• Title/Summary/Keyword: tolerable risk

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Quantitative Risk Reduction Model according to SIL allocated by Risk Graph for Railway Platform Door System (Risk Graph에 의해 할당된 SIL에 따른 철도 승강장 도어 시스템의 정량적 Risk 저감 모델)

  • Song, Ki Tae;Lee, Sung Ill
    • Journal of the Korean Society of Safety
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    • v.31 no.5
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    • pp.141-148
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    • 2016
  • There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. Especially, in case of the SIL allocation method without determining of quantitative tolerable risk, the additional review is needed to check whether it is suitable or not is required. In this study, the quantitative risk reduction model based on the safety integrity allocation results of railway platform screen door system using Risk Graph method has been examined in order to review the suitability of quantitative risk reduction according to allocated safety integrity level.

A Study on Establishing Target Reliability Levels for Flammable Gas Transmission Pipelines (가연성가스 수송배관에 대한 목표 신뢰도 수준 설정에 관한 연구)

  • Lee, Jin-Han;Jo, Young-Do;Moon, Jong-Sam
    • Journal of the Korean Institute of Gas
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    • v.22 no.6
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    • pp.52-58
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    • 2018
  • In reliability based design and assessment (RBDA) methodology, reliability targets are used to ensure that safety levels are met relevant limit states in the stage of design and maintenance. The target reliability for flammable gas pipelines have not been developed yet in Korea. Instead of the reliability targets, the tolerable criteria for risk measures such as societal and individual risk have been applied in pipeline risk management. This paper introduces the procedures to develop the target reliability using tolerable risk criteria for societal and individual risk which can be enforced for high pressure natural gas pipelines in quantitative risk assessment. In addition, we propose the target reliability for natural gas and hydrogen gas transmission pipelines by the procedures.

Distribution and Potential Human Risk Assessment of Trace Metals in Benthic Fish Collected from the Offshore of Busan, Korea (부산 연근해 저서어류 체내의 미량금속 분포 특성과 잠재적 인체 위해성 평가)

  • Choi, Jin Young;Kim, Kyoungrean
    • Journal of Korean Society of Environmental Engineers
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    • v.37 no.6
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    • pp.349-356
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    • 2015
  • Trace metals concentrations in the tissue of edible marine fish (4 species), olive flounder (Paralichthys olivaceus), Korean rockfish (Sebastes schlegelii), file fish (Stephanolepis cirrhifer) and abbysal searobin (Lepidotrigla abyssalis), collected near the Yongho wharf in Busan were determined to assess the potential human health risk (HRA) of trace metals by fish consumption. Levels of Li, Cr, Ni, Cu, Zn, As, Cd, and Pb in the fish tissue were $0.005{\pm}0.009$, $0.77{\pm}0.30$, $0.29{\pm}0.34$, $0.49{\pm}0.14$, $15.96{\pm}2.52$, $10.62{\pm}4.67$, $0.001{\pm}0.002$, and $0.045{\pm}0.06mg/kgdw$ respectively. The estimated daily intakes of Cu and Zn and the estimated weekly intakes of As, Cd, and Pb from the fish collected near the Yongho wharf were 0.0032, 0.054-0.18% of PMTDI (provisional maximum tolerable daily intake) and 13, 0.0041, 0.020% of PTWI (provisional tolerable weekly intake) which were set to evaluate the food safeties by the JFCFA (The Joint FAO/WHO Expert Committee on Food Additives). Lifetime cancer risk and target hazard for local residents due to those fish consumption were found to be negligible.

A Study on the Risk Assessment for Works on/near Operating Line (열차운행선 지장공사에 대한 위험도 평가 연구)

  • Jung, Do-Hyun;Wang, Jong-Bae;Lee, Su-Ryong
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1515-1524
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    • 2008
  • In this study, railway accidents from constructing or maintaining works on/near operating line were reviewed during 2005-2007 years. Causes and hazards analysis of these accidents was performed to make an accident scenario for risk assessments. And the risk of worker casualty on/near operating line was quantitatively assessed. Also a constitution method of Risk Matrix for manage tolerable risk level was proposed.

