• Title/Summary/Keyword: psaA

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Multi-unit Level 3 probabilistic safety assessment: Approaches and their application to a six-unit nuclear power plant site

  • Kim, Sung-yeop;Jung, Yong Hun;Han, Sang Hoon;Han, Seok-Jung;Lim, Ho-Gon
    • Nuclear Engineering and Technology
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    • v.50 no.8
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    • pp.1246-1254
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    • 2018
  • The importance of performing Level 3 probabilistic safety assessments (PSA) along with a general interest in assessing multi-unit risk has been sharply increasing after the Fukushima Daiichi nuclear power plant (NPP) accident. However, relatively few studies on multi-unit Level 3 PSA have been performed to date, reflecting limited scenarios of multi-unit accidents with higher priority. The major difficulty to carry out a multi-unit Level 3 PSA lies in the exponentially increasing number of multi-unit accident combinations, as different source terms can be released from each NPP unit; indeed, building consequence models for the astronomical number of accident scenarios is simply impractical. In this study, a new approach has been developed that employs the look-up table method to cover every multi-unit accident scenario. Consequence results for each scenario can be found on the table, established with a practical amount of effort, and can be matched to the frequency of the scenario. Preliminary application to a six-unit NPP site was carried out, where it was found that the difference between full-coverage and cut-off cases could be considerably high and therefore influence the total risk. Additional studies should be performed to fine tune the details and overcome the limitations of the approach.

Control validation of Peugeot 3∞8 HYbrid4 Vehicle Using a Reduced-scale Power HIL Simulation

  • Letrouve, Tony;Lhomme, Walter;Bouscayrol, Alain;Dollinger, Nicolas
    • Journal of Electrical Engineering and Technology
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    • v.8 no.5
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    • pp.1227-1233
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    • 2013
  • The new engineering challenges lead to a control of a vehicle more and more complex. To tackle this issue, Hardware-In-the-Loop (HIL) simulation is used in the development of real-time embedded systems. In this paper, the control of a double parallel hybrid vehicle is validated using a reduced power HIL simulation. A graphical description is used in order to organize the emulation and control. Some experimental results of a versatile testbed are given for the Peugeot $3{\infty}8$ HYbrid4.

Production of High Purity Oxygen by Conbination of Membrane and PSA Methods

  • Hwang, Sun-Tak
    • Proceedings of the Membrane Society of Korea Conference
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    • 1994.03a
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    • pp.1-21
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    • 1994
  • There are growing needs to produce relatively high purity (99.0% or higher) oxygen at low cost. For small scale production, both pressure swing adsorption (PSA) and membrane process are competitve and less expensive or more convient than well known crygenic fractionation technology. A continuous membrane colume (CMC) combined with a PSA oxygen generator can be employed to produce high purity oxygen continuosly. The oxygen-enriched gas generated by a PSA unit, with a concentration of 93-94%, is fed to the CMC that consists of three modules of poly(imide) hollow fibers. Several experiments were conducted by varying parameters, such feed flow rate, transmenbrane pressure drop, stage cut, and feed location in order to obtain a high oxygen concentration above 99.0%. A two-series unit mode was also employed with CMC operation to optimize the given membrane area.

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An Integrated Approach of Component Reliability Data on Korea Standard Nuclear Power Plants Using PRinS (원전 신뢰도 DB 시스템을 이용한 표준형 원전 통합 기기 신뢰도 데이터 분석 및 적용)

  • Jeon, Ho-Jun;Hwang, Seok-Won;Chi, Moon-Gu
    • Journal of the Korean Society of Safety
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    • v.26 no.6
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    • pp.85-89
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    • 2011
  • Component reliability data were analyzed by using PRinS(Plant Reliability data information System) based on the latest operating experiences of eight KSNPs(Korea Standard Nuclear Power plants), and these new data were applied to the KSNP PSA models. In addition, the existing PSA models were revised for reflecting as-built and as-operated plant conditions. As a result of newly performing PSA in this paper, CDF and LERF were estimated 26.1% and 18.2% lower than the existing values, respectively. It was identified that the risk measures decreased not because of revising the models but because of applying the new component reliability data. The result and the method of this paper could be used when generating plant specific data and performing the living PSA in the future.

D-PSA-K: A Model for Estimating the Accumulated Potential Damage on Kiwifruit Canes Caused by Bacterial Canker during the Growing and Overwintering Seasons

  • Do, Ki Seok;Chung, Bong Nam;Joa, Jae Ho
    • The Plant Pathology Journal
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    • v.32 no.6
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    • pp.537-544
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    • 2016
  • We developed a model, termed D-PSA-K, to estimate the accumulated potential damage on kiwifruit canes caused by bacterial canker during the growing and overwintering seasons. The model consisted of three parts including estimation of the amount of necrotic lesion in a non-frozen environment, the rate of necrosis increase in a freezing environment during the overwintering season, and the amount of necrotic lesion on kiwifruit canes caused by bacterial canker during the overwintering and growing seasons. We evaluated the model's accuracy by comparing the observed maximum disease incidence on kiwifruit canes against the damage estimated using weather and disease data collected at Wando during 1994-1997 and at Seogwipo during 2014-2015. For the Hayward cultivar, D-PSA-K estimated the accumulated damage as approximately nine times the observed maximum disease incidence. For the Hort16A cultivar, the accumulated damage estimated by D-PSA-K was high when the observed disease incidence was high. D-PSA-K could assist kiwifruit growers in selecting optimal sites for kiwifruit cultivation and establishing improved production plans by predicting the loss in kiwifruit production due to bacterial canker, using past weather or future climate change data.

