• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.526-535
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• 2024

This paper proposes a safety-critical standby component unavailability model that contains aging effects caused by the elapsed time from installation, component degradation due to surveillance tests, and imperfect maintenance actions. An application of the model to a Motor-Operated Valve and a Motor-Driven Pump involved in the HPIS of a VVER/1000-V446 nuclear power plant is demonstrated and compared with other existing models at component and system levels. In addition, the effects of different unavailability models are reflected in the NPP's risk criterion, i.e., core damage frequency, over five maintenance periods. The results show that, compared with other models that do not simultaneously consider the full effects of degradation and maintenance impacts, the proposed model realistically evaluates the unavailabilities of the safety-related components and the involved systems as a plant age function. Therefore, it can effectively reflect the age-dependent CDF impact of a given testing and maintenance policy in a specified time horizon.

• STI Policy Review
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• v.6 no.2
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• pp.146-173
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• 2015

This study explores how to reconcile science and policy in the wind energy sector by providing a conceptual framework for better understanding evidence-based policymaking (EBPM). Regarding this framework, the core issue is to discover how knowledge is formed over time, and which factors affect this knowledge formation. Comparative cases of wind industry emergence in Spain and Britain are examined. This analysis shows that knowledge formation initially starts in the scientific arena in parallel with its formation in the practical, and is followed by political knowledge formation near the beginning of commercial projects. Regarding knowledge formation, three more comparisons are made between wind industry emergence in Spain and Britain: the different approaches to R&D projects, the different adoptions of supporting measures, and the different ways of coping with public opposition. The factors affecting the comparisons are mainly perceptions of energy supply, nuclear power, environment and science and technology. Communication and unfamiliarity are likely to affect the comparisons in EBPM.

• Journal of Korea Technology Innovation Society
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• v.20 no.4
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• pp.1057-1088
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• 2017

This research has attempted to conduct meta-analysis on 605 published papers in the field of socio-nuclear studies from 1957 to 2016 in Korea through network analysis of author-provided keywords. The findings lead to several straightforward conclusions. First, socio-nuclear studies including policy research have mostly been conducted by universities, while technology developments have been led by public organizations. Second, it is apparent that the Fukushima accident has provoked major engagement among social scientists in nuclear issues as the remarkable growth of the knowledge network after 2011 signify. Third, the research topics have been diversified as a result of growing multi-disciplinary research projects. Finally, there is between sub communities in the socio-nuclear knowledge network in terms of network properties. This article provides a stepping stone for future researchers with a wealth of information concerning the status of socio-nuclear studies. For policy makers, this meta-analysis is likely to provide guidance on what we need and do not need. It remains to be seen whether the socio-nuclear knowledge network in Korea is well-structured or not. provide an impetus for comparative studies with overseas cases in order to evaluate the network and its soundness.

• Nuclear Engineering and Technology
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• v.51 no.8
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• pp.2034-2041
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• 2019

Public acceptance has become the most critical question for sustainable development of nuclear energy in recent decades. Many researches concentrated on risk and benefit perception, which were deemed as the most influential factors of Public Acceptance of Nuclear Energy (PANE). But few researches focused on psychological factors including regulatory focus. Therefore, this paper aimed to explore the moderating effect of regulatory focus on PANE based on Regulatory Focus Theory in order to find ways to increase/decrease PANE. An Internet-based survey had been carried out in China nationwide. The results indicated that trust in government was positively related to PANE and this relationship was mediated by risk and benefit perception. In addition, the strength of the associations between risk and benefit perception and PANE were moderated by regulatory focus, consisting of prevention focus and promotion focus. Prevention focus strengthened the negative relationship between risk perception and PANE, while promotion focus weakened. Moreover, promotion focus weakened the positive relationship between benefit perception and PANE, but no significant moderating effect of prevention focus was founded on the relationship between benefit perception and PANE. Some policy implications were also proposed on the basis of above-mentioned findings.

• Nuclear Engineering and Technology
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• v.39 no.5
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• pp.655-662
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• 2007

Most decision makers in the electricity industry plan their electric power expansion program by considering only a least cost operation, even when circumstances change with differing complexities. It is necessary, however, to analyze a long-term power expansion plan from various points of view, such as environmental friendliness, benefit of a carbon reduction, and system reliability, as well as least cost operation. The objective and approach of this study is to analyze the proper role of nuclear power in a long-term expansion plan by comparing different scenarios in terms of the system cost changes, $CO_2$ emission reduction, and system reliability in relation to the Business-As-Usual (BAU). The conclusion of this paper makes it clear that the Korean government cannot but expand the nationwide nuclear power program, because an increased energy demand is inevitable and other energy resources will not provide an adequate solution from an economic and sustainability point of view. The results of this analysis will help the Korean government in its long-term resource planning of what kinds of role each electric resource can play in terms of a triangular dilemma involving economics, environmental friendliness, and a stable supply of electricity.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.1
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• pp.65-82
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• 2018

