• Title, Summary, Keyword: Fuel assembly

Search Result 560, Processing Time 0.038 seconds

DROP IMPACT ANALYSIS OF PLATE-TYPE FUEL ASSEMBLY IN RESEARCH REACTOR

  • Kim, Hyun-Jung;Yim, Jeong-Sik;Lee, Byung-Ho;Oh, Jae-Yong;Tahk, Young-Wook
    • Nuclear Engineering and Technology
    • /
    • v.46 no.4
    • /
    • pp.529-540
    • /
    • 2014
  • In this research, a drop impact analysis of a fuel assembly in a research reactor is carried out to determine whether the fuel plate integrity is maintained in a drop accident. A fuel assembly drop accident is classified based on where the accident occurs, i.e., inside or outside the reactor, since each occasion results in a different impact load on the fuel assembly. An analysis procedure suitable for each drop situation is systematically established. For an accident occurring outside the reactor, the direct impact of a fuel assembly on the pool bottom is analyzed using implicit and explicit approaches. The effects of the key parameters, such as the impact velocity and structural damping ratios, are also studied. For an accident occurring inside the reactor, the falling fuel assembly may first hit the fixing bar at the upper part of the standing fuel assembly. To confirm the fuel plate integrity, a fracture of the fixing bar should be investigated, since the fixing bar plays a role in protecting the fuel plate from the external impact force. Through such an analysis, the suitability of an impact analysis procedure associated with the drop situation in the research reactor is shown.

Welding Quality Evaluation on the LASER Welding Parts of the Spacer Grid Assembly for PWR Fuel Assembly (경수로 원전연료용 지지격자체의 LASER 용접부위 평가)

  • Song Gi Nam;Yun Gyeong Ho;Gang Heung Seok;Lee Gang Hui;Kim Su Seong
    • Proceedings of the KWS Conference
    • /
    • v.43
    • /
    • pp.67-69
    • /
    • 2004
  • The fuel assemblies as the nuclear fuel for the pressurized water reactor(PWR) are loaded in the reactor core throughout the residence time of three to five years. The spacer grid assembly, which is an interconnected array of slotted grid straps and is welded at the intersections to form an egg crate structure, is one of the main structural components of the fuel assembly. The spacer grid assembly is structurally required to have enough buckling strength under various kinds of lateral load acting on the fuel assembly so as to keep the fuel assembly straight. To meet the requirement, integrity on the spacer grid welding parts should be carefully checked. In this study, welding quality of the spacer grid assembly welded by several welding companies are examined and compared.

  • PDF

Spacer Grid Assembly with Sliding Fuel Rod Support (삽입 및 이동 가능한 연료봉 지지부의 지지격자 형상)

  • Song, Kee-Nam;Lee, Sang-Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.34 no.7
    • /
    • pp.843-850
    • /
    • 2010
  • A spacer grid assembly is one of the most important structural components of the nuclear fuel assembly of a Pressurized Water Reactor (PWR). A primary design requirement is that the fuel rod integrity be maintained by the spacer grid assembly during the operation of the reactor. In this study, we suggested a new spacer grid assembly having a fuel rod support, which is capable of sliding when the fuel rod vibrates due to flow-induced vibrations in the reactor. By adjusting the relative displacement between the fuel rod and its support, the proposed design will help in reducing fuel rod fretting damage.

Load Concentration Factor Analysis of Fuel Assembly Guide Thimble (핵연료집합체 안내관의 하중집중계수 해석)

  • Lee Young-Shin;Jeon Sang-Youn
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.22 no.3
    • /
    • pp.93-100
    • /
    • 2005
  • The top and bottom nozzles of PWR fuel assembly are connected by guide thimbles and an instrumentation tube that are connected with spacer grids. The fuel rods are inserted into the each cell of spacer grids. The loads acting on the fuel assembly are transmitted to the guide thimbles through the flow plate of top nozzle The axial loads applied to the fuel assembly are not equally distributed among the guide thimble due to the geometry of the top nozzle flow plate and spacer grid. In this study, the load concentration factors for the $17\times17$ fuel assembly were calculated. The analytical model fur the calculation of the load concentration factor of top nozzle flow plate was developed using ANSYS 5.6. The finite element analyses were performed using the model composed of top nozzle, guide thimble, and spacer grid. And, the analysis results were compared with the test results.

Flow and Convective Heat Transfer Analysis Using RANS for A Wire-Wrapped Fuel Assembly

  • Ahmad, Imteyaz;Kim, Kwang-Yong
    • Journal of Mechanical Science and Technology
    • /
    • v.20 no.9
    • /
    • pp.1514-1524
    • /
    • 2006
  • This work presents the three-dimensional analysis of flow and heat transfer performed for a wire-wrapped fuel assembly of liquid metal reactor using Reynolds-averaged Wavier-Stokes analysis in conjunction with 557 model as a turbulence closure. The whole fuel assembly has been analyzed for one period of the wire-spacer using periodic boundary conditions at inlet and outlet of the calculation domain. Three different assemblies, two 7-pin wire-spacer fuel assemblies and one bare rod bundle, apart from the pressure drop calculations for a 19-pin case, have been analyzed. Individual as well as a comparative analysis of the flow field and heat transfer have been discussed. Also, discussed is the position of hot spots observed in the wire-spacer fuel assembly. The flow field in the subchannels of a bare rod bundle and a wire-spacer fuel assembly is found to be different. A directional temperature gradient is found to exist in the subchannels of a wire-spacer fuel assembly Local Nusselt number in the subchannels of wire-spacer fuel assemblies is found to vary according to the wire-wrap position while in case of bare rod bundle, it's found to be constant.

