsong, Kyeongbuk. The distance from the epicenter is about 25km. The peak acceleration (PA) due to the earthquake is 0.0235g, which is far lower value than that of design basis earthquake(DBE). The PA at the containment wall is about twice as large as that at free field. Also, the higher the accelerograph is located in, the larger the PA is measured to be From the response spectrum analysis, the dominant frequency of the response is close to 4 Hz, which is similar to the free field is poor because of contamination by high frequency waves as a result of reflection and diffraction between ground and NPP structure. We are of opinion that the accelerograph at the free field should be moved approximately twice the building dimension away from the containment structure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.9-10
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• 2015

Generally significant reinforcement is used in nuclear power plant structures and may cause potential problems when concrete is poured. In particular pouring concrete into structural member joint area is more difficult than other areas since the joint area is very congested due to the crossed bars and the embedded plates, The purpose of this study is to solve these problems by applying Gr.80(550MPa) shear bars to containment structures of nuclear power plant. In order to apply them to containment structures, it is necessary to change ASME-CC code (ASME Sec.III Div.2). The structural performance tests of wall & beam have been done to compare Gr.80(550Mpa) with Gr.60(420MPa) shear bars. The test results and code change proposal were presented to ASME-CC Committee last year and the discussion for code change will be expected to proceed in the near future.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.577-584
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• 2003

Tension tests of half-thickness concrete containment wall elements and material tests were conducted to derive a crack pattern and constitutive law of concrete. Main test variables are reinforcement ratio and the applied load ratio in two direction, and its effect on the behavior of reinforced concrete panel subjected to biaxial tension is investigated. Based on the test results, analytical expression is derived for the stress-strain relationship of concrete in tension. Ultimate analyses of reinforced concrete panels are carried out by a general purpose structural analysis computer program(ABAQUS), and its results are compared with the test results. The present analysis focuses on the effects of pre-analysis prior to test of specimens. These ultimate tensile analyses as pre-analysis are essential and important to design an effectual scheme of test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.587-595
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• 2018

Countries that have been banned from building nuclear plants are becoming more tolerant in response to global warming and climate change. Thus, the construction of future nuclear plants will increase, and the competition will also intensify. A nuclear power plant has a long construction period compared with conventional construction projects. In order to gain a competitive advantage in nuclear power plant construction, the construction period must be decreased. Therefore, the purpose of this study is to develop an exterior wall form for a reactor containment building to reduce the construction time by increasing the height of the form. The structural safety, constructability, and economic feasibility were analyzed to assess the applicability of the proposed form. The proposed form was determined to be structurally safe. Furthermore, the construction period was shortened by reducing the duration of the construction units, and the total construction cost and interest were also reduced. Therefore, the proposed form could contribute to reducing the construction period for nuclear power plants.

• Journal of the Korean Institute of Gas
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• v.18 no.1
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• pp.17-24
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• 2014

LNG storage tank is a facility to store liquefied natural gas (LNG) and its safety and stability to be greatly needed. When there is a LNG leakage in case of primary container problem, a special facility such as a bund wall should be constructed to store the leaked LNG. But this method makes the land usage inefficient and construction price high. So nowadays the full containment type LNG storage tank is selected instead of constructing a bund wall. In the full containment type tank, the concrete sidewall has the ability to store LNG temporarily. There are largely two methods to give the concrete sidewall the ability. In a method, rebar should be used when constructing the side wall of the LNG storage tank. In the other method, the protecting material such as sprayed polyurethane foam should be applied on the inner surface of the concrete sidewall. Sprayed PUF keeps the temperature of the sidewall above the specified temperature during the specified periods. Recently the thermal stability reinforcing method using sprayed polyurethane foam has been applied to all LNG storage tank built in Korea.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.18-24
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• 2008

This paper presents the stress and deformation behaviors of 9% nickel steel inner tank in a full containment LNG storage tank using a FE analysis. For an increased strength safety of an inner tank, the tension cable was fastened around the outside wall of an inner tank, which is known as a weak zone for the hydrostatic pressures, cryogenic temperature loads, and other loadings. Based on the FEM computed results between a conventional inner tank and a inner tank with tension cables around the lower part of the side wall of an inner tank, the redesigned inner tank is more safe than that of the conventional tank without a tension cable. The FEM results recommend $3{\sim}4$ steel tension cables with a diameter of 50mm for an increased strength safety of the inner tank, which may decrease the stress concentration and deformation near the lower part of the side wall. Thus the tension cable around the inner tank may be used as an alternative safety device compared to the stiffener and the top girder structures for the increased LNG storage tank, especially.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.325-330
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• 2000

In general steel sheet pile use the containment system, vertical barrier systems for waste disposal and landfill purposes, roads in excavation which have a more permanent character or temporary structure. The sheet pile joints between section of the wall are sealed with a filter material arid the resistance to seepage is a function of the type of material employed. The aim of this paper is to review a characteristic of permeability for Z type sheet pile by field test in various condition.

• Geotechnical Engineering
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• v.13 no.2
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• pp.9-16
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• 1997

Cut-off methods of controlling leachate migration from waste landfills and contaminated sites are studied. Permeability and chemical compatibility tests are prrforlned on slurry wall materials including soil-bentonite, cement-bentonite, cement / fly ash-bentonite, plastic concrete. Hydraulic conductivity of soil-bentonite mixture is the lowest of these four bacuill materials. The leachate from municipal solid waste has little influence on the permeability of the backfill materials. The bentonite slurry becomes flocculated and aggregated when exposed to the leachate. The results of the permeability test showed that the hydraulic conductivities of the backfill materials are in the order soil-beiltonite, Plastic concrete, cement-bentonite. And the result c: the compatibility test showed increase in permeability due to the effects of leachate. Thus, in designing the slurry wall it is essential to check the behaviour of the bentonite slurry and backfill materials on the compatibility with the contaminants.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.193-194
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• 2012

Construction work is affected by the weather; e.g. snowfall, rainfall and low-high ambient temperature, especially at a site in a severe climate. The influence of the weather is one of the possible reasons for delays in a construction schedule and quality deterioration. To protect the worksite from severe weather conditions, the temporary roof and wall could be installed on the outside of main structures designed in advance and the temporary structures could be took down after a period use. The greater coverage all-weather construction method is applied, the larger the effect. so, it is important and needs that the temporary roof and wall can be widely applied, designed to effectively about structure and layout.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.403-414
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• 1994

Nonlinear analysis of RC containment structure under thermal load and pressure is presented to trace the behaviour after an assumed LOCA. The temperature distribution varying with time through the wall thickness is determined by transient finite element analysis with the two time level scheme in time domain. The layered shell finite elements are used to represent the containment structures in nuclear power plants. Both geometric and material nonlinearities are taken into account in the finite element formulation. The constitutive relation of concrete is modeled according to Drucker-Prager yield criteria in compression. Tension stiffening model is used to represent the tensile behaviour of concrete including bond effect. The reinforcing bars are modeled by smeared layer at the location of reinforcements accounting elasto-plastic axial behaviors. The steel liner model under Von Mises yield criteria is adopted to represent elastic-perfect plastic behaviour. Geometric nonlinearity is formulated to consider the large displacement effect. Thermal stress components are determined by the initial strain concept during each time step. The temperature differential between any two consecutive time steps is considered as a load incremental. The numerical results from this study reveal that nonlinear temperature gradient based on transient thermal analysis will produces excessive large displacement. Nonlinear behavior of containment structures up to ultimate stage can be traced reallistically. The present study allows more realistic analysis of concrete containment structures in nuclear power plants.