• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2438-2446
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• 2023

To cool down a nuclear reactor core and prevent the fuel damage without a pump-driven active component during any anticipated accident, the passive emergency core cooling system (PECCS) was designed and adopted in an advanced light water reactor, i-POWER. In this study, for a validation of the cooling capability of PECCS, thermal-hydraulic integral effect tests were performed with the ATLAS facility by simulating intermediate and small break loss-of-coolant accidents (IBLOCA and SBLOCA). The test result showed that PECCS could effectively depressurize the reactor coolant system by supplying the safety injection water from the safety injection tanks (SITs). The result pointed out that the safety injection from IRWST should have been activated earlier to inhibit the excessive core heat-up. The sequence of the PECCS injection and the major thermal hydraulic transient during the SBLOCA transient was similar to the result of the IBLOCA test with the equivalent PECCS condition. The test data can be used to evaluate the capability of thermal hydraulic safety analysis codes in predicting IBLOCA and SBLOCA transients under an operation of passive safety system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.244-246
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• 2006

Softwares in railway system are being used in the area of railway control system, directly associated to safety. Because the instinct characteristic of Software is uncertainty, Software development without safety insurance is very hazardous situation. In order to derive safety certification process in the railway system, certification and approval processes in the nuclear, aviation, and military area are studied. Software quality should be improved by two aspects : one is product aspect, another is process aspect. GS(Good Software) and ES(Excellent Software) certification can be exemplified in a product aspect approach. In those process certification, CMMI (Capability Maturity Model Integration) or SPICE (Software Process Improvement and Capability dEtermination : ISO/IEC15504) is being used as models for assessing process maturity of organization. Following the studies, safety management procedure in the railway system is suggested.

• 한국안전학회지
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• 제13권4호
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• pp.59-70
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• 1998

In this study, response time index(RTI) of standard and quick response type sprinkler head are measured and compared through ramp and plunge test in heated wind tunnel. Also discharge rate and water distribution, actual delivered density(ADD), fire test with wood cribs are performed to compare the fire suppression capability and the operation time and temperature between standard and quick response type sprinkler head.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2011년도 추계학술대회
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• pp.551-556
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• 2011

This research presents an implementation strategy of Process Capability Index (PCI) according to the types of process characteristics. The types of process feature are classified as four perspectives of variation range, time period, error position, and process stage. The paper examines short-term or long-term PCI, within or between variation, position of precision or accuracy, and inclusion of measurement or calibration stage. Moreover, the study proposes normality test of unilateral PCI.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.316-318
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• 2006

It can be considered that the safety of software is combined with that of hardware, and also directly connected to system safety. Because the software in the railway system takes the form of Embedded that let it behave at the system level, instead of independent operation, the safety of the railway S/W is also important. The approach, for ensuring the quality and safety of those software, can be considered with two points of view. Those are views seeing from products, and from processes. The two points of approach are all necessary in the railway system. For the first of all, the process approach is to validate maturity of the organizations in accordance to the judging processes of organizations, which are specified by CMMI(Capability Maturity Model Integration) or SPICE(Software Process Improvement and Capability dEtermination: ISO/IECl5504). In this paper, as the first step of them, we are trying to find approaches to estimate the maturity of manufacturer and assessment organization in the railway system.

• 해양환경안전학회지
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• 제1권2호
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• pp.1-15
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• 1995

Almost of all impediments to enhancing ship safety and preventing vessel-source marine pollution arise from the interaction between direct and indirect factors. The direct factors come from human errors and failure in compliance with the international convention standards for the operation of cessel. The indirect factors derive from the will and attitudes of the countries taking little responsibilities with appropriate seriousness for policing their fleets. By focusing on these aspects, this paper reviews the effectiveness of existing countermasures adopted by IMO and intends to propose a new paradigm to improve the implementation capability of each nation by suggesting frameworks of maritime administration models.

• 대한안전경영과학회지
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• 제11권2호
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• pp.117-126
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• 2009

We develop methods for propagating and analyzing EPCI(Extended Process Capability Index) by using the error type that classifies into accuracy and precision. EPCI developed in this study can be applied to the three combined processes that consist of production, measurement and calibration. Little calibration work discusses while a great deal has been studied about SPC(Statistical Process Contol) and MSA(Measurement System Analysis). EPCI can be decomposed into three indexes such as PPCI(Production Process Capability Index), PPPI(Production Process Performance Index), MPCI(Measurement PCD, and CPCI(Calibration PCI). These indexs based on the type of error classification can be used with various statistical techniques and principles such as SPC control charts, ANOVA(Analysis of Variance), MSA Gage R&R, Additivity-of-Variance, and RSSM(Root Sum of Square Method). As the method proposed is simple, any engineer in charge of SPC. MSA and calibration can use efficientily in industries. Numerical examples are presentsed. We recommed that the indexes can be used in conjunction with evaluation criteria.