Design and Analysis of the Fuel Boost Pump for the Aircraft (항공기용 연료승압펌프 설계)

  • Lee, Jung-hoon;Kim, Joon Tae
    • Journal of Aerospace System Engineering
    • /
    • v.6 no.4
    • /
    • pp.18-23
    • /
    • 2012
  • The fuel boost pump for the aircraft was first indigenously developed in Korea. It is one of the core component for fuel subsystem and composed of motor assembly, impeller assembly, and body assembly with BLDC motor. It shall provide some amount of fuel to engine system continuously for any flight condition considering sudden altitude change and any attitude. This paper describes the procedures and the results for the design, the integration, and the performance analysis of the fuel boost pump.

Welding Quality Evaluation on the LASER Welding Parts of the Spacer Grid Assembly for PWR fuel Assembly (경수로 원전연료용 지지격자의 LASER 용접품질 평가)

  • Song, Gi-Nam;Yun, Jeong-Ho;Gang, Hong-Seok;Lee, Gang-Hui;Kim, U-Gon;Kim, Su-Seong
    • Proceedings of the KWS Conference
    • /
    • /
    • pp.109-111
    • /
    • 2005
  • Nuclear fuel assemblies for pressurized water reactors(PWR) are loaded in the reactor core throughout the residence time of three to five years. A spacer grid assembly, which is an interconnected array of slotted grid straps and is welded at the intersections to form an egg crate structure, is one of the main structural components of the nuclear fuel assembly. The spacer grid assembly is structurally required to have enough buckling strength under various kinds of lateral loads acting on the nuclear fuel assembly so as to keep the nuclear fuel assembly straight. To meet this requirement, it is necessary to weld the welding parts carefully and precisely. In this study, laser welding qualities of the spacer grid assembly welded by several welding companies, such as weld strength, weld penetration depth, and weld bead size, are examined and compared.

  • PDF

Welding Quality Evaluation on the LASER Welding Parts of the Zircaloy Spacer Grid Assembly for PWR Fuel Assembly(II) (경수로 원전연료용 질칼로이 지지격자체의 LASER 용접품질 평가(II))

  • Song, Gi-Nam;Yun, Gyeong-Ho;Lee, Gang-Hui;Kim, Su-Seong;Han, Hyeong-Jun
    • Proceedings of the KWS Conference
    • /
    • /
    • pp.70-72
    • /
    • 2005
  • Nuclear fuel assemblies for pressurized water reactors(PWR) are loaded in the reactor core throughout the residence time of three to five years. A spacer grid assembly, which is an interconnected array of slotted grid straps and is welded at the intersections to form an egg crate structure, is one of the main structural components of the nuclear fuel assembly. The spacer grid assembly is structurally required to have enough buckling strength under various kinds of lateral loads acting on the nuclear fuel assembly so as to keep the nuclear fuel assembly straight. To meet this requirement, it is necessary to weld the welding parts carefully and precisely. In this study, laser welding qualities of the Zircaloy spacer grid assembly welded by two welding companies, such as weld strength, weld penetration depth, and weld bead size, are examined and compared.

  • PDF

An Experimental Study on PWR Nuclear Fuel Assembly Vibration (경수로 핵연료집합체 진동의 실험적 고찰)

  • 장영기;김규태;조규종
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • /
    • pp.82-87
    • /
    • 2003
  • Nuclear fuel with a big slenderness ratio is susceptible to flow-induced vibration under very severe conditions of high temperature, high flow and exposure to irradiation in nuclear reactor. The fuel assembly should, therefore, be designed to escape any resonance due to the vibration during the reactor operation, in particular, in case of the design changes. In addition, the amplitudes due to the grid vibration, the fuel rod vibration and the fuel assembly vibration should be minimized to reduce the grid-to-rod fretting wear. Fuel assembly vibration tests in air at room temperature and in water at high temperature have been performed to investigate fuel vibration behaviors. The frequency and damping during the test in air have been compared to those in water. Through the hydraulic test, the advanced assembly has been evaluated not to be susceptible to any resonance. In addition, the test data from the tests can be used to make fuel model and to evaluate grid-to-rod fretting wear.

  • PDF

Construction and Functional Tests of Fuel Assembly Mechanical Characterization Test Facility (핵연료집합체 기계적특성 시험시설 구축과 기능시험)

  • Lee, Kang-Hee;Kang, Heung-Seok;Yoon, Kyung-Ho;Yang, Jae-Ho
    • Transactions of the Korean Society of Pressure Vessels and Piping
    • /
    • v.12 no.1
    • /
    • pp.11-16
    • /
    • 2016
  • Fuel assembly's mechanical characterization test facility (FAMeCT) in KAERI was constructed with upgraded functional features such as increased loading capacity, underwater vibration testing and severe earthquake simulation for extended fuel design guideline. This facility is designed and developed to provide out-pile fuel data for accident analysis model and fuel licensing. Functional tests of FAMeCT were performed to confirm functionality, structural integrity, and validity of newly-built fuel assembly mechanical test facility. Test program includes signal check of data acquisition system, load delivering capacity using real-sized fuel assemblies and a standard loading cylindrical rigid specimen. Fuel assembly's lateral bending test was carried out up to 30 mm of pull-out displacement. Limit case axial compression loading test up to 33 kN was performed to check structural integrity of UCPS (Upper Core Plate Simulator) support frame. Test results show that all test equipment and measurement system have acceptable range of alignment, signal to noise ratio, load carrying capacity limit without loss of integrity. This paper introduces newly constructed fuel assembly's mechanical test facility and summarizes results of functional test for the mechanical test equipment and data acquisition system.