• Nuclear Engineering and Technology
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• 제56권11호
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• pp.4587-4600
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• 2024

Based on the lessons from the Fukushima accident, new strategies to mitigate the spread of accidents in nuclear power plants have been established that consider portable equipment. The diverse and flexible coping strategies (FLEX) and multi-barrier accident coping strategy (MACST) based on the utilization of portable equipment are being adopted in case of an extended loss of all AC power and loss of ultimate heat sink. In this context, the establishment of specific strategies for utilizing portable equipment has emerged as an important issue. This study proposes a multi-unit probabilistic safety assessment (MUPSA)-based evaluation framework consisting of several steps to quantitatively assess the reduction in risk from the use of portable equipment at a multi-unit site, which can provide a basis for establishing optimal portable equipment strategies. According to the framework, after first defining the scope of the evaluation, risk-significant types of portable equipment are selected and the scenarios are analyzed. Risk reduction is then evaluated using modified MUPSA models according to the deployment of the portable equipment. A case study was conducted for an internal loss of off-site power (LOOP) and seismic LOOP focusing on how to evaluate the effectiveness of portable equipment through the developed framework.

• 한국안전학회지
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• 제38권3호
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• pp.110-120
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• 2023

Following the Fukushima accident, portable equipment employed as accident mitigating systems have been installed and operated to reduce core damage and large early release frequencies. In addition, the establishment of an accident management strategy has gained importance. This study investigated the current status of portable equipment including the international portable equipment FLEX (diverse and flexible coping strategies), and domestic portable equipment multi-barrier accident coping strategy (MACST). Research on optimal utilization of MACST remains insufficient. As a preliminary study for establishing an optimal strategy, sensitivity studies were conducted to facilitate the priority of use on portable equipment, number of portable equipment, and dependency of operator actions based on a multi-unit probabilistic safety assessment model. The results revealed the conditions that reduced the multi-unit and site conditional core damage probabilities, indicating the optimal strategy of MACST. The results of this study can be used as a reference for establishing an optimal strategy that utilizes domestic safety equipment in the future.

• 대한토목학회논문집
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• 제31권6D호
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• pp.765-769
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• 2011

기존의 이동식 기준장비는 갓길의 폭이 1.5m 이하인 도로 구간에는 설치가 어려우며 장비가 크고 무거워서 차량과의 충돌 시 피해가 클 수 있으며 한 번에 다차로 검지가 불가능하다. 본 연구에서는 이러한 문제점을 노정하고 있는 기존의 이동식 기준장비의 단점을 극복하기 위하여 연구 개발된 USN-기반 이동식 기준장비의 특징을 기술하고 그 성능수준을 현장 적용을 통하여 평가하였다. 그 결과 본 연구에서 개발된 장비는 기존의 이동식 기준장비가 가지고 있는 운영상의 단점을 극복할 뿐 아니라 기준장비가 가져야 할 성능수준을 만족하는 것으로 나타났다.

• 한국안전학회지
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• 제29권3호
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• pp.8-13
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• 2014

Accidents involving portable ranges occurred total 133 cases for the last five years(2008~2012). It accounted for 18.0% of all gas accidents(739 cases). Major causes of accidents are using of excessive hot grill, leaving a butane can near fire and overheating of a butane can during cooking. In this study, it is a desire to investigate the relationship between thermal behavior mechanism depending on characteristics of cooking equipment materials of portable gas ranges. It shows that slope of temperature change curve correlates with difference of heat capacity on thermal behavior characteristics experiment depending on materials of cooking equipment. In conclusion, temperature characteristics appear differently depending on variables such as materials of cooking equipment. Especially, it is necessary to restrict using cooking equipment made of stones, because it is very dangerous that temperature of can is rapidly increasing caused by high heat capacity of stone.

• 한국소음진동공학회논문집
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• 제23권1호
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• pp.3-8
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• 2013

Recently, the impact on hearing induced by using of portable audio equipment have been actively studied. In general, Because they turn the volume up with loud background noise, they may expose to louder noise. In this study, we investigated the maximum noise level of 20 the domestic potable audio equipment and estimated the impact of the hearing induced by portable audio equipment in according to exposure time. As a result, the use of portable audio equipment is assumed to be more three hours when the level of more than 50 % of volume is most likely to affect the hearing.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1272-1277
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• 2004

GPS type portable-alarm-system is composed of satellite receiving equipment, signal transmission equipment, etc. Time errors occur because of the processing methods of the satellite receiving equipment and signal generator, the positional error of GPS itself, etc. With the recent rise of train speed, it becomes very important to secure the stability of portable-alarm-system from time errors, The present study estimated errors caused by the structure of portable-alarm-system, GPS errors. etc., and verified them. In addition, it examined the effects of such errors on portable-alarm-system according to train speed.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 추계학술발표회
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• pp.255-255
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• 2017

• 한국안전학회지
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• 제29권4호
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• pp.42-47
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• 2014

This paper is aimed to investigate and analyze of characteristic for electrical equipment and work environment for the small-scale site. In order to investigate and analyze electrical equipment and work environment for preventing electric shock disaster in construction sites, 50 small-scale construction sites and 12 large-scale construction sites are selected. This paper completed site investigations of low-voltage equipment and the portable electric machine and equipment in 12 large-scale construction sites and 50 small-scale construction sites. The findings were about the electric shock environment relevant to the ground-relevant equipment, the panel board, the protection tools, the sockets, the temporary wiring system, the portable and movable electric machines and equipments in small-scale construction sites. Finally, this study analyzed the domestic and foreign relevant standards and regulations and these findings can be utilized as educational data warning electric shock risk caused by electric equipment in small-scale construction site.

• 전기학회논문지
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• 제67권6호
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• pp.715-723
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• 2018

The energy storage system consists of batteries, power conditioning system and energy management system. If ESS is installed and operated in the field, SAT(Site Acceptance Test) of ESS is being essentially required for the safety and performance of ESS. Furthermore, in order to more accurately and reliably validate the performance of the ESS in advanced countries, it has been required to perform not only performance testing by H/W equipments but also performance verification by S/W tool. Therefore, this paper proposes the modeling of portable test equipment in order to evaluate the performance and reliability of ESS by using the PSCAD/EMTDC S/W. And also, the prototype of 30[kW] scaled portable test equipments is implemented based on the S/W modeling. From the results of various simulations and testings such as power quality, LVRT and anti-islanding tests, it is confirmed that 30[kW] scaled portable test equipment is useful for SAT of ESS, because the simulation results of PSCAD/EMTDC are identical to them of 30[kW] test equipment at the same test conditions.

• 대한방사선기술학회지:방사선기술과학
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• 제41권5호
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• pp.445-450
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• 2018

We aim to evaluate safety of radiation by measuring leakage dose and patient(phantom) incident dose of ZEN-PX II dental portable equipment developed by G company. Measurement for leakage dose of equipment is conducted on the top, at the bottom, on the left, on the right and at the back. Dose measurement incident on the subject with the area dosimeter when using the phantom and measurement the leakage dose of equipment when using the phantom are evaluated. Comparing the right with the highest leakage dose as a 0 cm, 25 cm, 50 cm, 75 cm and 100 cm dose measurement at the measurement height of 100 cm, 64.2 uR was reduced to 47.3 uR in the senser mode 0.32sec. Even in film mode it was measured at 414.4 uR and about 27% lower at 162.6 uR. As the result of this study, when the irradiation time is 2 sec the right side dose is 290.5 uR and sensor mode is 0.32 sec the right side dose is 64.2 uR.