• Nuclear Engineering and Technology
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• 제56권2호
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• pp.410-418
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• 2024

Study of flow behavior within rod bundles has been an active topic. Surface modification technologies are important parts of the design of the fourth generation reactor, which can increase the strength of the secondary flow within the rod bundle lattices. Quasi-periodic large-scale vortex structure (QLVS) is introduced by arranging micro ribs on the surface of rod bundles, which enhanced the scale of the secondary flow between the rod bundle lattices. Using computational fluid dynamics (CFD) and water experiments, the flow field distribution and drag coefficient of the rod-bundle lattices are studied. The secondary flow between the micro-ribbed rod-bundle lattice is significantly enhanced compared to the standard rod-bundle lattice. The numerical simulation results agree well with the experimental results.

• 융합보안논문지
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• 제17권2호
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• pp.89-100
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• 2017

지난 2017년 1월, 트럼프가 미국의 제 45대 대통령으로 취임하였다. 그는 대선기간 중에 '미국 우선주의'(America First)를 적극적으로 표방하였다. 그의 이런 주장이 대외정책에 있어서 '고립주의'(Isolationism)를 표방하는 것으로 비취지고 있다. 북한의 핵위협에 대하여 미국의 '확장억제'(Extended Deterrenc)에 전적으로 의존하고 있는 한국에 있어서 이는 단순한 문제가 아니다. 즉 미국이 고립주의로 회귀하여 한미동맹 공약이행 의지가 약화되는 것으로 인식될 경우 북한의 오판 가능성은 그만큼 높아질 것이기 때문이다. 그동안 한국사회에서는 미국으로부터 안보를 지원받고 정책적 공조를 제공하는 전형적인 '비대칭 동맹'(Asymmetry Alliance)인 한미동맹의 가치를 재평가하려는 다양한 시도가 있었다. 이에 북한의 고도화된 핵도발 위협에 효과적으로 대응하고, 신장된 한국의 국력수준에 부합된 한미동맹의 효용성을 동맹이론에 입각하여 평가해보고 대책을 강구하였다. 이를 위해 본 연구는 한미동맹을 '자율성-안보 교환 모델'에 기초하여, 위협인식, 정책공조와, 동맹국으로서 가치 측면으로 구체화하여 평가해보고, 향후 한미동맹의 전략적 함의를 도출하였다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 추계학술논문요약집
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• pp.27-28
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• 2018

• 융합보안논문지
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• 제22권1호
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• pp.11-17
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• 2022

최근 사이버 공격으로 인해 발생한 우크라이나 대규모 정전 사태를 비롯하여 국가 기반시설에 대한 사이버 공격이 지속해서 발생하고 있다. 이에 따라 ICS-CERT 취약점이 작년보다 두 배 이상이 증가하는 등 원자력 시설 등의 산업제어시스템에 대한 취약점이 날로 증가하고 있다. 대부분의 제어시스템 운영자는 미국의 ICS-CERT에서 제공하는 산업제어시스템 취약점정보원을 바탕으로 취약점 대응 방안을 수립한다. 그러나 ICS-CERT는 연관된 모든 취약점 정보를 포함하지 않으며, 국내 제조사 제품에 대한 취약점을 제공하지 않아 이를 국내 제어시스템 보안에 적용하기 어렵다. 따라서 본 연구에서는 ICS-CERT에서 제공하는 제어시스템 취약점 정보(1,843건)를 기준으로 해당 취약점과 관련된 CVE, CWE, CAPEC, CPE 정보를 통합한 취약점 분석 프레임워크를 제시한다. 또한 원자력 시설의 자산을 CPE를 이용하여 식별하고 CVE와 ICS-CERT를 이용하여 취약점을 분석한다. 기존의 방법론으로 취약점 분석 시 임의의 국내 원자력 시설 자산 중 ICS-CERT에는 단 8%의 자산에 대한 취약점 정보를 탐색하였지만, 제안하는 방법론을 이용하면 70% 이상의 자산에 대해 취약점 정보를 탐색할 수 있다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2019년도 추계학술발표대회
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• pp.491-494
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• 2019

The results from the analysis of recent security breach cases of industrial control systems revealed that most of them were caused by the employees of a partner company who had been managing the control system. For this reason, the majority of the current company security management systems have been developed focusing on their performances. Despite such effort, many hacking attempts against a major company, public institution or financial institution are still attempted by the partner company or outsourced employees. Thus, the institutions or organizations that manage Industrial Control Systems (ICSs) associated with major national infrastructures involving traffic, water resources, energy, etc. are putting emphasis on their security management as the role of those partners is increasingly becoming important as outsourcing security task has become a common practice. However, in reality, it is also a fact that this is the point where security is most vulnerable and various security management plans have been continuously studied and proposed. A system that enhances the security level of a partner company with a Virtual Desktop Infrastructure (VDI) has been developed in this study through research on the past performances of partner companies stationed at various types of industrial control infrastructures and its performance outcomes were statistically compiled to propose an appropriate model for the current ICSs by comparing vulnerabilities, measures taken and their results before and after adopting the VDI.