With the significant increase in spent ion-exchange resin generation, to meet the requirements of Waste Acceptance Criteria (WAC) of the Wolsong disposal facility in Korea, blending is considered as a method for enhancing disposal options for intermediate level waste from nuclear reactors. A mass balance formula approach was used to enable blending process with an appropriate mixing ratio. As a result, it is estimated around 44.3% of high activity spent resins can be blended with the overall volume of low activity spent resins at a 1:7.18 conservative blending ratio. In contrast, the reduction of high activity spent resins is considered a positive solution in reducing the amount of spent resins stored. In an economic study, the blending process has been proven to lower the disposal cost by 10% compared to current APR1400 treatment. Prior to commencing use of this blending method in Korea, coordinated discussion, and safety and health assessment should be undertaken to investigate the feasibility of fitting this blending method to national policy as a means of waste predisposal processing and management in the future.

• Journal of Korea Technology Innovation Society
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• v.5 no.1
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• pp.90-109
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• 2002

The national nuclear R&D projects have been implemented for the purpose of supply of nuclear power which was proved to be safety and stability. Evaluating the national nuclear R&D projects has critical importance in nu-clear energy management aspect. This paper employs multi-attribute utility analysis as a basis for obtaining an evaluation index to assess the national nuclear R&D projects using a specific case study of Korea. To structure and quantify basic values for the evaluation, we elicited important attributes, then refined and structured them into a hierarchy. A multi-attribute index is constructed as a multi-attribute utility function, based on value judgments provided by a group of technical experts, policy makers, and faculties. As a result, the objective of attainment of a proposed object is given the highest priority, followed by appropriateness of project and research strategy, utilization of research output, within attribute ranges defined for the attributes. We found that the work and results of this study can provide valuable insights and decision opportunities for virtually all major decision making in evaluation of the national nuclear R&D projects in Korea.

• Nuclear Engineering and Technology
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• v.51 no.7
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• pp.1758-1764
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• 2019

As the safety level of nuclear power plants (NPPs) relates to the safety of individuals, society, and the environment, it is important to establish NPP safety goals. In Korea, two quantitative health objectives and one large release frequency (LRF) criterion were formally set as quantitative safety goals for NPPs by the Nuclear Safety and Security Commission in 2016. The risks of prompt and cancer fatalities from NPPs should be less than 0.1% of the overall risk, and the frequency of nuclear accidents releasing more than 100 TBq of Cs-137 should not exceed 1E-06 per reactor year. This paper reviews the hierarchical structure of safety goals in Korea, its relationship with those of other countries, and the relationships among safety goals and subsidiary criteria like core damage frequency and large early release frequency. By analyzing the effect of the release of 100 TBq of Cs-137 via consequence analysis codes in eight different accident scenarios, it was shown that meeting the LRF criterion results in negligible prompt fatalities in the surrounding area. Hence, the LRF criterion dominates the safety goals for Korean NPPs. Safety goals must be consistent with national policy, international standards, and the goals of other counties.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.130-137
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• 2022

In the geological repository of radioactive nuclear waste, anaerobic corrosion can generate hydrogen, and may conservatively lead to the production of hydrogen-air layer. The accumulated hydrogen may cause a hazardous flame propagation resulting from any potential ignition sources. This study numerically investigates the processes of ignition and flame propagation in the layered mixture. Simple geometry was chosen to represent the geological repository, and reactive flow simulations were performed with different ignition power, energy, and locations. The simulation results revealed the effects of power and energy of ignition source, which were also analyzed theoretically. The mechanism of layered flame propagation was suggested, which includes three stages: propagation into the hydrogen area, downward propagation due to the product gas, and horizontal propagation along the top wall. To investigate the effect of the ignition source location, simulations with eight different positions were performed, and the boundary of hazardous ignition area was identified. The simulation results were also explained through scaling analysis. This study evaluates the potential risk of the accumulated hydrogen in geological repository, and illustrates the layered flame propagation in related ignition scenarios.

• Convergence Security Journal
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• v.17 no.1
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• pp.69-79
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• 2017

This study focuses on the fact that the past government has been consistent with the one-sided withdrawal policy without any clear countermeasures in relation to the ongoing nuclear development of the DPRK. The purpose of this study is to improve the understanding of South Korea's North Korea policy and to present the direction of the North Korea policy in the future by comparing and researching the North Korea policy pursued by Lee Myung - bak government / Park-Geun-Hye government. Such an attempt will provide a basis for evaluating the previous government's policies toward North Korea, and will also help to find alternatives to sustainable inter-Korean relations and North Korea policy to achieve a unified Korea.