• Title/Summary/Keyword: impact range

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A study on the effect of material impurity concentration on radioactive waste levels for plans for decommissioning of nuclear power plant

  • Gilyong Cha;Minhye Lee;Soonyoung Kim;Minchul Kim;Hyunmin Kim
    • Nuclear Engineering and Technology
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    • v.55 no.7
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    • pp.2489-2497
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    • 2023
  • Co and Eu impurities in the SSCs are nuclides that dominantly influence the neutron-induced radioactive inventory in metal and concrete radwastes (radioactive wastes) during NPP decommission. The impurity concentrations provided by NUREG/CR-3474 were used for the practical range of Co and Eu impurity concentrations to be applied to the code calculations. Metal structures near the core were evaluated to be ILW (intermediate-level waste) for the whole range of Co impurity concentration, so the boundary line between ILW and LLW (low-level waste) has no change for the whole concentration range provided by NUREG/CR-3474. Also, the boundary line between VLLW (very low-level waste) and CW (clearance waste) in the concrete shield could alter a little depending on the Eu impurity concentration within the range provided by NUREG/CR-3474. From this work, it is found that the concentration of material impurities of SSCs gives no critical impact on determining radwaste levels.

Home Range and Daily Activity of Nutria(Myocastorcoypus) Using Radio Tracking in South Korea (원격무선추적을 이용한 한국 정착 뉴트리아(Myocastor coypus)의 행동권 및 활동성 연구)

  • Kim, Areum;Kim, Young-Chae;Lee, Do-Hun
    • Journal of Environmental Impact Assessment
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    • v.29 no.3
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    • pp.182-197
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    • 2020
  • This study investigated the home range and characteristics of activities to contribute to the improvement of management techniques and the successful promotion of management policies of invasive nutria, which is a representative invasive species of South Korea. Six individuals were captivated for the study. Remote radio tracking on three of them was carried out followed by the analysis of the results. The average home range of the follow-up individuals were confirmed to be 0.043 ㎢ at MCP 95%, 0.085 ㎢ at K 95%. It was 0.018 ㎢ at K 50%, which is the core space. In 95% MCP, males exhibited the home range with 0.058 ㎢, showed wider home range 0.046 ㎢ than females who showed 0.012 ㎢, and showed a wider home range 0.015 ㎢ more at night than during the day. As a result of comparing the results of this study with the case studies of overseas studies, it is determined that the magnitude of the derived home range is the result of a stable habitat in which the procurement of food resources is smooth and human interference is limited. The daily moved distance of males was larger than that of females, with a maximum moved distance of 1,278 m per day. Activity at the study site is high from around sunset to around 6 A.M., 10 P.M., 7 P.M., 1 A.M., and 5 A.M., and high around sunrise and low during the daytime such as 2 P.M., which reflected the propensity of nocturnal animals to act. The results of this study on the home range and activity in nutria can be used as useful data forimproving the management of invasive alien species for the installation and operation of traps, the spatial setting of controlled areas, and the calculation of the amount ofresources together with a basic understanding of nutria's behaviors in South Korea.

Vibrational Characteristics of the Gas Pipelines Conveying Flow (유체가 흐르는 가스파이프의 진동 특성)

  • Kim, Kyung-Tae;Lee, Sung-Soo;Lee, Seong-Woo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.2
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    • pp.337-343
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    • 2012
  • This work investigates the vibrational characteristics of the underground gas pipelines. Experiments were conducted to analyze the effects of various parameters on the vibrational characteristics from the emergency detection point of view. Influences of the various types of impact exerted on the pipe, height of free fall and measuring locations were analyzed. Especially, the difference between the vibrational signal generated by the direct impact on the pipe and the ambient noise was successfully identified. To validate the experimental observation, computer simulation was also performed with constant properties(elasticity, fluid velocity and internal pressure) which are directly conjectured from the accompanying experiment with a real pipe system.

Towards Understanding the Value of a Loyal Customer in Electronic Commerce: An Expectation-Disconfirmation Theory (전자상거래에서 충성고객 가치에 대한 이해: 기대 불일치 이론을 중심으로)

  • Coo, Chulmo;Koh, Chang E.;Lee, Dae Yong;Lee, Cheong-Ho
    • Knowledge Management Research
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    • v.9 no.2
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    • pp.129-146
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    • 2008
  • Customers' evaluation of Website with satisfaction is critical in electroniccommerce. Previous research has studied in a distinct approach; especially IT oriented constructs-perceived usefulness, easy of use and marketing oriented constructs-product, shopping experience, service quality. Despite those important previous studies regarding the usage and the purchase of goods and services, how consumers are satisfied and why consumers leave Web sites without purchasing have not been extensively researched. This study explored those determinants of consumer satisfaction with Web site using expectation-disconfirmation theory (EDT). The present paper extends the range of EDT from antecedents of expectation to consequence of satisfaction. The result suggests that experience and familiarity has an impact on expectation as well as perceived performance and satisfaction. Second, higher expectation makes a negative impact on disconfirmation of expectation. Third, positive disconfirmation of expectation makes a positive impact on satisfaction. Forth. satisfaction produces loyalty and repurchasing intention. Finally, loyal customer has stronger intention to repurchase than satisfied customer.

