• 한국지반환경공학회 논문집
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• 제11권8호
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• pp.57-63
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• 2010

본 연구에서는 준설투기장의 설계를 위하여 실내시험으로 컬럼을 이용한 준설토 침강 자중압밀시험 및 상등수에 대한 부유물 농도시험을 수행하였으며, 현장조건과 배출수의 부유물 농도를 고려한 준설투기장을 설계 검토하였다. 준설투기장 폭과 목표 부유물 농도와의 관계 검토결과, 소요면적에서는 투기장 폭이 좁고 길이가 길수록 부유물 농도가 감소함을 알 수 있었다. 또한 준설투기가 진행됨에 따라 배출되는 상등수의 부유물 농도의 변화를 예측하기 위하여 침강허용깊이의 변화에 대한 영향도 고려되어야 하며, 이는 배출수의 목표 부유물 농도가 낮을수록 더욱 중요하다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1995년도 추계학술발표회논문집(1)
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• pp.358-363
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• 1995

A study on passive cooling systems for concrete containment of advanced pressurized water reactors has been performed. The proposed passive containment cooling system (PCCS) consist of (1) condenser units located inside containment, (2) a steam condensing pool outside containment at higher elevation, and (3) downcommer/riser piping systems which provide coolant flow paths. During an accident causing high containment pressure and temperature, the steam/air mixture in containment is condensed on the outer surface of condenser tubes transferring the heat to coolant flowing inside tubes. The coolant transfers the heat to the steam condensing pool via natural circulation due to density difference. This PCCS has the following characteristic: (1) applicable to concrete containment system, (2) no limitation in plant capacity expansion, (3) efficient steam condensing mechanism (dropwise or film condensation at the surface of condenser tube), and (4) utilization of a fully passive mechanism. A preliminary conceptual design work has been done based on steady-state assumptions to determine important design parameter including the elevation of components and required heat transfer area of the condenser tube. Assuming a decay power level of 2%, the required heat transfer area for 1,000MWe plant is assessed to be about 2,000 ㎡ (equivalent to 1,600 of 10 m-long, 4-cm-OD tubes) with the relative elevation difference of 38 m between the condenser and steam condensing pool and the riser diameter of 0.62 m.

• 한국분무공학회지
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• 제4권3호
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• pp.42-52
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• 1999

An effectiveness of thermal utilization of a dousing system in the 600 MW PHWR Nuclear Power Plant has been evaluated. The behavior and conditions of water droplet sprayed in a postulated accident conditions in containment configuration has been calculated. In this calculation, two pressure conditions with the consideration of obstruction area and containment wall effect has been established : one being the minimum containment pressure of 7 kPa(g) encountered for dousing shut off and the other being the containment design pressure 124 kPa(g). The results revealed that the effectiveness of the thermal utilization ranges from 93% to 97%. In the analysis on two cases without/with side wall effect in the containment building, the thermal utilization decreases with obstruction area from 89% to 85%, which satisfies the design criteria set for the containment pressure against the accident condition.

• Nuclear Engineering and Technology
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• 제49권5호
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• pp.941-952
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• 2017

Using the Generation of Thermal-Hydraulic Information for Containments (GOTHIC) code, thermal-hydraulic phenomena that occur inside the containment have been investigated, along with the preliminary design of the passive containment cooling system (PCCS) of an innovative pressurized water reactor (PWR). A GOTHIC containment model was constructed with reference to the design data of the Advanced Power Reactor 1400, and report related PCCS. The effects of the design parameters were evaluated for passive containment cooling tank (PCCT) geometry, PCCS heat exchanger (PCCX) location, and surface area. The analyzed results, obtained using the single PCCT, showed that repressurization and reheating phenomena had occurred. To resolve these problems, a coupled PCCT concept was suggested and was found to continually decrease the containment pressure and temperature without repressurization and reheating. If the installation level of the PCCX is higher than that of the PCCT, it may affect the PCCS performance. Additionally, it was confirmed that various means of increasing the external surface area of the PCCX, such as fins, could help improve the energy removal performance of the PCCS. To improve the PCCS design and investigate its performance, further studies are needed.

• 한국지반환경공학회 논문집
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• 제11권10호
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• pp.41-48
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• 2010

