• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.621-631
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• 2017

Many developing countries considering the introduction of nuclear power find that large-scale reactor plants in the range of 1,000 MWe to 1,600 MWe are not grid appropriate for their current circumstance. By contrast, small modular reactors are generally too small to make significant contributions toward rapidly growing electricity demand and to date have not been demonstrated. This paper proposes a radically simplified re-design for the nuclear steam cycle for a medium-sized reactor plant in the range of 600 MWe. Historically, balance of plant designs for units of this size have emphasized reliability and efficiency. It will be demonstrated here that advances over the past 50 years in component design, materials, and fabrication techniques allow both of these goals to be met with a less complex design. A disciplined approach to reduce component count will result in substantial benefits in the life cycle cost of the units. Specifically, fabrication, transportation, construction, operations, and maintenance costs and expenses can all see significant reductions. In addition, the design described here can also be expected to significantly reduce both construction duration and operational requirements for maintenance and inspections.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2924-2932
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• 2022

Motivated by learning from experience and exploiting existing knowledge in civil nuclear operations, we have developed in-house generic Probabilistic Safety Assessment (PSA) models for pressurized and boiling water reactors. The models are computationally light, handy, transparent, user-friendly, and easily adaptable to account for major plant-specific differences. They cover the common internal initiating events, frontline and support systems reliability and dependencies, human-factors, common-cause failures, and account for new factors typically overlooked in many PSAs. For quantification, the models use generic US reliability data, precursor analysis reports, the ETHZ Curated Nuclear Events Database, and experts' opinions. Moreover, uncertainties in the most influential basic events are addressed. The generated results show good agreement with assessments available in the literature with detailed PSAs. We envision the models as an unbiased framework to measure nuclear operational risk with the same "ruler", and hence support inter-plant risk comparisons that are usually not possible due to differences in plant-specific PSA assumptions and scopes. The models can be used for initial risk screening, order-of-magnitude precursor analysis, and other research/pedagogic applications especially when no plant-specific PSAs are available. Finally, we are using the generic models for large-scale precursor analysis that will generate big picture trends, lessons, and insights.

• Ocean and Polar Research
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• v.39 no.2
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• pp.125-148
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• 2017

This study analyzed the community structure of macrobenthic organisms in the subtidal area suffering under the influence of thermal discharge from the Uljin nuclear power plant during 2012-2013 and reviewed the temporal change in the faunal composition of the macrobenthic community using data from previous studies since the start of the plant operation in 1989. A total of 319 species were collected in 2012-2013, with a mean density of $3,330ind./m^2$ and a mean biomass of $131.96g/m^2$. These results were similar to those obtained in 2006-2007. The dominant species were not different from each other before and after the power plant operations began, but the faunal density near the power plant drainage port was significantly higher compared to those densities obtained from other stations. Spiophanes bombyx and Polydora sp., which is known as a pollution indicator species, was dominant only in the drainage port area. The study area consisted of two subregions with different macrobenthic communities depending on the water depth, which was similar to the results of the 2006-2007 survey. The macrobenthic community structures before and after the operation of the power plant in the coastal area were not changed, but there were seasonal differences in the long-term macrobenthic community structure which were strongly related to the thermal discharge from the power plant.

• Journal of Environmental Health Sciences
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• v.22 no.1
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• pp.45-50
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• 1996

The application of HACCP system, which was adopted by Codex Alimentarius Committee for the safe meat and poultry production, is one of the urgent task for competing in the world trade markets. But there have been no useful analytical studies to identify the causes of contamination in the poultry meat processing plants in Korea. This study was conducted to investigate the potential hazards during the operations by the microbiological examination for the poultry meat processing plant (20,000 birds capacity a day) located in Kangwon province. In spite of air contamination of work places, it may not directly affect the surface contamination of poultry meats. But the risk of Campylobacter jejuni/coli contamination was high. The number of total count was decreased about ten times, but remarkable changes of microbial contamination could not be recognized in each procedure during the operations. The washing water was already contaminated as much as $10^{3-6}CFU/ml$ in SPC before the operations. It means that to keep water tanks hygienic is a primary step to prevent the occurrences of microbial contamination. The overflow and recirculation of water in scalding, washing, and chilling was aslo an important factor for a hygienic control. Based on this study, the followings could be regarded as an important factors for hygenic control in the poultry slaughtering plants on a small scale. The temperature of water used for scalding should be constantly maintained on a required temperature, and the overflow rate of 1~1.5 liter per bird. The carcass surface and the body cavity should be washed thoroughly and the cross-contamination due to facilities, workers, and tools should be prevented. The chilling water sholud be maintained under 5$\circ$C of temperature with ice and overflow, and residual chlorine level of 50 ppm.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.3
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• pp.383-397
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• 2012