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A Study on Numerical Perforation Analysis of Axisymmetric Bullet by the Particle Method (입자법을 이용한 축대칭 탄자의 관통거동 수치해석 연구)

  • Kim, Yong-Seok;Kim, Yong-Hwan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.6
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    • pp.164-171
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    • 2008
  • A modified generalized particle algorithm, MGPA, was suggested to improve the computational efficiency of standard SPH method in numerical analysis of high speed impact behavior. This method uses a numerical failure mechanism than material failure models to describe the target penetration. MGPA algorithm was more effective to describe the impact phenomena and new boundaries produced during the calculation process were well recognized and treated in the target penetration problem of a bullet. When bullet perforation problems were analyzed by this method, MGPA algorithm calculation gives the stable numerical solution and stress oscillation or particle penetration phenomena were not shown. The error range in ballistic velocity limit is less than $2{\sim}13%$ for various target thickness.

Average Particle Size Prediction of Rubber Dispersed Phase in High Impact Polystyrene (내충격성 폴리스티렌의 고무상 입자경 예측)

  • Lee, Seong-Jae;Chung, Kyung-Ho
    • Elastomers and Composites
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    • v.31 no.5
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    • pp.327-334
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    • 1996
  • A correlative analysis has been carried out to predict the average particle size of rubber dispersed phase In high impact polystyrene manufactured by bulk polymerization. To do the correlation, a mechanistic model suggested previously by the author was used for describing the size of stabilizing particles agitated under the turbulent viscous shear subranges in a prepolymerization reactor, where the rubber particles were assumed to be formed at the time of phase inversion in the reactor. Viscosities required for the model were postulated to describe the overall behavior of butadiene rubber and polystyrene mixture along the wide range of conversion. The good agreement between the model and the experimental data from a plant was quite satisfactory for the prediction of the average rubber particle size of high impact polystyrene.

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Implementation of automatic mode for remote impact wrench task (로보트를 이용한 원격조작 임팩트렌치 작업의 자동수행 기능부 구현)

  • 박영수;박병석;이재설
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.832-837
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    • 1991
  • After many years of proliferation, the nuclear industry is indebted for a formidable consequence, the safe management of spent fuel. Naturally, the high radioactivity involved with such process motivates the development of effective telerobotic systems. Nevertheless, the existing master-slave type of tele manipulators are limited in effectiveness by the human operator's limited sensory and manipulation capabilities. This paper presents the result of a research effort to resolve such problems by assigning the slave manipulator a certain degree of intelligence; sensing and actuation. In the presented system, a perception-action loop is achieved using ultrasonic range sensor and laser distance sensor interfaced with the PUMA 760 industrial robot system, and applied to automating impact wrenching task for unbolting the lid of nuclear spent fuel cask. The perception-action loop performs determination of the cask location, collision avoidance and centering of the impact wrench onto the bolt head. To aid the insertion task and to provide versatility a mounting module consisting of an RCC device and an automatic tool changer is designed and implemented. The performance of the developed system is tested on the model cask and the result is given.

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SPH Parameters for Analysis of Penetration Phenomenon at Hypervelocity Impact of Meteorite (운석의 초고속 충돌 관통현상 해석을 위한 SPH 매개변수)

  • Lee, Sung-Soo;Seo, Song-Won;Min, Oak-Key
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.10
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    • pp.1738-1747
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    • 2003
  • Smoothed Particle Hydrodynamics (SPH), a pure Lagrangian numerical method, is applied to analysis of penetration phenomenon of bumper plate which is installed outside of spacecraft hull to protect the spacecraft against hypervelocity meteorite impact. Effects of SPH parameters, such as artificial viscosities, smoothing lengths, numbers of particles and time increments, are analysed by comparing the SPH simulation results with experimental ones with regard to subsequent formation of debris cloud. An optimum range of parameter values is determined by error analysis and various SPH numerical results are compared with experiments.

The Development of 20 mm Test Barrel with Replaceable Powder Chamber Type (약실교환방식의 20 mm 시험용 총열 개발)

  • Lee, Jin-Sung;Lee, Young-Shin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.4
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    • pp.630-638
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    • 2011
  • A new smooth bore test barrel was developed to be used in sensitivity assessment test for explosives and fragment impact test. The bore diameter of the barrel is 20 mm, and the powder chamber is designed to be replaceable with the 12.7 mm, 20 mm and 30 mm type chamber. The test results showed the wide range of fragment velocity from 400 to 2000 m/s, included the fragment velocity requirement of the fragment impact test(alternate procedure #1) in MIL-STD-2105B. The stability of the bullet trajectory was checked by test shots and the structural safety of the system has been confirmed through the stress analysis and the interior ballistics analysis of the barrel.

Climate Data Qualification for Water Quality Impact Assessment (수질영향평가의 신뢰수준 향상을 위한 기상자료의 검정)

  • Lee, Khil-Ha;Cho, Hongyeon
    • Journal of Environmental Impact Assessment
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    • v.20 no.5
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    • pp.601-613
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    • 2011
  • This study is focused on a climate data integrity to improve water quality assessment due to the social development projects. The study is in an attempt to calculate both extreme ranges of weather data measurements and partly provide means to assess qualification of data which fall within the extremes at the 23 meteorological weather stations. Generally speaking, maximum temperature, minimum temperature, relative humidity, dew point temperature are in the range of reasonable accuracy. However, there found some outliers of the brightness sunshine hours in Cheonan station. Also some years in Gwangju, Seoul, Wonju, Busan, and Jeju never reach to their upper limit and perhaps the calibration of the equipment is doubtful. The users need to take cautions in using the brightness sunshine hour data in preparation of water resources planning and management by estimating evapotranspiration and river discharge, and/or growth rate of the algae (phytoplankton).