• Nuclear Engineering and Technology
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• 제43권2호
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• pp.175-186
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• 2011

Previous evaluations of the safety of the Ulchin Nuclear Power Plant in the event of a tsunami have the shortcoming of uncertainty of the tsunami sources. To address this uncertainty, maximum and minimum wave heights at the intake of Ulchin NPP have been estimated through a parametric study, and then assessment of the safety margin for the intake has been carried out. From the simulation results for the Ulchin NPP site, it can be seen that the coefficient of eddy viscosity considerably affects wave height at the inside of the breakwater. In addition, assessment of the safety margin shows that almost all of the intake water pumps have a safety margin over 2 m, and Ulchin NPP site seems to be safe in the event of a tsunami according to this parametric study, although parts of the CWPs rarely have a margin for the minimum wave height.

• Nuclear Engineering and Technology
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• 제42권4호
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• pp.365-376
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• 2010

This paper summarizes the results of a Writing Group on the Extension of CFD codes to two-phase flow safety problems, which was created by the Group for Analysis and Management of Accidents of the Nuclear Energy Agency' Committee on the Safety of Nuclear Installations (NEA-CSNI). Two-phase CFD used for safety investigations may predict small scale flow processes, which are not seen by system thermalhydraulic codes. However, the two-phase CFD models are not as mature as those in the single phase CFD and potential users need some guidance for proper application. In this paper, a classification of various modelling approaches is proposed. Then, a general multi-step methodology for using two-phase-CFD is explained, including a preliminary identification of flow processes, a model selection, and a verification and validation process. A list of 26 nuclear reactor safety issues that could benefit from investigations at the CFD scale is identified. Then, a few issues are analyzed in more detail, and a preliminary state-of-the-art is proposed and the remaining gaps in the existing approaches are identified. Finally, guidelines for users are proposed.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2716-2727
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• 2021

The core shroud is one of the most important internal components of the reactor vessel internals because it meets the neutron fluence directly emitted by the nuclear fuel. In particular, dynamic effects for an earthquake should be evaluated with respect to the neutron irradiation flux. As a prerequisite to this study, simplified and detailed finite element models are developed for the core shroud using the ANSYS Design Parametric Language. Using the El Centro earthquake, seismic analyses are performed for the simplified and detailed core shroud models. Modal characteristics are obtained and their results are used for a time history analysis. Response spectrum analyses are also performed to access the degree of seismic excitation. The results of these analyses are compared to investigate the response characteristics between the simplified and detailed core shroud models from the time history and response spectrum analyses.

• Nuclear Engineering and Technology
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• 제51권5호
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• pp.1289-1296
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• 2019

Non-functional requirements plays a critical role in designing variety of applications domain ranges from safety-critical systems to simple gaming applications. Performance is one of the crucial non-functional requirement, especially in control and safety systems, that validates the design. System risk can be quantified as a product of probability of system failure and severity of its impact. In this paper, we devise a technique to do the performance analysis of safety critical and control systems and to estimate performance based risk factor. The technique elaborates Petri nets to estimate performability to ensure system dependability requirements. We illustrate the technique on a case study of Nuclear Power Plant system. The technique has been validated on 17 safety critical and control systems of Nuclear Power Plant.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2690-2701
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• 2022

In this paper, we select important fission products for the estimation of the source term during a severe accident of a PWR. The selection is based on the numerical results obtained from depletion calculations for the typical PWR fuel via the in-house code named DEGETION (Depletion, Generation, and Transmutation of Isotopes on Nuclear Application), release fractions of the fission products derived from NUREG-1465, and effective dose conversion coefficients from ICRP 119. Then, for the selected fission products, we obtain the adjoint solutions of the Bateman equations for radioactive decay in order to determine the importance of precursors producing the aforementioned fission products via radioactive decay, which would provide insights into the assumption used in MACCS 2 for a level 3 PSA analysis in which up to six precursors are considered in the calculations of radioactive decays for the fission product after release from the reactor.

• Nuclear Engineering and Technology
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• 제53권5호
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• pp.1454-1463
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• 2021

Demographics, personality traits and attitudes are related to safety behaviors in varied workplaces, but their roles in nuclear power plants (NPPs) have not been fully understood. This study was conducted to explore the roles of a set of demographic, personality and attitudinal factors on self-reported safety behaviors (including safety participation and human errors) among NPP commissioning workers. Survey data were collected from 157 Chinese commissioning workers. Results showed that age and work experience were significantly associated with human errors, but not with safety participation. Neuroticism and conscientiousness were significantly related to human errors, while neuroticism, conscientiousness and agreeableness were significantly related to safety participation. Attitude towards questioning was observed as an antecedent of safety participation, and functioned as a mediating variable in the relation between conscientiousness and safety behaviors. The findings provide evidence-based implications on the design of diverse interventions and strategies for the promotion of safety behaviors in NPPs.

