• 농약과학회지
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• 제17권1호
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• pp.60-64
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• 2013

본 연구는 우리나라 논농사 농약살포자의 농약 노출량 산정과 위해성 평가를 위하여 수행되었다. 우리나라 논에 사용되고 있는 약제 중 분무의 형태로 이용되는 단제 48품목에 대하여 사용방법에 대한 정보를 수집하였고, 이를 근거로 농약 노출량을 산정하였다. 산정된 노출량을 세계 각 기관에서 발표된 농작업자 노출허용량과 비교하여 위해성을 평가하였다. 동력분무기를 이용하여 농약을 살포하는 경우 개인보호장비(PPE)를 착용하지 않은 경우 17개의 품목에서 위해성이 있는 것으로 나타났으며, 개인보호장비를 착용한 경우에도 6개의 품목에서 위해성을 나타내었다. 이러한 결과는 논에서 농약을 살포하는 경우 농약살포자의 농약노출로 인한 위해성이 높다는 것을 의미하고 있었다.

• 농약과학회지
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• 제17권1호
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• pp.50-59
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• 2013

본 연구는 우리나라 과수 농약살포자의 농약 노출량 산정과 위해성 평가를 위하여 수행되었다. 우리나라 과수에 사용되고 있는 약제 중 분무의 형태로 이용되는 97종의 품목에 대하여 사용방법에 대한 정보를 수집하였고, 이를 근거로 농약 노출량을 국내실정에 맞게 변형한 UK-POEM(United Kingdom-Predicted Operator Exposure Model)모델을 이용하여 산정하였다. 산정된 노출량을 세계 각 기관에서 발표된 농약살포자 노출허용량과 비교하여 위해성을 평가하였다. Speed sprayer (SS기)를 이용하여 살포작업을 하는 경우 개인보호장비(PPE)를 착용하지 않았을 때 74.2%, 개인 보호장비를 착용하였을 때 42.3%가 위해성이 있는 것으로 나타났다. 또한 동력분무기(MS기)를 이용하였을 경우 개인보호장비(PPE)를 착용하지 않았을 때 64.1%, 개인 보호장비를 착용하였을 때 19.4%가 위해성이 있는 것으로 나타났다. 이러한 결과는 현재 우리나라 과수 농약살포자의 농약 노출로 인한 위해성이 우려된다는 것을 의미한다.

• 한국안전학회지
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• 제27권5호
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• pp.229-234
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• 2012

Operator's action time is evaluated from MAAP4 analysis used in conventional probabilistic safety assessment(PSA) of a nuclear power plant. MAAP4 code which was developed for severe accident analysis is too conservative to perform a realistic PSA. A best-estimate code such as RELAP5/MOD3, MARS has been used to reduce the conservatism of thermal hydraulic analysis. In this study, operator's action time of core cooling recovery operation is evaluated by using the MARS code, which its Fussell-Vessely(F-V) value was evaluated as highly important in a small break loss of coolant(SBLOCA) event and loss of component cooling water(LOCCW) event in previous PSA. The main conclusions were elicited : (1) MARS analysis provides larger time window for operator's action time than MAAP4 analysis and gives the more realistic time window in PSA (2) Sufficient operator's action time can reduce human error probability and core damage frequency in PSA.

• 한국안전학회지
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• 제33권6호
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• pp.136-143
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• 2018

In this study, we conducted a pilot study on the multiple spurious operations (MSO) analysis in the fire probabilistic safety assessment (PSA) of domestic nuclear power plant (NPP) to identify the degree of influence of the operator actions used in the MSO mitigation strategies. The MSO scenario of the domestic reference NPP selected for this study is refueling water tank (RWT) drain down event. It could be caused by spurious operations of the containment spray system (CSS) of the reference NPP. The RWT drain down event can be stopped by the main control room (MCR) operator actions for stopping the operation of CSS pump or closing the CSS motor operated valve if the containment spray actuation signal (CSAS) is spuriously actuated. Outside the MCR, it can be stopped by operator actions for closing the CSS manual valves or motor operated valve or stopping the operation of CSS pump. The quantification result of a fire PSA model that takes into account all recovery actions for the RWT drain down event lead to risk reduction by about 95%, compared with quantification result of fire PSA model without considering them. Among the various operator actions, the recovery action for the spurious CSAS operations and the operator action for the manual valve are identified as the most important operator actions. This study quantitatively showed the extent to which the operator actions used as MSO countermeasures have affected the fire PSA quantification results. In addition, we can see the rank of importance among the operator recovery actions in quantitative terms.

