• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1239-1241
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• 1999

In this paper, we propose real time transient stability assessment and energy margin estimation using fuzzy approximate reasoning. The proposed method used rotor angle, kinetic energy and acceleration power of generators at clearing time as fuzzy input. In order to calculate energy margin in transient energy function (TEF), we obtained controlling unstable equilibrium point (UEP) using mode of disturbance procedure (MOD). The proposed algorithm is tested on 4-machine, 6-bus, 7-line power system to prove of effectiveness.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.659-664
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• 1998

The importance of input wariables of real-time accident consequence assessment model has been analyzed. Partial correlation coefficients of input variables related to the plume and the ingestion exposure have been estimated using latino hypercube sampling technique. It is known that wind speed and growth dilution rate are the most important variable in plume and ingestion exposure, respectively.

• Journal of Environmental Impact Assessment
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• v.3 no.2
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• pp.15-24
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• 1994

The goal of impact studies (e.g., as mandated by NEPA in the USA) is to ensure that the full implications of development proposals (ecologic, economic, and social) are taken into account before decisions are made and projects are allowed to proceed. In other words, the aim is to ensure that impact assessment is integrated into planning and policy processes. Today. nearly 25 years after the enactment of NEPA, it is appropriate to inquire regarding the extent of progress toward such integration. This paper examines the role of impact assessment in planning and policy processes with specific reference to resource development projects in the Great Plains region of the USA. The author gives special attention to the socioeconomic impacts associated with energy resource extraction and conversion projects and the role of impact assessment in project evaluation, in local and regional planning, and in state policy development.

• KIEAE Journal
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• v.15 no.6
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• pp.87-92
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• 2015

Purpose: The green building certification system in Korea was introduced in 2002 and developed as an improvement version of the G-SEED(Green Standard for Energy and Environmental Design) system in 2013. This study conducts surveys targeting architectural designers and users on significance of certification assessment criteria for apartment buildings on the G-SEED system and examines the differential views between the two groups on assessment criteria. Method: First, The AHP(Analytic Hierarchy Process) method was used to find importance of assessment criteria and then the importances were compared with weighted points on the certification standard. Second, the t-test was used to investigate differential views between designer and user groups on certification assessment criteria based on drawn importances. Result: (1) While designer group considered land use and transportation, energy and environmental pollution, and water circulation management as more important, user group did material and resource, maintenance management, ecological environment, and indoor environment as more important. (2) Based on t-test results, sustainable energy, water circulation system, site management, habitat, acoustical environment, and light environment were found to be different on importance between the two groups.

• Journal of Environmental Impact Assessment
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• v.22 no.6
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• pp.639-648
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• 2013

Unconventional natural gas resources are now estimated to be as large as conventional resources. Unconventional natural gas has became an increasingly important source of energy in the world since the start of this century. The factors that drive natural gas demand and supply point more and more to a future in which natural gas plays greater role in the global energy mix. The expansion of using natural gas will be expected in Korea. This research aims to analyze environmental impacts of expansion of unconventional natural gas. This research was carried out for comparative analysis between global energy mix and Korea energy mix, and developed a case that reflect the changed energy mix due to the expansion of unconventional natural gas in Korea. Also this research evaluate the production of air pollutants and the cost of the damage in power generation sector. The results of this research can be summarized as that natural gas portion of future global energy mix (about 25%) is greater than Korea energy mix (about 12%). This research developed a case that replace 10% energy of power generation sector to natural gas in the 6th demand supply program, reflecting the changed energy mix due to the expansion of natural gas use. In that case, air pollutants would be reduced gradually through 2015 to 2027. In detail, carbon dioxide reduces 22 million tons and environmental damage cost reduces 4500 billion won by 2027.

