• Nuclear Engineering and Technology
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• 제50권3호
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• pp.319-326
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• 2018

Since the Fukushima Daiichi nuclear disaster, concern and worry about multiunit accidents have been increasing. Korea has a higher urgency to evaluate its site risk because its number of nuclear power plants (NPPs) and population density are higher than those in other countries. Since the 1980s, technical documents have been published on multiunit probabilistic safety assessment (PSA), but the Fukushima accident accelerated research on multiunit PSA. It is therefore necessary to summarize the present situation and draw implications for further research. This article reviews journal and conference papers on multiunit or site risk evaluation published between 2011 and 2016. The contents of the reviewed literature are classified as research status, initiators, and methodologies representing dependencies, and the insights and conclusions are consolidated. As of 2017, the regulatory authority and nuclear power utility have launched a full-scale project to assess multiunit risk in Korea. This article provides comprehensive reference materials on the necessary enabling technology for subsequent studies of multiunit or site risk assessment.

• Transactions of the Korean hydrogen and new energy society
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• 제31권5호
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• pp.459-466
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• 2020

As the hydrogen industry grows, expansion of infrastructure for hydrogen supply is required, but the safety of hydrogen facilities is concerned due to the recent accidents at the Gangneung hydrogen tank and the Norwegian hydrogen fueling station. In this study, the damage range and impact analysis on the on-site hydrogen fueling station was conducted using Hy-KoRAM. This is a domestically developed program that adds functions based on HyRAM. Through this risk assessment, it was evaluated whether the on-site hydrogen fueling station meets international standards and suggested ways to improve safety.

• Nuclear Engineering and Technology
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• 제50권8호
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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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.66-70
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• 2005

Noise prediction are required as part of an environmental impact assessment. Prediction method that is used to domestic environmental impact assessment of construction site and industrial site is not applied work operation rate, work position, moving noise source, inner traffic flow, work type and height of noise source etc. The BS5228 methodology is used mainly for assessment of proposed open industrial sites(mineral extraction, landfill etc.), and larger long-term construction sites(typically for major infrastructure projects). also, estimation which consider various effect factor is possible.

• Nuclear Engineering and Technology
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• 제44권5호
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• pp.459-470
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• 2012

From the PSA point of view, the Fukushima accident of Japan in 2011 reveals some issues to be re-considered and/or improved in the PSA such as the limited scope of the PSA, site risk, etc. KAERI (Korea Atomic Energy Research Institute) has performed researches on the development of an integrated risk assessment framework related to some issues arisen after the Fukushima accident. This framework can cover the internal PSA model and external PSA models (fire, flooding, and seismic PSA models) in the full power and the low power-shutdown modes. This framework also integrates level 1, 2 and 3 PSA to quantify the risk of nuclear facilities more efficiently and consistently. We expect that this framework will be helpful to resolve the issue regarding the limited scope of PSA and to reduce some inconsistencies that might exist between (1) the internal and external PSA, and (2) full power mode PSA and low power-shutdown PSA models. In addition, KAERI is starting researches related to the extreme external events, the risk assessment of spent fuel pool, and the site risk. These emerging issues will be incorporated into the integrated risk assessment framework. In this paper the integrated risk assessment framework and the research activities on the emerging issues are outlined.

• Journal of Radiation Protection and Research
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• 제28권3호
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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.

• Journal of Environmental Impact Assessment
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• 제12권3호
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• pp.151-160
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• 2003

Analysis of carrying capacity and site suitability by the systematic application of environmental information an provide a basis for implementing environmentally sensitive and sustainable resource development policies. Based on the availability of public services and environmental and site-specific constraints, a Rural Residential Density Matrix was applied in Santa Cruz County, California, USA to assess the development potential of rural land parcels since 1980. In one case, the Matrix was applied to calculate the allowable development density on a site in Lompico planned for use as a Buddhist retreat center. These calculations revealed higher environmental sensitivity and lower carrying capacity than projected in the proposed plan. Under the constraints of the county's minimum acreage policies and insufficient developable land, the developer cancelled the proposed plan. This example suggests that application of the Matrix at the concept development stage would increase the effectiveness of the prior environmental review and environmental impact assessment (EIA) system in Korea.

• Journal of the Korean Society of Safety
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• 제33권6호
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• pp.144-156
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• 2018

Level 3 Probabilistic Safety Assessment (PSA) is performed for the risk assessment that calculates radioactive material dispersion to the environment. This risk assessment is performed with a tool of MELCOR Accident Consequence Code System (MACCS2 or WinMACCS). For the off-site consequence analysis of multi-unit nuclear power plant (NPP) accident, the single location (Center Of Mass, COM) method has been usually adopted with the assumption that all the NPPs in the nuclear site are located at the same COM point. It was well known that this COM calculation can lead to underestimated or overestimated radionuclide concentration. In order to overcome this underestimation or overestimation of radionuclide concentrations in the COM method, Multiple Location (ML) method was developed in this study. The radionuclide concentrations for the individual NPPs are separately calculated, and they are summed at every location in the nuclear site by the post-processing of radionuclide concentrations that is based on two-dimensional Gaussian Plume equations. In order to demonstrate the efficiency of the ML method, radionuclide concentrations were calculated for the six-unit NPP site, radionuclide concentrations of the ML method were compared with those by COM method. This comparison was performed for conditions of constant weather, yearly weather in Korea, and four seasons, and the results were discussed. This new ML method (1) improves accuracy of radionuclide concentrations when multi-unit NPP accident occurs, (2) calculates realistic atmospheric dispersion of radionuclides under various weather conditions, and finally (3) supports off-site emergency plan optimization. It is recommended that this new method be applied to the risk assessment of multi-unit NPP accident. This new method drastically improves the accuracy of radionuclide concentrations at the locations adjacent to or very close to NPPs. This ML method has a great strength over the COM method when people live near nuclear site, since it provides accurate radionuclide concentrations or radiation doses.

• Journal of Radiation Protection and Research
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• 제13권2호
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• pp.67-77
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• 1988

The necessity of developing a rapid dose assessment system has been emphasized for an effective emergency response of mitigation of off-site radiological consequences. A microcomputer program based on a rapid dose assessment model of the off-site radiological consequences is developed for various accdident sinarios for the Nuclear Power Plants in Korea. This model, which is consists of the user answering-question input format as a menu driven method and the output format of table and graphic types, is helpful to decision-making on Emergency Preparedness by being more rapidly able to implement the off-site dose assessment and to interpret the result.

• International conference on construction engineering and project management
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1231-1236
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• 2009

Many work-related risk factors can cause construction site hazards. Therefore, safety management begins with measuring the magnitude of risk involved in a project. This study proposes a methodology for risk assessment of major trades at a particular construction site. To assess risk, this methodology integrates hazard severity and frequency, and their magnitude is calculated based on actual work-site hazards. This methodology also considers the influence factors that affect the frequency of work-related hazards. To select the appropriate influence factors, a two step approach is deployed. First, the predominant factors are identified through a literature review. Second, a selective process filters out the influence factors that are difficult to analyze quantitatively, and these extracted factors are weighted using expert surveys. Finally, the factors are combined and a quantitative risk assessment methodology is proposed.