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Iodine Intake and Tolerable Upper Intake Level of Iodine for Koreans (한국인의 요오드 섭취와 요오드 상한섭취량)

  • Lee, Hyun-Sook;Min, Hye-Sun
    • Journal of Nutrition and Health
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    • v.44 no.1
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    • pp.82-91
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    • 2011
  • The present study reviewed the effects of excess iodine intake on thyroid function and the incidence of thyroid disease and discussed the scientific basis for establishing a tolerable upper intake level (UL) of iodine for Koreans. ULs are defined as "the highest level of daily nutrient intake that is likely to pose no risk of adverse effects to almost all individuals in the general population." Koreans consume excess iodine from seaweed, and iodine intake is strongly influenced by seaweed consumption. However, no dose-response data derived from subjects consuming excess iodine frequently but not continuously during a lifetime are available. Therefore, the Korean DRI committee set the iodine UL to reduce the risk of adverse health effects by excess iodine intake for Koreans with distinctive seaweed-eating habits.

Simultaneous Analysis of Mycotoxins and Risk Assessment in Seeds using LC-MS/MS (LC-MS/MS를 이용한 종자류 생약의 곰팡이독소 동시분석 및 위해도 평가)

  • Choi, Eun Jung;Park, Young Ae;Choi, Su Jeong;Jung, Sam Ju;Park, Youn Sun;Hwang, In Sook;Yu, In Sil;Shin, Gi Young
    • Korean Journal of Pharmacognosy
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    • v.51 no.4
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    • pp.270-277
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    • 2020
  • This study analyzed mycotoxins, aflatoxin B1, B2, G1, G2, fumonisin B1, B2, ochratoxin A and zearalenone, using LC-MS/MS and conducted risk assessment on 54 samples of seeds distributed in SeoulYangnyeongsi and the management status of extramural herbal dispensary facility. The matched calibration showed a good linearity as observed in 6 concentration levels(r2>0.999) as a result of method validation applied with Arecae semen. Limits of detection(LOD) and quantification(LOQ) were in the range of 0.02-0.11 ㎍/kg and 0.08-0.34 ㎍/kg, respectively. Recoveries also estimated, ranging from 65.1-99.7% with relative standard deviation(RSD) 0.5-6.3%. As a result of the method on 54 samples, mycotoxins were detected in 16 samples. Among them, two Thujae semen showed a degree of concentration that exceeded the aflatoxin specification. In the risk assessment, the human exposure safety standard values were calculated as ADI(Acceptable Daily Intake) for aflatoxin B1, fumonisin and zearalenone. Ochratoxin A was calculated as PTWI(Provisional Tolerable Weekly Intake). The MOE(Margine of Exposure) of aflatoxin B1 was in the range of 40.36-3536.88. And no items exceeded 100% in %TDI(Tolerable Daily Intake) and %TWI(Tolerable Weekly Intake) of fumonisin, zearalenone and ochratoxin A.

Allocation of Safety Integrity Level for Railway Platform Screen Door System considering Semi-Quantitative Risk Reduction Factor (반 정량적 리스크 저감 요소를 고려한 철도 승강장 스크린 도어시스템의 안전 무결성 수준 할당)

  • Song, Ki Tae;Lee, Sung Ill
    • Journal of the Korean Society of Safety
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    • v.31 no.4
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    • pp.156-163
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    • 2016
  • There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, the theoretical and practical study for safety integrity level is barely under way in the domestic railway industry. This research studied not only the global process of SIL allocation to guarantee safety in accordance with international standards for safety related equipment and system, but the quantitative methodology based on international standard and the semi-quantitative methodology as alternative way for SIL allocation. Specifically, the systematic SIL allocation for platform screen door system of railway is studied applying the semi-quantitative methodology in order to save much time and effort compared to quantitative method.