• 정보보호학회논문지
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• 제29권5호
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• pp.973-983
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• 2019

정보 보안의 중요성은 응용 소프트웨어의 보안으로 인해 국가, 조직 및 개인 수준에서 점점 더 강조되고 있다. 임베디드 소프트웨어를 포함하는 높은 안전성 소프트웨어의 개발 기술은 항공 및 원자력 분야 등 에 국한되어 사용되었다. 하지만 이러한 소프트웨어 유형은 이제 응용 소프트웨어 보안을 향상시키는 데 사용된다. 특히 보안 코딩은 방어적 프로그래밍을 포괄하는 개념으로 소프트웨어 보안을 향상시킬 수 있다. 본 논문에서는 개선된 코딩 표준 검색 기법을 적용한 소프트웨어 보안 취약성 탐지 기술을 제안한다. 공개된 정적 분석 도구는 소프트웨어 보안 가능성을 분석하고 취약점을 유발하는 명령어를 분류하는 데 사용되었으며, 소프트웨어 취약점을 유발할 수 있는 API 및 버그 패턴을 쉽게 감지하여 향상시킬 수 있다.

• Nuclear Engineering and Technology
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• 제52권3호
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• pp.654-659
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• 2020

The reliability of the spent fuel pool instrument is very important for the security of nuclear power plant, especially during the earthquake. The effect of the fluid force on the vibration characteristics of the flexible tube of the spent fuel pool instrument needs comprehensive analysis. In this paper, based on the potential flow theory, the hydrodynamic pressures acting on the flexible tube were obtained. A mathematical model of a flexible tube was constructed to obtain the dynamic response considering the effects of seismic load and fluid force, and a computer code was written. Based on the mathematical model and computer code, the maximum stresses of the flexible tube in both safe shutdown earthquake and operating basis earthquake events on the spent fuel pool with three typical water levels were calculated, respectively. The results show that the fluid force has an obvious effect on the stress and strain of the flexible tube in both safe shutdown earthquake and operating basis earthquake events.

• Nuclear Engineering and Technology
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• 제52권4호
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• pp.674-680
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• 2020

We used MCNP6 computer code to model HTR-10 core reactor. We used two types of fuel; UO₂ and (Th+Pu)O₂ mixture. We determined the critical height at which the reactor approached criticality in both two cases. The neutronic and burnup parameters were investigated. The results indicated that the core fueled with mixed (Th+Pu)O₂, achieved about 24% higher fuel cycle length than the UO₂ case. It also enhanced safeguard security by burning Pu isotopes. The results were compared with previously published papers and good agreements were found.

• 전기학회논문지
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• 제61권11호
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• pp.1565-1570
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• 2012

Nuclear power generation is increasing domestic power supply ratio by lower CO2 emission and fuel prices. Currently, nuclear power generator has been operated with maximum power output. Therefore, nuclear power generator could be no effect to managing the reactive power reserve on power system. The reactive power reserve is calculated to the difference between maximum facility and operation generation capacity of the power system. This paper was proposed that load following of nuclear power is control by using 15-bus power system model. In the simulation result, power system is shown to safety state by operating load following of nuclear power generator. This method has be improved the supplied reliability through economic and efficient operation.

• Nuclear Engineering and Technology
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• 제39권6호
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• pp.691-696
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• 2007

Nuclear energy programs around the world increasingly find themselves at the nexus of potentially conflicting demands from both domestic and international stakeholders. On one side, the rapid growth in demand for electricity coupled with the goal of reducing carbon emissions calls for a significant expansion of nuclear energy. On the other, stakeholders are seeking ever greater safety, environmental, security, and nonproliferation assurances before consenting to the construction of new nuclear energy facilities. Satisfying the demand for clean energy supplies will require nuclear energy operators to find new and innovative ways to build confidence among stakeholders. This paper discusses two related concepts which can contribute to meeting the needs of key stakeholders in cost effective and efficient ways. Structured processes and tools for assessing stakeholder needs can build trust and confidence while facilitating the "designing-in" of information collection systems for new facilities to achieve maximum efficiency and effectiveness. Integrated approaches to monitoring facilities and managing the resulting data can provide stakeholders with continued confidence while offering operators additional facility and process information to improve performance.