Following a surge of interest in multi-unit risk the last few years, many recent studies have suggested methods for probabilistic safety assessment (MUPSA) and addressed several related aspects. Most existing though focused on two-unit nuclear power plant (NPP) sites or used rather simplified (PSA) models to demonstrate proposed approaches. When considering an NPP site with three more units, some approaches are inapplicable yield very conservative results. Since number such is increasing,...

To secure the seismic performance of structures, risk assessment is necessary to quantify safety against beyond-design-based earthquakes and design. For input ground motions corresponding intensity for evaluation are required as loads, which must reflect tectonic characteristics site conditions. In this study, recorded in regions low moderate seismicity were used generate examples assessment. A uniform hazard spectrum (UHS) was target assessment, following guidelines. The magnitude distance...

Probabilistic safety assessment (PSA) of nuclear facilities on external multi-hazards has become a major issue after the Fukushima accident in 2011. However, existing hazard PSA methodology is for single events and cannot cover impact multi-hazards. Therefore, this study proposes quantifying multi-hazard risks energy plants. Specifically, we developed an efficient based probability distribution-based Boolean algebraic approach sampling-based method, which are currently single-hazard...

Structures in a nuclear power system are designed to be elastic even under an earthquake excitation. However structural component such as isolator shows inelastic behavior inherently. For the seismic assessment of nonlinear structures, response history analysis should performed. In this study, base isolation was analyzed by for performance assessment. Firstly, several criteria plant structure were reviewed analysis. Based on these criteria, spectrum matched ground motion generation method...

For the important safety system, two or more units of identical equipment redundant components with similar function were installed to prevent abnormal failure. If failure probability such is independent, this redundancy could increase system remarkably. However, if each component highly correlated by installing in a structure experiencing an earthquake event, expected effect will decrease. Therefore, seismic correlation should be evaluated quantitatively for probabilistic assessment. The...

Recently, a base isolation system used to be introduced for the seismic safety of nuclear power plants. The should keep its function over design level earthquake with high confidence like any other equipment in response isolators by extended earthquakes controlled not exceed ultimate limit state it. In this study, lead-rubber bearings (LRBs) were tested. small scale test specimen LRB had 550 mm diameter and full was 1,500 diameter. displacement horizontal displacements applied specimens...

There has been an increasing demand for introducing a base isolation system to secure the seismic safety of nuclear power plant. However, design criteria and assessment methodology isolated facility are still being developed. A performance based concept needs be added general procedures. For system, displacement responses isolators excited by extended basis earthquake important as well displacement. The possible response should limited less than failure isolator. were investigated...

어류 양식장 인근에서 건설공사로 인하여 발생하는 소음 진동의 경우 피해 금액과 산정방식 선정은 건설공사에 대한 공종별 전문가의 공학적, 기술적 의견이 배제된 상태에서 이루어지고 있다. 피해자 측이 일방적으로 전문가들의 생물학적 자문 위주의 논리만 주장하는 반면, 어류에 전문지식이 부족한 건설사 측은 일반적인 건설소음 진동에 관한 논리를 전개하는 경우가 대부분이다. 그래서 중앙 환경 분쟁 조정위원회에서는 2009년 진동으로 인한 육상 양식어류 평가 및 배상액 산정기준에 연구를 통해 구체적인 피해기준을 제시하였다. 국내의 수중소음 피해인정 기준을 140 dB re <TEX>$1{\mu}Pa$</TEX>을 인정하고 이 기준은 충격음이 아닌 1초 이상의 연속음의 RMS 값이다. 또한, 기존 연구 자료들을 보면 어류는 골표류와 비골표류, 기각류와 비기각류 등 어종에 따라서 수중소음에 반응이 많은 차이가 있는 것으로 보인다. 본 연구는 충격음과 특성 차이를 고려하여 충격음의 제시하려...

The development of a floor response spectrum (FRS) is very important for seismic risk assessment nuclear power plants. In the case non-isolated plants, methodology regarding FRS generation has already been developed. But in isolated NPP structure, developing not determined yet. Therefore, this study, shaking table tests frame structure were performed spectrum. For test, two-story artificial was manufactured. isolation devices, lead rubber bearing and an EradiQuake system (EQS) used. An input...

To evaluate the seismic safety of components in a structure, an in-structure response spectrum (ISRS) must be obtained, and this also applies to seismically isolated structures. The main variables for designing isolators are effective stiffness damping, which can given as characteristic strength secondary nonlinear behaviors. Many studies on ISRS structures have been conducted effects these two isolators, but effect other related hysteresis curve needs studied. This study focused initial...

The IPv6 network protects the IP layer by using IPSec protocol and SEND mechanism. However each host should be authenticated repeatedly when two mechanisms are used at same time. In this paper, we propose a cooperation scheme to share authentication information between mechanism protocol. By sharing data of with mechanism, expects cost reduction for establishing secure communication channel. We also evaluate performance proposed implementing scheme.