In this study, a System Dynamics (SD) simulation model for the efficient operations of an industrial water supply system was developed by investigating the feedback loop mechanisms involved in the operations of the system. The system was modeled so that as demand is determined the water supply quantity of intake pumping stations and dams are allocated. The main feedback loop showed that many variables such as the combinations of pump operation, unit electric power(kWh/$m^3$), unit electric power costs(won/$m^3$), water level of water way tunnel, suction pressure and discharge of pumping station, and tank and service reservoir water level had causal effects and produced results depending on their causal relationship. The configurations of the model included an intake pumping station model, water way tunnel model, pumping station model (including the tank and service reservoir water level control model), and unit electric power model. The model was verified using the data from the case study industrial water supply system that consisted of a water treatment plant, two pumping stations and four dams with an annual energy costs of 5 billion won. It was shown that the electric power costs could have been saved 7~26% during the past six years if the operations had been based on the findings of this study.

• Journal of Korean Institute of Industrial Engineers
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• v.11 no.1
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• pp.51-61
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• 1985

Major changes of the industrial engineering curricula in U.S.A. were analysed in three stages: 1938, 1958 and 1984. There are tendencies that the traditional plant operation oriented courses are combined and compressed to a few courses while the system oriented courses such as SA, OR, computer applications, man-machine systems are expanding. It will be necessary to organize a study group such as ASEE conducting further studies to meet our needs by upgrading the engineering curriculum for the coming 90's education.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.828-834
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• 1989

On-Line optimization of process units has heretofore been restricted to the individual equipment level using linear approximate models. The advent of the low cost, high speed micro-computer coupled with the speed and robustness of an equation based exact simulator is making real-time optimization of entire process units a reality. The resultant implications for a decision system applied to day-to-day operations, point to a significant change in the way process plants will be managed in the future.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.493-497
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• 1991

A problem of analysis and design of asymptotically reliable serial production systems, closed with respect to the number of carriers that transport parts between operations, is addressed. A case study of a paint shop operation at a modern automobile assembly plant is described. The results obtained indicate that optimization of the system with respect to the number of carriers available and the capacity of the feedback buffer leads to a substantial improvement in the production rate.

• Journal of Intelligence and Information Systems
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• v.2 no.2
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• pp.17-27
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• 1996

본 논문에서는 화력발전소 터빈의 안정적 운전을 지원하고 발전소의 불시정지를 예방하기 위하여 필요한 전문가시스템의 지식베이스 구축과 그래픽 인터페이스에 대한 proto-type을 개발하였다. 본 연구에서 개발한 전문가시스템은 화력 발전소 터빈 계통의 현재 상태로부터 대상 운전조작에 대한 운전방법을 지원하는 기능, 고장을 진단하는 기능 등을 제공한다. 지식베이스는 객체와 규칙의 혼성형태로 구성하였으며, 추론방법으로는 후향추론을 기본적으로 사용하고 현재 운전상황에 따른 고장진단을 위하여 전향 추론을 혼용함으로써 필요에 따라 최적추론을 유도하였다. 또한 지식베이스의 효율적 활용과 사용자의 손쉬운 접근을 위하여 그래픽 사용자 인터페이스를 구현하였다.

• Journal of Energy Engineering
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• v.15 no.1 s.45
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• pp.67-73
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• 2006

A calculation method on performance impact of the controllable operations parameter such as GT inlet filter ${\Delta}P$, compressor efficiency, and condenser pressure was devised to achieve best performance of combined cycle power plant with the on-line performance monitoring system. This method calculates the performance impact on the deviation between 'Expected' values and 'Actual' values. Controllable parameter targets are determined based on achievable performance given existing equipments and control conditions.