• Title/Summary/Keyword: Risk-Informed

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Radiological Risk Assessment for the Public Under the Loss of Medium and Large Sources Using Bayesian Methodology (베이지안 기법에 의거한 중대형 방사선원의 분실 시 일반인에 대한 방사선 위험도의 평가)

  • Kim, Joo-Yeon;Jang, Han-Ki;Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.30 no.2
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    • pp.91-97
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    • 2005
  • Bayesian methodology is appropriated for use in PRA because subjective knowledges as well as objective data are applied to assessment. In this study, radiological risk based on Bayesian methodology is assessed for the loss of source in field radiography. The exposure scenario for the lost source presented in U.S. NRC is reconstructed by considering the domestic situation and Bayes theorem is applied to updating of failure probabilities of safety functions. In case of updating of failure probabilities, it shows that 5 % Bayes credible intervals using Jeffreys prior distribution are lower than ones using vague prior distribution. It is noted that Jeffreys prior distribution is appropriated in risk assessment for systems having very low failure probabilities. And, it shows that the mean of the expected annual dose for the public based on Bayesian methodology is higher than the dose based on classical methodology because the means of the updated probabilities are higher than classical probabilities. The database for radiological risk assessment are sparse in domestic. It summarizes that Bayesian methodology can be applied as an useful alternative lot risk assessment and the study on risk assessment will be contributed to risk-informed regulation in the field of radiation safety.

Identification of Wells Effect and Effects of Risk Perception of Wrong Verdict (평결 판단에서 웰스효과의 확인과 평결 오류 위험성 지각의 영향)

  • Dong-Heon Seok;Mi-Jin Kim
    • Korean Journal of Culture and Social Issue
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    • v.19 no.2
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    • pp.159-178
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    • 2013
  • The purpose of this study was to 1) replicate the Wells effect(i.e., reluctance to rule against the Defendant solely on the basis of probabilistic evidence) in Korea and 2) examine the validity of an Alternative explanation(i.e., perception of risk of wrong verdict). In study 1(n=46), mock jurors in the tire-tracks condition were reluctant to rule against the defendant based on their perceived probability and this pattern was not resulted in the tire-tracks-belief condition. Therefore, the Wells effect was replicated in Korea. In study 2(n=70), we manipulated the participants' perception of risk of wrong verdict. That is, participants who were assigned in the high risk perception of wrong verdict were informed that if the defendant were found guilty, the defendant would get considerable demage both in finance and reputation of the company. Participants in the low risk perception of wrong verdict condition were informed that these demage would not be great. The results revealed that the Wells effect was pronounced in the high risk perception of wrong verdict condition. That is, participants were more reluctant to rule against the defendant when they perceive the significance of the result of wrong verdict as high. Limitations of the study and the directions for future study were discussed.

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Information Sources for Serbian Women on Cervical Carcinoma Risk Factors

  • Dugandzija, Tihomir;Mikov, Marica Miladinov;Rajcevic, Smiljana;Kacavenda, Dragana;Malenkovic, Goran;Ristic, Mioljub
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.6
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    • pp.2931-2934
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    • 2012
  • Background: The epidemiological situation regarding cervical carcinoma in Serbia is rather unfavorable and one of contributing factors is the insufficient interest of women concerning the risk factors responsible for occurrence of this disease. The aim of this study was to determine the sources of relevant information for women Methods: An anonymous questionnaire was used for questioning of patients, students and women undergoing systematic examinations. There were 600 women in total in 2006, 2009 and 2010, and the data were statistically processed by the ${\chi}^2$ test with Yates correction and the Fisher test. Results: When observed for certain groups of tested women, and summed up for all three periods, there was a statistically significant difference for the answer "without any knowledge" (p=0.0001). When observed for certain years and summed up for all three tested groups, there was a statistically significant difference in answers regarding the source of information, the "doctor" (p=0.0011), "media" (p=0.0349) and "encyclopedia-internet" (p=0.0136). Conclusion: The media are a dominant source of information for women on risk factors for cervical cancer. The significance of the Internet increased during the three observed periods, while the students considered themselves least informed of all concerning risk factors.