• 한국건설관리학회논문집
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• 제21권3호
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• pp.65-75
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• 2020

본 연구에서는 건설업 작업종사자들을 대상으로 회사의 건설안전관리시스템, 작업자들의 안전의식과 안전준수행동 간의 영향 관계를 검증하는 것을 목적으로 하였다. 작업종사자 357명을 대상으로 설문조사를 수행하였으며, SPSS 25.0 프로그램을 이용하여 통계적 분석을 수행하였다. 그 결과 다음과 같은 주요 결과를 도출하였다. 첫째, 건설안전관리시스템이 작업자 안전의식에 미치는 영향을 검증한 결과, 건설안전관리시스템 요인인 관리감독자 역량, 사내 건설안전관리, 건설안전교육, 건설재해 평가 모두 작업자의 안전의식에 유의미한 정(+)의 영향을 미치는 것으로 나타났다. 둘째, 작업자의 안전의식이 안전준수행동에 미치는 영향을 검증한 결과, 작업자의 안전의식은 안전준수행동에 유의미한 정(+)의 영향을 미치는 것으로 나타났다. 셋째, 건설안전관리시스템이 안전준수행동에 미치는 영향을 검증한 결과, 건설안전관리시스템 요인인 관리감독자 역량, 사내 건설안전관리, 건설안전교육, 건설재해 평가 요인 모두 안전준수행동에 유의미한 정(+)의 영향을 미치는 것으로 나타났다. 또한, 본 연구를 통해 작업자의 안전의식과 안전준수행동을 높이기 위해서는 작업현장의 안전을 담당하는 관리감독자 역량이 가장 중요한 안전관리 요인임을 확인하였다.

• 한국항공운항학회지
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• 제29권1호
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• pp.38-46
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• 2021

The Organization's ability to respond to social disasters has begun to be treated as important through social shock situations that have never been experienced, such as COVID-19. Among them, the ability to respond to unexpected risks and resilience is emerging. Since social disasters such as infectious diseases are periodically repeated, compounded, and enlarged, they develop into a global crisis situation, so this crisis response capability is treated as national competitiveness. Therefore, this study aims to improve the organization's response capability in terms of risk response and resilience under rapid social disasters such as COVID-19. The aviation safety field was taken as an example. From the Safety-II perspective, safety management focuses on the ability to resilience in response to system vulnerabilities in various situations. In this study, I intend to apply RAG(Resilience Assessment Grid) of Respond, Monitor, Learn and Anticipate, the four major potential of resilience engineering. Based on Hollnagel's research, potential elements were classified into four, and items were organized through an expert panel using Delphi techniques. The final configured RAG items are 15 Respond, 15 Monitor, 15 Learn and 11 Anticipate. The RAG was evaluated by 42 experts in the field of aviation safety.

• 한국안전학회지
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• 제35권4호
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• pp.84-91
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• 2020

The Korean nuclear industry developed the SPACE (Safety and Performance Analysis Code for nuclear power plants) code and this code adpots two-phase flows, two-fluid, three-field models which are comprised of gas, continuous liquid and droplet fields and has a capability to simulate three-dimensional model. According to the revised law by the Nuclear Safety and Security Commission (NSSC) in Korea, the multiple failure accidents that must be considered for accident management plan of nuclear power plant was determined based on the lessons learned from the Fukushima accident. Generally, to improve the reliability of the calculation results of a safety analysis code, verification work for separate and integral effect experiments is required. In this reason, the goal of this work is to verify calculation capability of SPACE code for multiple failure accident. For this purpose, it was selected the experiment which was conducted to simulate a Multiple Steam Generator Tube Rupture(MSGTR) accident with Passive Auxiliary Feedwater System(PAFS) operation by Korea Atomic Energy Research Institute (KAERI) and focused that the comparison between the experiment results and code calculation results to verify the performance of the SPACE code. The MSGR accident has a unique feature of the penetration of the barrier between the Reactor Coolant System (RCS) and the secondary system resulting from multiple failure of steam generator U-tubes. The PAFS is one of the advanced safety features with passive cooling system to replace a conventional active auxiliary feedwater system. This system is passively capable of condensing steam generated in steam generator and feeding the condensed water to the steam generator by gravity. As the results of overall system transient response using SPACE code showed similar trends with the experimental results such as the system pressure, mass flow rate, and collapsed water level in component. In conclusion, it could be concluded that the SPACE code has sufficient capability to simulate a MSGTR accident.