• Nuclear Engineering and Technology
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• 제32권1호
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• pp.57-66
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• 2000

The RELAP5 code has been developed for best-estimate simulation of transients and accidents for pressurized water reactors and their associated systems, but it has not been fully assessed for those of CANDU reactors. However, a previous study suggested that the RELAP5 code could be applicable to simulate the transients and accidents for CANDU reactors. Nevertheless, it is indicated that there are some works to be resolved, such as modeling of headers and multi-channel simulation for the reactor core, etc. Therefore, this study has been initiated with an aim to identify the code applicability for all the postulated transients and accidents in CANDU reactors. In the present study, the small inlet header break experiment (B8604) in the RD-14 test facility was simulated with RELAP5/MOD3.2 code. The RELAP5 results were also compared with both experimental data and those of CATHENA analyses performed by AECL and the analyses demonstrated the code's capability to predict major . phenomena occurring in the transient with sufficient accuracy for both Qualitative and quantitative viewpoint However, some discrepancies in the depressurization of the primary heat transport system after the break and the consequent time delay of the major phenomena were also observed.

• 한국조명전기설비학회지:조명전기설비
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• 제11권4호
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• pp.92-99
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• 1997

본 논문에서는 공동주택의 승강기 설비에서 경보 처리 방법을 신경회로망을 적용하여 감시제어의 효율을 향상시킬 수 있는 방안을 제시하였다. 제안된 방법은 역전파 알고리즘의 누가 역전파 알고리즘을 이용하여 다중 경보 발생에서 최소 경보요소를 추론하는데 사용하고 추론된 경보는 사전에 정의된 고장진단 지식베이스를 이용하여 설비 유지보수 정보를 화면에 전개하도록 구성하였다. 제안된 감시기법의 유용성을 확인하기 위하여 3가지의 가상시나리오를 통해서 신경회로망의 적용 가능성을 확인할 수 있었으며 공동주택에 적용한다면 유지보수 환경에 활용할 수 있을 것이다.

• 에너지공학
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• 제23권4호
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• pp.112-122
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• 2014

A main steam line break (MSLB) test at the ATLAS facility was simulated using the best-estimate thermal-hydraulic system code, MARS-KS. This has been performed as an activity at the third domestic standard problem for code benchmark (DSP-03) that has been organized by Korea Atomic Energy Research Institute (KAERI). The results of the MSLB experiment and the MARS input data prepared for the previous DSP-02 using the ATLAS facility were provided to participants. The preliminary MSLB simulation using the base input data, however, showed unphysical results in the primary-to-secondary heat transfer. To resolve the problems, some improvements were implemented in the MARS input modelling. These include the use of fine meshes for the bottom region of the steam generator secondary side and proper thermal-hydraulics calculation options. Other input model improvements in the heat loss and the flow restrictor models were also made and the results were investigated in detail. From the results of simulations, the limitations and further improvement areas of the MARS code were identified.

• 한국해양공학회지
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• 제27권6호
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• pp.7-15
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• 2013

Eco-friendly and sustainable seaweed biomass energy have been under the spotlight as the future of renewable energy. However, seaweed culture is primarily conducted inshore, with the research on offshore culture still in an early stage. For massive biomass production, a systematic engineering approach is required to devise offshore seaweed culture facilities rather than the conventional empirical ones. To establish the fundamental behavior of seaweed culture facilities, the dynamic characteristics of a seaweed culture facility were analyzed in the study. For this purpose, numerical analyses of the seaweed culture facility (a frame type) were carried out by using the hydrodynamic simulation program ANSYS-AQWA. For the analysis, environmental loads were considered using the wave spectra and co-linear current; mooring variables were selected as parameters; and time domain analyses were carried out to acquire the time series responses and eventually the dynamic characteristics. Finally, the mooring performance was evaluated. It was found that the motion could be controlled by adjusting the buoyancy and mooring slope.