• 한국시스템다이내믹스연구
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• 제16권1호
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• pp.53-74
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• 2015

The purpose of this paper is to simulate public trust on nuclear regulation policy. The first of all, public trust variables and the model were developed and analysed by system dynamic method. The model are consisted of the operator safety culture level, regulatory competence levels, the public satisfaction and public trust level. The scenario is made up three type which base scenario, the system operator's safety culture level and accident event level. First. the simulation results of standard scenario shows that rapidly declining public satisfaction and trust level of the national safety after Japan's nuclear accident in November 2011. Second, operator safety culture level and simulated divided into three levels. The results showed that a greater impact on the public satisfaction if bad than good case. Finally, the size of the accident was simulated divided into three levels levels(no accident, medium, serious accidents). the results showed a weak effect against the regulatory capacity and safety performance levels but showed a significant impact on public satisfaction and confidence level.

• Nuclear Engineering and Technology
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• 제52권9호
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• pp.1983-1989
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• 2020

The human reliability analysis is a method by which, in general terms, the human impact to the safety and risk of a nuclear power plant operation can be modelled, quantified and analysed. It is an indispensable element of the PSA process within the nuclear industry nowadays. The paper herein presents a sensitivity study of the human reliability analysis performed on a real nuclear power plant-specific probabilistic safety assessment model. The analysis is performed on a pre-selected set of post-initiator operator actions. The purpose of the study is to investigate the impact of these operator actions on the plant risk by altering their corresponding human error probabilities in a wide spectrum. The results direct the fact that the future effort should be focused on maintaining the current human reliability level, i.e. not letting it worsen, rather than improving it.

• Nuclear Engineering and Technology
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• 제44권4호
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• pp.379-386
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• 2012

A symptom-based procedure with a critical safety function monitoring system has been established to reduce the operator's diagnosis and cognitive burden since the Three-Mile Island (TMI) accident. However, it has been reported that a symptom-based procedure also requires an operator's cognitive efforts to cope with off-normal events. This can be caused by mismatches between a static model, an emergency operating procedure (EOP), and a dynamic process, the nature of an ongoing situation. The purpose of this study is to share the evidence of mismatches that may result in an excessive cognitive burden in conducting EOPs. For this purpose, we analyzed simulated emergency operation records and observed some operator behaviors during the EOP operation: continuous steps, improper description, parameter check at a fixed time, decision by information previously obtained, execution complexity, operation by the operator's knowledge, notes and cautions, and a foldout page. Since observations in this study are comparable to the results of an existing study, it is expected that the operational behaviors observed in this study are generic features of operators who have to cope with a dynamic situation using a static procedure.

• 한국안전학회지
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• 제28권4호
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• pp.19-25
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• 2013

For safe remote control, information on remote environment has to be delivered to operator realistically, and there have been numerous research efforts on this respect. Among them, haptic technology can significantly enhance safety and overall effectiveness of remote operation by delivering various kinds of information on virtual or real environment to operator. In this study, remote control based on haptic feedback is applied to control of mobile robot moving according to the command from operator avoiding collision with environmental obstacles and maintaining safe distance from them using ultrasonic sensors. Specifically, a remote feedback control structure for mobile robot is proposed. The controller is based on the inner feedback loop that directly utilizes information on distance to obstacles, and the outer feedback loop that the operator directly commands using the haptic device on which the computed reaction force based on the distance information is acting. Effectiveness of the proposed remote control scheme using double feedback loops is verified through a series of experiments on mobile robot.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1634-1645
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• 2004

This study reveals that rail reform which separates infrastructure from train operation requires more safety activities to train operator than before. To meet these requirements the train operator, KNR, should build up more expertness, accept accidents investigation by the third party, establish and operate safety knowledge management system, and manage a forum which facilitates the communication between the parties concerned.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.2179-2194
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• 2010

RAMS is becoming increasingly important in the decision making process for the rolling stock projects in order to improve competitiveness by reducing system life cycle cost while improving reliability, availability, maintainability and safety. In order to apply and manage RAMS of rolling stock systems effectively in the operator perspective, it is essential to integrate and control RAMS systematically from the early stage of rolling stock projects. RAMS management is to implement a RAMS system into rolling stock projects in terms of a rolling stock operator, which presents the strategic directions of RAMS policy, objectives, requirements, control, analysis, measurement and improvement throughout life cycle of rolling stock projects. This article presents a new framework of RAMS management that provides an effective and efficient way for managing RAMS in rolling stock systems in the railway industry.