• Title/Summary/Keyword: reactors

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Online training and education from the VR-1 reactor-Lessons learned

  • Ondrej Novak;Tomas Bily;Ondrej Huml;Lubomir Sklenka;Filip Fejt;Jan Rataj
    • Nuclear Engineering and Technology
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    • v.55 no.12
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    • pp.4465-4471
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    • 2023
  • Hands-on education and training is a key part of fixing and developing technology knowledge and is an inherent part of many engineering and scientific curricula. However, access to large complex training facilities, such as nuclear reactor, could be limited by various factors, such as unavailability of those facilities in the region, high traveling costs or harmonization of the schedules of hands-on E&T with theoretical lectures and with the operational schedule of the facility. To handle the issue, several success stories have been reached with the introduction of the Internet Reactor Labs (IRL). The Internet Reactor Labs can strongly contribute to accessibility of training at research reactors and can contribute to improvements in their utilization. The paper describes the development of the Internet Reactor Lab at the VR-1 reactor of the Czech Technical University in Prague. Contrary to single-purpose IRLs, it presents various modalities of online teaching and training in experimental reactor physics and reactor operation in general as well as outreach activities that have been developed in recent years.

OECD/NEA STUDY ON THE ECONOMICS AND MARKET OF SMALL REACTORS

  • Lokhov, Alexey;Cameron, Ron;Sozoniuk, Vladislav
    • Nuclear Engineering and Technology
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    • v.45 no.6
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    • pp.701-706
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    • 2013
  • According to the OECD/NEA estimates, nuclear power plants (NPPs), whether with a large reactor or with small modular reactors (SMRs), are competitive with many other electricity generation technologies in a significant number of cases, one of the exceptions being natural gas in the USA with the current level of prices. However, SMRs have particular features and requirements setting conditions for their deployment. This paper presents the preliminary analysis by OECD/NEA of the economics, opportunities, and market for small nuclear reactors.

Effect of Mechanical Mixing Intenstiy on Composting (교반강도가 퇴비화에 미치는 영향)

  • Hwang, Seon-Suk;Hwang, Eui-Young;Namkoong, Wan
    • Journal of the Korea Organic Resources Recycling Association
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    • v.3 no.2
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    • pp.47-57
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    • 1995
  • The purpose of this study was to investigate the effect of mechanical mixing intensity on composting. The major parameters investigated were the mixing intensity and initial moisture content. Laboratory scale composting reactors with mixing equipment were used in this study. Wastes used for the study were raw nightsoil sludge, nightsoil sludge after vacuum evaporation treatment and pig manure. When moisture contents were 60% and 63%, amount of organic material degraded in the continuous mixing reactors was higher than that in the intermittent mixing reactors. Compost produced from reactors with continuous mixing had better texture than that obtained from reactors with intermittent mixing. When moisture content was 68%, organic waste was kneaded rather than mixed in the continuous mixing reactors. Amount of organic material degraded in the continuous mixing reactors also was lower than that in the intermittent mixing reactors.

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Quench Characteristics of Superconducting Elements using Reactors at Series and Parallel Connections (직·병렬연결시 리액터를 이용한 초전도 소자의 퀜치 특성)

  • Choi, Hyo-Sang;Lim, Sung-Hun;Cho, Yong-Sun;Nam, Gueng-Hyun;Lee, Na-young;Park, Hyoung-Min
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.9
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    • pp.863-869
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    • 2005
  • We investigated quench characteristics of superconducting elements connected in series and parallel each other. The serial and parallel connections of superconducting elements causes a difficulty in simultaneous quench due to slight difference between their critical current densities. In other to induce simultaneous quench, we fabricated four type circuits; serially connected circuit before parallel connection, the circuit connected in parallel before serial connection, serially connected circuit before parallel connection with reactors, the circuit connected in Parallel before serial connection with reactors. We confirmed that the simultaneous quenches occurred in serial and parallel connections of superconducting elements using reactors. In addition, the power burden of superconducting elements was smaller than those of serial and parallel connections of superconducting elements without reactors.

Development of RETRAN-03/MOV Code for Thermal-Hydraulic Analysis of Nuclear Reactor Under Mowing Conditions

  • Kim, Jae-Hak;Park, Good-Cherl
    • Nuclear Engineering and Technology
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    • v.28 no.6
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    • pp.542-550
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    • 1996
  • Nuclear ship reactors have several features different from land-based PWR's. Especially, effects of ship motions on reactor thermal-hydraulics and good load following capability for abrupt load changes are essential characteristics of nuclear ship reactors. This study modified the RETRAN-03 to analyze the thermal-hydraulic transients under three-dimensional ship motions, named RETRAN-03/MOV in order to apply to future marine reactors. First Japanese nuclear ship MUTSU reactor have been analyzed under various ship motions to verify this code. Calculations have been peformed under rolling, heaving and stationary inclination conditions during normal operation. Also, the natural circulation has been analyzed, which can provide the decay heat removal to ensure the passive safety of marine reactors. As results, typical thermal-hydraulic characteristics of marine reactors such as flow rate oscillations and S/G water level oscillations have been successfully simulated at various conditions.