Risk Assessment for Abolition of Gross Containment Leak Monitoring System Test in CANDU Design Plant (중수로 원자로건물 총누설감시계통 시험 중지에 따른 리스크 영향 평가)

  • Bae, Yeon-Kyoung;Na, Jang-Hwan;Bahng, Ki-In
    • Journal of the Korean Society of Safety
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    • v.30 no.5
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    • pp.123-130
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    • 2015
  • Wolsong Unit 2,3&4 has been performing a containment integrity test during power operation. This test could impact to the safe operation during test. If an accident occurs during pressure dropping phase, reactor trip can be delayed because of the increased pressure difference which causes a time delay to reach the trip set-point. On the contrary, if an accident occurs during pressure increasing phase, reactor trip could be accelerated because the pressure difference to the trip set-point decrease. Point Lepreau nuclear power plant, which installed GCLMS (Gross Containment Leakage Monitoring System) in 1990, has discontinued the test since 1992 due to these adverse effects. Therefore, we evaluated the risk to obviate the GCLMS test based on PWR's ILRT (Integrated Leak Rate Test) extension methodologies. The results demonstrate that risk increase rate is not high in case of performing only ILRT test at every 5 years instead of doing GCLMS test at every 1.5 years. In addition, the result shows that GCLMS test can be removed on a risk-informed perspective since risk increasement is in acceptable area of regulatory acceptance criteria.

A Study of Subclinical Thyroid Function Disorder and the Risk of Coronary Heart Disease in Women (여성의 무증상 갑상샘 기능이상과 관상동맥질환 발생과의 관련성 연구)

  • Yeoum, Soon-Gyo;Park, Chai-Soon
    • Korean Journal of Adult Nursing
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    • v.22 no.1
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    • pp.80-89
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    • 2010
  • Purpose: This paper has attempted to investigate the association between the subclinical thyroid function disorder caused by natural change in thyroid hormones or thyroid remedies and the incidence of CHD. Methods: Data was analyzed of 7,675 women who had undergone health examinations in a hospital in Gyeonggi-do between January 2007 and December 2008. The covariation of the coronary risk factors such as age, BMI, HbA1C, systolic blood pressure, LDL:HDL-cholesterol ratio, CRP, smoking and exercise were analyzed by using logistic regression analysis. Results: A significant increase in serum TSH was observed with higher age (F=26.91, p=.00). In terms of age, the risk of CHD started to gradually increase since the 40s and sharply since the 60s (${\chi}^2$=113.29, p=.00). The serum TSH was the most significant parameter influencing CHD (B=.12, p=.00). The risk of coronary heart disease was 3.12 times higher in the subclinical hypothyroidism group (OR=3.12) while no significant difference was observed in the subclinical hyperthyroidism group. Conclusion: Subclinical hypothyroidism may be an independent risk factors for CHD. A nurse nursing patients with thyroid disorder should be well informed of their state of subclinical thyroid function disorder and make efforts to extend their health expectancy.

A Qualitative Study on Consumers' Perceptions of Food Safety Risk Factors (식품안전 위해요인에 대한 소비자 인식 : 질적연구를 통한 접근)

  • Yoon, YeoYm;Kim, Kyungja
    • Journal of Families and Better Life
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    • v.31 no.4
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    • pp.15-31
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    • 2013
  • Consumers are quite worried about food safety because food is one of the most important necessities in everyday life. Many studies have been conducted regarding the food safety issues, however, most researches have focused only on a limited range of risk factors and used only quantitative survey methods. The purpose of this study was to investigate consumers' perceptions of the risky components of food safety and how the perceptions have been formed. For this study in-depth interviews were conducted. For the interviewees, nine housewives, who are in their 30s to 50s, were selected taking into consideration their age, education level, number of children, and employment status. Results showed that the risk factors many consumers worried about were agricultural pesticides, MSG, food additives, GMO, Mad Cow Disease, preservatives, and growth hormones, etc. Consumers were worried about the risk of the retail process the most because they thought it was not informed and controlled well. Consumers tend to worry much more when the risks are involuntary, uncontrollable, unreliable, and have a gradual negative effect. Some of the food safety-oriented behaviors of consumers were also investigated.

Human Reliability Analysis for Risk Assessment of Nuclear Power Plants (원자력발전소 위험도 평가를 위한 인간신뢰도분석)

  • Jung, Won-Dea;Kim, Jae-Whan
    • Journal of the Ergonomics Society of Korea
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    • v.30 no.1
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    • pp.55-64
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    • 2011
  • Objective: The aim of this paper is to introduce the activities and research trends of human reliability analysis including brief summary about contents and methods of the analysis. Background: Various approaches and methods have been suggested and used to assess human reliability in field of risk assessment of nuclear power plants. However, it has noticed that there is high uncertainty in human reliability analysis which results in a major bottleneck for risk-informed activities of nuclear power plants. Method: First and second generation methods of human reliability analysis are reviewed and a few representative methods are discussed from the risk assessment perspective. The strength and weakness of each method is also examined from the viewpoint of reliability analyst as a user. In addition, new research trends in this field are briefly summarized. Results: Human reliability analysis has become an important tool to support not only risk assessment but also system design of a centralized complex system. Conclusion: Human reliability analysis should be improved by active cooperation with researchers in field of human factors. Application: The trends of human reliability analysis explained in this paper will help researchers to find interest topics to which they could contribute.

