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Nam K.O.,National Fusion Research Institute | Park H.K.,National Fusion Research Institute | Kim D.J.,National Fusion Research Institute | Ahn H.J.,National Fusion Research Institute | And 3 more authors.
Fusion Engineering and Design | Year: 2010

The final assembly of main components of the International Thermonuclear Experimental Reactor (ITER) tokamak, Vacuum Vessel (VV) and Toroidal Field Coils (TFCs), is achieved by the sequential assembly of the nine sub-assembled 40° sectors in tokamak pit. Each sub-assembled 40° sector is composed of one VV 40° sector, two TFCs, and in-between Vacuum Vessel Thermal Shield (VVTS) segments. Sub-assembly is carried out in the assembly building and then the sub-assembled sectors are transferred into tokamak pit, in sequence, to complete sector assembly. The role of in-pit assembly tool is to support and align the sub-assembled sectors in tokamak pit. It also plays the role of reference datum during assembly until the completion of main components assembly. Korea Domestic Agency (KO DA) has developed the conceptual design of most ITER purpose-built assembly tools under the collaboration with the ITER Organization. Among the conceptual designs carried out, this paper describes the function, the structure, the selected material and the design results of the in-pit assembly tools comprising central column, radial beams and their supports, TF inner supports and in-pit working floor. The results of structural analysis using ANSYS for the various loading cases are given as well. The resultant stresses and deflections turned out to fall within the allowable ranges. © 2010 Published by Elsevier B.V. All rights reserved.

Park H.K.,National Fusion Research Institute | Nam K.O.,National Fusion Research Institute | Kim D.J.,National Fusion Research Institute | Ahn H.J.,National Fusion Research Institute | And 3 more authors.
Fusion Engineering and Design | Year: 2010

The International Thermanuclear Experimental Reactor (ITER) tokamak device is composed of 9 vacuum vessel (VV)/toroidal field coils (TFCs)/vacuum vessel thermal shields (VVTS) 40° sectors. Each VV/TFCs/VVTS 40° sector is made up of one 40° VV, two 20° TFCs and associated VVTS segments. The 40° sectors are sub-assembled at assembly hall respectively and then nine 40° sectors sub-assembled at assembly hall are finally assembled at tokamak in-pit hall. The assembly strategy and tools for the 40° sector sub-assembly and final assembly should be developed to satisfy the basic assembly requirements of the ITER tokamak device. Accordingly, the purpose-built assembly tools should be designed and manufactured considering assembly plan, available space, cost, safety, easy operation, efficient maintenance, and so on. The 40° sector assembly tools are classified into 2 groups. One group is the sub-assembly tools including upending tool, lifting tool, sub-assembly tool, VV supports and bracing tools used at assembly hall and the other group is the in-pit assembly tools including lifting tool, central column, radial beams and their supports. This paper describes the current status of the assembly strategy and major tools for the VV/TFCs/VVTS 40° sector assembly at in-pit hall and assembly hall. The conceptual design of the major assembly tools and assembly process at assembly hall and tokamak in-pit hall are presented also. © 2010 Published by Elsevier B.V. All rights reserved.

Park T.-G.,ACT Inc. | Choi C.-H.,SFA Engineering Co. | Won J.-H.,Korea Aerospace University | Choi J.-H.,Korea Aerospace University
International Journal of Precision Engineering and Manufacturing | Year: 2010

In the reliability analysis involving fatigue life, statistical information of the geometric parameters and the S-N parameters of the material are necessary to calculate failure probability. Recently, Dimension Reduction Method combined with Kriging approximation (named as K-DR) was developed by the authors, which is an efficient means to construct probability distribution for a response function due to the random input parameters based on the concept of additive decomposition. If all the probability distributions of input parameters are well established in the fatigue life analysis, the K-DR method can be ordinarily employed to obtain PDF of fatigue life. The probability distributions of S-N parameters, however, are not always available due to the limited experimental data. In this case, a family of curves representing confidence bound which is called P-S-N curve are more useful in the design practice. Then the random S-N parameters are turned into a number of deterministic values with different confidence level, at which the PDF's can be obtained respectively by repeated implementation of K-DR method. By exploiting the concept of additiveness, however, the repetition of K-DR can be avoided, i.e., once an ordinary problem under the random S-N parameters is solved using the K-DR, comparable accuracy can be achieved without implementing new K-DR for the additional problems at each of the deterministic S-N parameters. The proposed method is demonstrated for the fatigue design problem of knuckle. The resulting information is of great practical value and will be very helpful for the design engineers in making decision in the fatigue design process. © KSPE and Springer 2010.

Nam K.,National Fusion Research Institute | Kim D.,National Fusion Research Institute | Park H.,National Fusion Research Institute | Ahn H.,National Fusion Research Institute | And 4 more authors.
Fusion Engineering and Design | Year: 2014

The ITER toroidal field coils (TFCs) are connected by 3 different connecting structures as follows; Outer Intercoil Structure (OIS), Inner Intercoil Structure (IIS), Intermediate Outer Intercoil Structure (IOIS). In assessing the assembly, requirements and environmental conditions of each Intercoil structure, the IOIS and IIS assembly were thought to be the most challenging compared to the OIS assembly due to the very limited assembly space available and the strict requirements requested by IO, especially the IOIS assembly, which has particularly difficult installation requirements including complicated shear pin assemblies. A conceptual and preliminary design has been developed by the Korean domestic agency (KODA) for the sub assembly and final assembly phase; the tool includes the ability to control both IOIS plates simultaneously. For design verification of the IOIS assembly tool mentioned above, structural analysis has been carried out considering seismic event. Also, a half sized mock-up has been fabricated and tested according to assembly procedures. In this paper, a description of tool design and the results of analysis and mock-test will be introduced. © 2014 Elsevier B.V.

Kang D.K.,National Fusion Research Institute | Kim R.G.,CoTec Inc. | Nam K.,National Fusion Research Institute | Noh C.H.,National Fusion Research Institute | And 4 more authors.
Fusion Engineering and Design | Year: 2016

This paper describes both the test results of the bath type silver coating and the design of the bath to construct the silver coating plant for ITER thermal shield. The tests of small specimens made of SS304L and SS304LN were carried out to investigate the effect of the nitrogen content in SS304LN on the silver coating quality. The effect of different degreasing agents was also investigated to improve silver coating process. Small mock-up was tested to find a proper dipping direction during the electroplating process. Finally, noble bath design was conceived and structurally validated. Overall layout of silver coating plant is also shown in this paper. © 2016 Elsevier B.V.

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