Internal Event Level 1 Probabilistic Safety Assessment for Korea Research Reactor (국내 연구용원자로 전출력 내부사건 1단계 확률론적안전성평가)

  • Lee, Yoon-Hwan;Jang, Seung-Cheol
    • Journal of the Korean Society of Safety
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    • v.36 no.3
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    • pp.66-73
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    • 2021
  • This report documents the results of an at-power internal events Level 1 Probabilistic Safety Assessment (PSA) for a Korea research reactor (KRR). The aim of the study is to determine the accident sequences, construct an internal level 1 PSA model, and estimate the core damage frequency (CDF). The accident quantification is performed using the AIMS-PSA software version 1.2c along with a fault tree reliability evaluation expert (FTREX) quantification engine. The KRR PSA model is quantified using a cut-off value of 1.0E-15/yr to eliminate the non-effective minimal cut sets (MCSs). The final result indicates a point estimate of 4.55E-06/yr for the overall CDF attributable to internal initiating events in the core damage state for the KRR. Loss of Electric Power (LOEP) is the predominant contributor to the total CDF via a single initiating event (3.68E-6/yr), providing 80.9% of the CDF. The second largest contributor is the beam tube loss of coolant accident (LOCA), which accounts for 9.9% (4.49E-07/yr) of the CDF.

Prostate Cancer Screening in a Healthy Population Cohort in Eastern Nepal: an Explanatory Trial Study

  • Belbase, Narayan Prasad;Agrawal, Chandra Shekhar;Pokharel, Paras Kumar;Agrawal, Sudha;Lamsal, Madhab;Shakya, Vikal Chandra
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.2835-2838
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    • 2013
  • Background: Prostate cancer features a substantial incidence and mortality burden, similarly to breast cancer, and it ranks among the top ten specific causes of death in males. Objective: To explore the situation of prostate cancer in a healthy population cohort in Eastern Nepal. Materials and Methods: This study was conducted in the Department of General Surgery at B. P. Koirala Institute of Health Sciences, Dharan, Nepal from July 2010 to June 2011. Males above 50 years visiting the Surgical Outpatient Department in BPKIHS were enrolled in the study and screening camps were organized in four Teaching District Hospitals of BPKIHS, all in Eastern Nepal. Digital rectal examination (DRE) was conducted by trained professionals after collecting blood for assessment of serum prostatic specific antigen (PSA). Trucut biopsies were performed for all individuals with abnormal PSA/DRE findings. Results: A total of 1,521 males more than 50 years of age were assessed and screened after meeting the inclusion criteria. The vast majority of individuals, 1,452 (96.2%), had PSA ${\leq}4.0$ ng/ml. Abnormal PSA (>4 ng/ml) was found in 58 (3.8%). Abnormal DRE was found in 26 (1.72%). DRE and PSA were both abnormal in 26 (1.72%) individuals. On the basis of raised PSA or abnormal DRE 58 (3.84%) individuals were subjected to digitally guided trucut biopsy. Biopsy report revealed benign prostatic hyperplasia in 47 (3.11%) and adenocarcinoma prostate in 11 (0.73%). The specificity of DRE was 66.0%with a sensitivity of 90.9% and a positive predictive value of 38.5%. The sensitivity of PSA more than 4ng/ml in detecting carcinoma prostate was 100% and the positive predictive value for serum PSA was 19.0% Conclusions: The overall cancer detection rate in this study was 0.73% and those detected were locally advanced. Larger community-based studies are highly warranted specially among high-risk groups.

A Study on the Correlations between Total Prostate Volume and Prostate Transition Zone Volume Assessed Using Blood and Ultrasound Tests: in the Healthy Korean Men in Thirties (혈액, 초음파 검사 결과를 이용한 전립선이행대용적의 상관관계 연구: 기초질환이 없는 30대를 대상으로)

  • Kim, Sang-Hyun
    • Journal of the Korean Society of Radiology
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    • v.11 no.5
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    • pp.407-412
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    • 2017
  • This study investigates the correlations between the total prostate volume (TPV), using the prostate specific antigen (PSA) and prostate specific antigen density (PSAD) as the blood test results and transrectal ultrasound (TRUS), and the prostate transition zone volume (PTZV), as well as variables such as age; the findings can be used as clinical indicators. A retrospective analysis was conducted on 68 healthy men in their 30s who underwent TRUS and PSA and PSAD blood tests from June 2007 to April 2016, with no history of treatment in their prostate. Siemens Acuson sequoia 512 and the probe Siemens EC-10C5 Endocavitary were used as the ultrasound equipment. For statistical analysis, SPSS 18.0 was used to calculate the standard deviation and mean of each variable; Pearson's correlation analysis was also performed. The descriptive statistics of the variables were $24.27{\pm}6.60$ for TPV, $6.99{\pm}6.60$ for PTZV, $2.12{\pm}2.76$ for PSA, and $0.281{\pm}0.1$ for PSAD. The coefficients of correlations between PTZV and variables were 0.831 for PSAD, 0.707 for TPV, 0.398 for age, and 0.118 for PSA. While PSA and age were positively correlated, PSAD and TPV were highly correlated. Therefore, PTZV of men in their 30s without underlying diseases can be predicted using PSAD and TPV.