• 대한안전경영과학회지
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• 제14권1호
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• pp.53-63
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• 2012

The purpose of this study is to grasp foreign worker's industrial safety and health state, which find out the improvement to secure the basic safety net for foreign workers. We have investigated 2,050 workers through direct interviews during the period from April 12, 2010 to May 31, 2010. And the result of analysis, foreign worker's daily average working time is 10.6 hours(40.8% workers in total work 10~12 hours), the extent of exposure to harmful and dangerous working environment is 'the position which cause pain in neck, waist, hands, shoulders, legs'(69.3%), 'repetitive hands and arms movement'(66.1%). It showed 'experience of accident damage or disease related work'(27.3%), 'never apply for industrial accident compensation' is revealed high at 73%. As a result of completing a safety health education for a year, it showed 'never educated'(40.2%), 'the institute that foreign workers have used for help and advice is the foreign worker's support center'(61.9%) Thus, hiring foreign workers in the company are small in site, the environment is too harmful and dangerous. In addition, no safety and health managers, legally blind spot located in the health and safety, because it is an urgent meet for these measures to improve.

• 한국전자통신학회논문지
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• 제13권1호
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• pp.169-174
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• 2018

시민들의 안전을 위한 영상통합관제센터에는 수많은 CCTV 카메라가 연결되어 많은 채널의 영상을 소수의 관제사가 관제하는데 어려움이 있다. 본 논문에서는 많은 채널의 영상을 효과적으로 관제하기 위하여 안전지도와 연계한 지능형 영상보안 시스템을 제안한다. 안전지도는 범죄 발생 빈도를 데이터베이스로 구축하고, 범죄 발생 위험 정도를 표현하고, 범죄 취약 계층인 여성이 범죄 위험 지역으로 진입하면 영상통합관제센터의 관제사가 주목할 수 있도록 한다. 성별 구분을 보행자 검출 및 추적 그리고 딥러닝을 통하여 성별을 구분한다. 보행자 검출은 Adaboost 알고리즘을 이용하고, 보행자 추적을 위한 확률적 데이터 연관 필터(probablistic data association filter)를 적용한다. 보행자의 성별을 구분하기 위하여 비교적 간단한 AlexNet를 적용하여 성별을 판별한다. 실험을 통하여 제안하는 성별 구분 방법이 종래의 알고리즘에 비하여 성별 구분에 효과적임을 보인다. 또한 안전지도와 연계한 지능형 영상보안 시스템 구현 결과를 소개한다.

• 대한안전경영과학회지
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• 제23권4호
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• pp.11-21
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• 2021

In order to explore the job crafting experience of millennial safety workers, this study conducted a qualitative case research with five safety workers of S Energy from March 26 to September 27, 2021 . As a result of the analysis, task crafting showed 'matching one's strong suit with a given task', 'expanding work knowledge using social network service (SNS)', and 'making changes in job performance methods for preemptive safety management activities'. Also, Cognitive crafting showed 'recognition of social vocation as a safety job', 'recognition of a role to grow as a safety management expert', and 'cognitive changes from means of organizational adaptation to enjoyment and energy of life'. At the same time, in relation crafting, 'establishment of amicable relationships through SNS in non-face-to-face and rapid communicating situations', 'safety management made through with mutual cooperations between business people', and 'reborn as a mutual safety net in business relationships' appeared. These can be used as basic data to accumulate the theoretical basis for job crafting research of millennial safety workers and to improve their job satisfaction. A follow-up study was proposed for safety workers with occupations of various kinds.

• Nuclear Engineering and Technology
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• 제50권1호
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• pp.25-34
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• 2018

The CINDER code has about 60 years of development history, and is thus one of the world's best transmutation computing codes to date. Unfortunately, it is complex and cumbersome to use. Preparing auxiliary input files for activation computation from MCNPX output and executing them using Perl script (activation script) is the first difficulty, and separation of gamma source computing script (gamma script), which analyzes the spectra files produced by CINDER code and creates source definition format for MCNPX code, is the second difficulty. In addition, for highly nonlinear problems, multiple human interventions may increase the possibility of errors. Postprocessing such as making plots with large text outputs is also time consuming. One way to improve these limitations is to make a graphical user interface wrapper that includes all codes, such as MCNPX and CINDER, and all scripts with a visual C#.NET tool. The graphical user interface merges all the codes and provides easy postprocessing of graphics data and Microsoft office tools, such as Excel sheets, which make the CINDER code easy to use. This study describes the VCINDER code (with visual C#.NET) and gives a typical application example.