• 대한산업공학회지
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• 제20권2호
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• pp.65-76
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• 1994

The most effective computer algorithms for facility layout that have been found are mainly based on the improvement heuristic such as CRAFT. In this paper, we present a new algorithm which is based on the Kohonen neual network. The algorithm firstly forms a self-organizing feature map where the most important similarity relationships among the facilities are converted into their spatial relationships. A layout is then obtained by a minor adjustment to the map. Some simulation results are given to show the performance of the algorithm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.955-957
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• 1998

This paper presents an adaptive reclosing scheme to improve the reliability in power distribution systems. For an originated faults, this scheme can determine the number of reclosing attempts, so that minimizes the affect of electric facility and customers' load. To verify the effectiveness of the proposed scheme. numerical simulation which calculates a various indices to consider the reliability and the effect of electric facility, is carried out with actual field data. Results show that the proposed scheme can be applicable to field operation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.896-898
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• 1996

This paper presents the optimal operation scheduling of the private cogeneration system connected with auxiliary equipments. And the optimal size of auxiliary equipments is determined through evaluations of the minimum operation cost. The optimal operation scheduling is established by using the linear programming method. Simulation results show that the auxiliary boiler is operated as an economical facility but the thermal storage tank is used as a back up facility for emergency.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제37회 추계학술대회논문집
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• pp.835-840
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• 2011

한국형발사체에서 독자적인 액체로켓엔진을 확보하기 위해 터보펌프개발은 필수적인 항목이라고 볼 수 있으며, 이 터보펌프의 실험적 신뢰성검증을 위한 실매질 시험설비의 구축을 위해 최근 액체산소와 케로신을 토대로 한 시험설비의 상세설계가 수행되어져 왔다. 본 논문에서는 시험설비 설계결과를 토대로 75톤급 터보펌프의 요구규격과 함께 실매질 시험설비의 설계규격을 제시하였고, 대표적인 서브시스템들의 설계결과를 설명하였다. 또한, 시험설비 운용과정에서 발생할 수 있는 주요 서브시스템에 대한 불확실성을 시뮬레이션과 실험적 검증을 통하여 사전에 제거할 수 있도록 하였다.

• Nuclear Engineering and Technology
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• 제51권8호
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• pp.1951-1956
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• 2019

As a part of the preliminary decommissioning plan of KEPCO-NF fuel fabrication facility, DCGLs of three target radionuclides, ²³⁴U, ²³⁵U, and ²³⁸U, were derived using RESRAD-BUILD code and contaminated areas of the facility were classified based on contamination levels from the derived DCGLs. From code simulations, one-room modeling results showed that the grinding room in building #2 was the most restrictive (DCGL_gross = 10493.01 Bq/㎡). The DCGL_gross results in contaminated areas from one-room modeling were slightly more conservative than three-room modeling. Prior to the code simulation, field survey and measurements conducted by each survey unit. For a conservative approach, the most restrictive DCGL_gross in each survey unit was taken as a reference to classify the contaminated areas of the facility. Accordingly, seven rooms and 37 rooms in the nuclear-fuel buildings were classified as Class 1 and Class 2, respectively. As expected, fuel material handling and processing rooms such as the grinding room, sintering room, compressing room, and powder collecting room were included in the Class 1 area.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제31회 추계학술대회논문집
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• pp.411-415
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• 2008

이 논문은 고도모사 시험설비의 전체 사양을 결정에 관계되는 엔진 입구에서의 고도비행 경험을 위한 모의대기 요구 조건, 모의 비행중 쇼요되는 연료 소모량 및 공급 방법, 시험모드별 냉각부하 예측, 효과적인 압력 회복률을 위한 배기 이젝터의 최적형상 결정에 관한 고려사항을 기술하였다. 이를 위하여 엔진의 연료소모량을 고려한 엔진 배기가스의 온도 및 배출량 등의 계산을 수행되었다.