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Safety Classification of Systems, Structures, and Components for Pool-Type Research Reactors

  • Kim, Tae-Ryong
    • Nuclear Engineering and Technology
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    • v.48 no.4
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    • pp.1015-1021
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    • 2016
  • Structures, systems, and components (SSCs) important to safety of nuclear facilities shall be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions. Although SSC classification guidelines for nuclear power plants have been well established and applied, those for research reactors have been only recently established by the International Atomic Energy Agency (IAEA). Korea has operated a pool-type research reactor (the High Flux Advanced Neutron Application Reactor) and has recently exported another pool-type reactor (Jordan Research and Training Reactor), which is being built in Jordan. Korea also has a plan to build one more pool-type reactor, the Kijang Research Reactor, in Kijang, Busan. The safety classification of SSCs for pool-type research reactors is proposed in this paper based on the IAEA methodology. The proposal recommends that the SSCs of pool-type research reactors be categorized and classified on basis of their safety functions and safety significance. Because the SSCs in pool-type research reactors are not the pressure-retaining components, codes and standards for design of the SSCs following the safety classification can be selected in a graded approach.

A negative reactivity feedback driven by induced buoyancy after a temperature transient in lead-cooled fast reactors

  • Arias, Francisco J.
    • Nuclear Engineering and Technology
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    • v.50 no.1
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    • pp.80-87
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    • 2018
  • Consideration is given to the possibility to use changes in buoyancy as a negative reactivity feedback mechanism during temperature transients in heavy liquid metal fast reactors. It is shown that by the proper use of heavy pellets in the fuel elements, fuel rods could be endowed with a passive self-ejection mechanism and then with a negative feedback. A first estimate of the feasibility of the mechanism is calculated by using a simplified geometry and model. If in addition, a neutron poison pellet is introduced at the bottom of the fuel, then when the fuel element is displaced upward by buoyancy force, the reactivity will be reduced not only by disassembly of the core but also by introducing the neutron poison from the bottom. The use of induced buoyancy opens up the possibility of introducing greater amounts of actinides into the core, as well as providing a palliative solution to the problem of positive coolant temperature reactivity coefficients that could be featured by the heavy liquid metal fast reactors.

Analysis on Current Limiting and Recovery Characteristics of a SFCL Dependent on Magnetic Coupling of Shunt Reactors (션트리액터의 자기결합유무에 따른 초전도전류제한기의 전류제한 및 회복특성 분석)

  • Lim, Sung-Hun;Ahn, Jae-Min;Kim, Jin-Seok;Moon, Jong-Fil;Kim, Jae-Chul
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.10a
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    • pp.277-279
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    • 2008
  • The current limiting and recovery characteristics of a superconducting fault current limiter (SFCL) using shunt reactors were analyzed. Generally, the shunt reactor has a role to distribute the even voltage drop between high-Tc superconducting (HTSC) elements comprising the SFCL. However, the shunt reactors magnetically separated was not contributed to the equal voltage distribution between the HTSC elements. Through the experiments for the SFCL with both the magnetically coupled and magnetically uncoupled shunt reactors, the magnetically coupled shunt reactors were confirmed to improve the current limiting and recovery characteristics of the SFCL.

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CORE DESIGN CONCEPTS FOR HIGH PERFORMANCE LIGHT WATER REACTORS

  • Schulenberg, T.;Starflinger, J.
    • Nuclear Engineering and Technology
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    • v.39 no.4
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    • pp.249-256
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    • 2007
  • Light water reactors operated under supercritical pressure conditions have been selected as one of the promising future reactor concepts to be studied by the Generation IV International Forum. Whereas the steam cycle of such reactors can be derived from modem fossil fired power plants, the reactor itself, and in particular the reactor core, still need to be developed. Different core design concepts shall be described here to outline the strategy. A first option for near future applications is a pressurized water reactor with $380^{\circ}C$ core exit temperature, having a closed primary loop and achieving 2% pts. higher net efficiency and 24% higher specific turbine power than latest pressurized water reactors. More efficiency and turbine power can be gained from core exit temperatures around $500^{\circ}C$, which require a multi step heat up process in the core with intermediate coolant mixing, achieving up to 44% net efficiency. The paper summarizes different core and assembly design approaches which have been studied recently for such High Performance Light Water Reactors.