본 연구에서는 기존에 적용된 준설투기장 설계에서 준설투기장에서 배출되는 상등수의 부유물 농도 예측에 대한 적합성 평가를 위하여 실제 현장 준설 시 준설투기장 내에서 준설토의 입도분포 및 상등수의 부유물 농도 분포를 측정하여 설계 예측 값과 비교하였으며, 상등수의 유속과 부유물 농도와의 관계를 분석하였다. 평가 결과, 현장 측정값과 설계 예측값이 비교적 유사한 경향을 보였으나, 준설 초기 및 상등수 유속이 증가한 시점에서는 설계 예측값과 상이한 측정값을 보였다. 이는 기존에 적용된 준설투기장 설계법이 준설 기간에 따라 민감하게 변화하는 준설토의 침강 깊이 및 상등수의 유속 등을 반영하지 못하기 때문으로 판단된다. 또한 준설투기장에서 동시에 측정된 유속과 부유물 농도의 분포가 유사한 경향을 보이므로 상등수의 유속과 부유물 침전이 상당히 밀접한 관계가 있는 것으로 관측되었다. 따라서, 현장 준설투기장 상황 변화를 보다 정확히 예측하기 위하여 준설토 계면고, 침강깊이, 상등수 유속에 따라 변화하는 부유물 침전을 고려한 준설투기장 설계법이 필요하다고 사료된다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.81-85
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• 1998

In the present study, the design method of containment walls is proposed by utilizing an existing site. The selected remedy for the Source Area of Operable Unit 2 at Hill Air Force Base stipulated containment of the pure-phase trichloroethylene contamination. The in-place-mixed wall construction was selected because of the irregular topography, small area of the site, and the requirement to reach depths of greater than 90 feet below ground surface. Bench-scale compatibility studies were performed for the containment wall mix design on three commercial bentonite clays. The samples were subject to screening tests and long-term tests for evaluation of changed soil properties when exposed to the contaminated groundwater.

• Nuclear Engineering and Technology
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• 제56권2호
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• pp.485-497
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• 2024

Ring beam is the main anchorage zone of the tendons in the nuclear power prestressed concrete containment vessel (PCCV). Its safety is crucial and has a great influence on the overall performance of PCCV. In this paper, two half-scale ring beams were tested to investigate the mechanical performance of the anchorage zone in the PCCV under multidirectional pressure. The effect of working condition with different tension sequences was investigated. Additionally, a half axisymmetric plane model of the containment was established by the finite element simulation to further predict the experimental responses and propose the local reinforcement design in the anchorage zone of the ring beam. The results showed that the ultimate load of the specimens under both working conditions was greater than the nominal ultimate tensile force. The original reinforcement design could meet the bearing capacity requirements, but there was still room for optimization. The ring beam was generally under pressure in the anchorage area, while the splitting force appeared in the under-anchor area, and the spalling force appeared in the corner area of the tooth block, which could be targeted for local strengthening design.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 춘계학술발표논문집 2부
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• pp.949-952
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• 2010

The utilization of LPG(Liquefied Petroleum Gas) is increasing as an environmental-friendly fuel in all countries making green growth new paradigm, and use of gas is spread fast as motor fuels to decrease air pollution. Loss of lives by explosion and fire is happening every year as gas use increases, and gas accident in large scale storage property is causing serious problems socially. To minimize this problem, underground containment type storage tank is being presented as an alternative recently. In this study, to minimize explosion occurrence in underground containment type storage tank, the suitable storage tank is designed to consider explosion prevention that makes exposure surface area minimize in confined contents volume and flame to construct storage tank by the most suitable condition in the underground containment room. As a result of the design of storage tank having the most suitable condition by this research, underground containment space was minimized on diameter 3m, length 4.83m in 20 tons storage tank and its safety was improved as exposure surface area in flame decreased by 89.4%, compared with the existent storage tank.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1221-1229
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• 2022

In this work, the guided wave de-bonding area-detecting technique was studied for application to containment liner plates in nuclear power plant areas. To apply this technique, an appropriate Lamb wave mode, symmetric and longitudinal dominance, was verified by the frequency shifting technique. The S0 2.7 MHz mm Lamb wave mode was chosen to realize quantitative experimental results and their visualization. Results of the bulk wave, longitudinal wave mode, and comparison experiments indicate that the wave mode was able to distinguish between the de-bonded and bonded areas. Similar to the bulk wave cases, the bonded region could be distinguished from the de-bonded region using the Lamb wave approach. The Lamb wave technique results showed significant correlation to the de-bonding area. As the de-bonding area increased, the Lamb wave energy attenuation effect decreased, which was a prominent factor in the realization of quantitative tomographic visualization. The feasibility of tomographic visualization was studied via the application of Lamb waves. The reconstruction algorithm for the probabilistic inspection of damage (RAPID) technique was applied to the containment liner plate to verify and visualize the de-bonding condition. The results obtained using the tomography image indicated that the Lamb wave-based RAPID algorithm was capable of delineating debonding areas.

• 한국정밀공학회지
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• 제28권2호
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• pp.233-238
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• 2011

In piping design of nuclear power plant facilities, the load stress according to self-weight is important for design values in test run(shutdown and starting). But sometimes it needs more studies, such as seismic analysis of an earthquake of power plant area and fatigue life and stress of thermal expansion and anchor displacement in operating run. In this paper, seismic evaluations were performed to nuclear piping system of Shin-Kori NO. 3&4 being built in Pusan lately. Results of seismic analysis are evaluated on basis of KEPIC MN code. The structural integrity on RCB piping system was proved.