The Implementation of Risk-Based Inspection for the Refinery Plant

  • Choi, Song-Chun
    • Corrosion Science and Technology
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    • v.11 no.2
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    • pp.43-47
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    • 2012
  • Recently, regulatory bodies quite often encourage to adopt risk-based inspection (RBI) and management programs because they can enhance safety simultaneously with deregulation in Korea. RBI is an integrated methodology that factors risk into inspection and maintenance decision making. This paper describes an example of how to use known risk assessment codes (API 580, API 581 BRD) to address such safety analysis requirements for risk management in the refining industry. Specifically, this paper reports the methodology and the results of implementation to the Crude Distillation Unit(CDU) plant of refinery units using the $KGS-RBI^{TM}$ program, developed by the Korea Gas Safety Corporation in reference of API Codes and ASME PC (Post Construction) with a suitable consideration of Korean situation. The results of the risk and reliability assessment using $KGS-RBI^{TM}$ program are useful in determining whether the detected defects are tolerable or required to be repaired. The subsequent decisions are to manage the future inspection, repair and maintenance planning in the risk reduction control.

Establishment of the Korean Tolerable Daily Intake of Bisphenol A Based on Risk Assessments by an Expert Committee

  • Choi, Chan-Woong;Jeong, Ji-Yoon;Hwang, Myung-Sil;Jung, Ki-Kyung;Lee, Kwang-Ho;Lee, Hyo-Min
    • Toxicological Research
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    • v.26 no.4
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    • pp.285-291
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    • 2010
  • Recently, reproductive and neurobehavioral effects of bisphenol A (BPA) have been documented, and thus a review was requested for BPA management direction by the government. Therefore, this study was performed to establish a Korean tolerable daily intake (TDI) for BPA. An expert committee, consisting of specialists in fields such as toxicology, medicine, pharmacology, and statistics, was asked to evaluate BPA health based guidance values (HbGVs). Although many toxicological studies were reviewed to select a point of departure (POD) for TDI, rat and mouse reproductive studies by Tyl et al. (2002, 2006), which were performed according to GLP standards and OECD guidelines, were selected. This POD was the lowest value determined from the most sensitive toxicological test. The POD, a NOAEL of 5 mg/kg bw/day, was selected based on its systemic toxicity as critical effects. An uncertainty factor of 100 including interspecies and intraspecies differences was applied to calculate the TDI. According to the evaluation results, a TDI of BPA for Korean was suggested at 0.05 mg/kg bw/day. In addition, the BPA exposure level based on food consumption by the Korean population was estimated as 1.509 ${\mu}g/kg$ bw/day, and the HI was evaluated at 0.03 when the TDI of 0.05 mg/kg bw/day was applied. This HI value of 0.03 indicated that hazardous effects would not be expected from BPA oral exposures. Although highly uncertain, further studies on low dose neurobehavioral effects of BPA should be performed. In addition, it is recommended that the 'as low as reasonably achievable' (ALARA) principle be applied for BPA exposure from food packaging materials in newborn infants and children.

Lightning Risk Assessment for Structures Lower than 20m High (높이 20미터 미만인 구조물의 낙뢰리스크 평가)

  • Lee, Ju-Chul;Kim, Gi-Hyun;Lee, Young-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.12
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    • pp.21-27
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    • 2012
  • Korean Industrial Standards for lightning protection system complies with IEC standards. However, the standards are applicable only to buildings and structures more than 20 meters in high. Therefore, it is necessary to determine whether lightning protection system should be installed on structures lower than 20 meters high. This paper proposes an efficient method of assessing risk against lightning of structures lower than 20 meters high. The method suggests simplified lightning protection system and provides selecting an appropriate protection level. The suggested method assumes that structure under assessment has no lightning protection system and there is no person around the structure at the moment of lightning stroke. A simplified method of assessing the risk to human within the structure is developed by adopting the general assessment factor. The selection of a protection level is possible by comparing tolerable risk with physical damage risk caused by a direct lightning. Finally, this paper gives ways to establish surge protection measures when a structure with lightning risk is within a radius of 2km from the assessed structure even if this structure requires no lightning protection system.