A New Approach to Selection of Inspection Items using Risk Insight of Probabilistic Safety Assessment for Nuclear Power Plants

  • Park, Younwon;Kim, Hyungjin;Lim, Jihan;Choi, Seongsoo
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.14 no.2
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    • pp.49-58
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    • 2018
  • The regulatory periodic inspection program (PSI) conducted at every overhaul period is the most important process for confirming the safety of nuclear power plants. The PSI for operating nuclear power plants in Korea mainly consist of component level performance check that had been developed based on deterministic approach putting the same degree of importance to all the inspection items. This inspection methodology is likely to be effective for preoperational inspection. However, once the plant is put into service, the PSI must be focused on whether to minimize the risk of accident using defense-in-depth concept and risk insight. The incorporation of defense-in-depth concept and risk insight into the deterministic based safety inspection has not been well studied so far. In this study, two track approaches are proposed to make sure that core damage be avoided: one is to secure success path and the other to block the failure path in a specific event tree of PSA. The investigation shows how to select safety important components and how to set up inspection group to ensure that core damage would not occur for a given initiating event, which results in strengthening defense-in-depth level 3.

Compliance with Screening Recommendations According to Breast Cancer Risk Levels in Izmir, Turkey

  • Acikgoz, Ayla;Ergor, Gul
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.1737-1742
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    • 2013
  • Early diagnosis has a major role in improving prognosis of breast cancer. The purpose of this study was to assess the risk status of women 35-69 years of age using risk assessment models and the prevalence of mammography in a community setting. The sample of this cross sectional study consisted of 227 women, 35-69 years of age residing in Izmir, a city located in western region of Turkey. A questionnaire was used to collect data and the Gail and Cuzick-Tyrer models were applied to assess the risk of breast cancer. In this study, 52.7% of women had mammography at least once, and 41.3% of the women over the age of 40 had mammography screening in the last two years. The five years risk for breast cancer was high in 15.8% of women according to the Gail model and ten years risk was high in 21.7% with the Cuzick-Tyrer model. In the present study, the breast cancer risk levels were assessed in a population setting for the first time in Turkey using breast cancer risk level assessment models. Being in 60-69 age group, having low education and not being in menopause were significant risk factors for not having mammography according to logistic regression analysis. Mammography utilization rate was low. Women must be educated about breast cancer screening methods and early diagnosis. The women in the high risk group should be informed on their risk status which may increase their attendance at breast cancer screening.

Evaluation of Cholangiocarcinoma Risk and its Related Factors In Wetland Geographical Communities of Ubon Ratchathani, Thailand

  • Songserm, Nopparat;Woradet, Somkiattiyos;Bureelerd, Onanong;Charoenbut, Pattaraporn
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.1811-1815
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    • 2016
  • Wetland geographical areas have a higher incidence of Opisthorchis viverrini-associated cholangiocarcinoma (CCA), confirmed by data from geographic information systems, than other areas. Behavioral data also indicate that people in these areas traditionally eat uncooked freshwater fish dishes, a vehicle for O. viverrini infection. The best approach to reducing CCA incidence is decreasing risk factors together with behavior alteration. Evaluation of CCA risk and its related factors are first needed for planning the prevention and control programs in the future. We therefore aimed to evaluate the CCA risk and explore its related factors among people in wetland communities of Ubon Ratchathani, Thailand. A cross-sectional study was conducted between July and August 2014. In total 906 participants, with informed consent, completed questionnaires. Overall risk of CCA was determined by multiplying odds ratios (ORs) of the risk factors for CCA from literature reviews. A mean score of 5.95 was applied as the cut-off point. Assessment of factors related to overall risk of CCA was accomplished using conditional logistic regression. Of all participants, 60.15% had a high level of the overall risk of CCA. Factors related to the overall risk of CCA were gender (p<0.001), marital status (p<0.001), perceived susceptibility (p=0.043) and prevention behavior for CCA (p<0.001). In conclusion, most participants in this community had a high level of overall risk of CCA. Therefore, integrated prevention and control programs continue to be urgently required.