• Nuclear Engineering and Technology
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• v.41 no.5
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• pp.747-752
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• 2009

A vulnerability assessment is essential for the efficient operation of a physical protection system (PPS). Previous assessment codes have used a simple model called an adversary sequence diagram. In this study, the use of a two-dimensional (2D) map of a facility as a model for a PPS is suggested as an alternative approach. The analysis of a 2D model, however, consumes a lot of time. Accordingly, a generalized heuristic algorithm has been applied to address this issue. The proposed assessment method was implemented to a computer code; Systematic Analysis of physical Protection Effectiveness (SAPE). This code was applied to a variety of facilities and evaluated for feasibility by applying it to various facilities. To help upgrade a PPS, a sensitivity analysis of all protection elements along a chosen path is proposed. SAPE will help to accurately and intuitively assess a PPS.

• Earthquakes and Structures
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• v.12 no.6
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• pp.653-663
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• 2017

A seismic margin assessment evaluates how much margin exists for the system under beyond design basis earthquake events. Specifically, the seismic margin for the entire system is evaluated by utilizing a systems analysis based on the sub-system and component seismic fragility data. Each seismic fragility curve is obtained by using empirical, experimental, and/or numerical simulation data. The systems analysis is generally performed by employing a fault tree analysis. However, the current practice has clear limitations in that it cannot deal with the uncertainties of basic components and accommodate the newly observed data. Therefore, in this paper, we present a Bayesian-based seismic margin assessment that is conducted using seismic fragility data and fault tree analysis including Bayesian inference. This proposed approach is first applied to the pooltype nuclear research reactor system for the quantitative evaluation of the seismic margin. The results show that the applied approach can allow updating by considering the newly available data/information at any level of the fault tree, and can identify critical scenarios modified due to new information. Also, given the seismic hazard information, this approach is further extended to the real-time risk evaluation. Thus, the proposed approach can finally be expected to solve the fundamental restrictions of the current method.

• Nuclear Engineering and Technology
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• v.50 no.8
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• pp.1217-1233
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• 2018

Following a surge of interest in multi-unit risk in the last few years, many recent studies have suggested methods for multi-unit probabilistic safety assessment (MUPSA) and addressed several related aspects. Most of the existing studies though focused on two-unit nuclear power plant (NPP) sites or used rather simplified probabilistic safety assessment (PSA) models to demonstrate the proposed approaches. When considering an NPP site with three or more units, some approaches are inapplicable or yield very conservative results. Since the number of such sites is increasing, there is a strong need to develop and validate practical approaches to the related MUPSA. This article provides several detailed approaches that are applicable to multi-unit Level 1 PSA for sites with up to six or more reactor units. To validate the approaches, a multi-unit Level 1 PSA model is developed and the site core damage frequency is estimated for each of four representative multi-unit initiators, as well as for the case of a simultaneous occurrence of independent single-unit initiators in multiple units. For this purpose, an NPP site with six identical OPR-1000 units is considered, with full-scale Level 1 PSA models for a specific OPR-1000 plant used as the base single-unit models.

• Journal of Radiation Protection and Research
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• v.28 no.3
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• pp.247-254
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• 2003

To prevent the potential health detriment to the public from radioactive effluents, radiological dose assessments due to the operation of nuclear facilities located at Korea Atomic Energy Research Institute (KAERI) site has been performed semiannually in compliance with the Minister of Science and Technology (MOST)'s Notice in Korea. Radiological dose assessment based on the new recommendation of the International Committee on Radiation Protection (ICRP-60) has been conducted since 1998. In this manuscript, a serial activities at KAERI site to meet the regulatory standards for routine releases of radioactive effluents are introduced and discussed including technical approaches. It is clear that each nuclear facility has been operated in compliance with regulatory standards. Furthermore, it is identified that the radiation induced health effects for residents around the site are neglectable.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1272-1273
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• 2011

A study on demonstration to development of simulator to assessment for loss saving of harmonic electric power energy. harmonic occurs to electric equipment like increase of terminal voltage, resonance phenomena occurrence and noise. To circulate of loss saving of harmonic electric power energy, we assessment electric power loss saving by harmonic and estimate loss saving of far-infrared radiation panel heating system.