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A conceptual design study for a steady-state Korean fusion demonstration reactor (K-DEMO) was initiated in 2012. The superconducting magnet system is one of the key components of the K-DEMO and the preliminary study on superconducting magnet system has been done in 2015. The superconducting magnet system of K-DEMO consists of 16 TF (Toroidal Field), 8 CS (Central Solenoid) and 12 PF (Poloidal Field) coils. All of the TF, CS and PF coils use internally-cooled Cable-In-Conduit Conductors (CICC). A high performance Nb3Sn-based conductor, an ITER-type Nb3Sn and NbTi conductor will be used for the magnet. Based on the preliminary design, continuous design study is being performed and the K-DEMO magnet system has been evolved mainly for solving engineering issues. Two issues were considered for the TF, the reinforcement of the low field TF CICC structure and the fabrication stability of the high field TF CICC. In the CS magnet, reducing the number of Helium feed-throughs was a main issue. A small change has been made for the PF magnets for keeping a void fraction of the PF conductor. In this work, the major parameters and design updates of the K-DEMO magnet system is presented. [ABSTRACT FROM AUTHOR]

Abstract: The conceptual design of the purpose-built assembly tools required for ITER tokamak assembly is given. The ITER machine assembly is sub-divided into five major activities: lower cryostat, sector sub-assembly, sector assembly, ex-vessel, and in-vessel . The core components, vacuum vessel (VV) and toroidal field coil (TFC), are assembled from nine 40° sub-assemblies, each comprising a 40° VV sector, two TFCs, and the associated VV thermal shield (VVTS). The lower cryostat activities must be completed prior to sector assembly in pit to prepare the foundations for the core components, and to locate the lower components to be trapped once the core components installation begins. In-vessel and ex-vessel activities follow completion of sector assembly. To perform these assembly activities requires both massive, purpose-built tools, and standard heavy handling and support tools. The tools have the capability of supporting and adjusting the largest of the ITER components; with maximum linear dimension 19m and mass 1200tonne, with a precision in the low mm range. Conceptual designs for these tools have been elaborated with the collaboration of the Korean Domestic Agency (KO DA). The structural analysis was performed as well using ANSYS code. [Copyright &y& Elsevier]

The thermal design of a breeding blanket for the Korean Fusion DEMOnstration reactor (K-DEMO) is evaluated using the Multidimensional Analysis of Reactor Safety (MARS-KS) code in this study. The MARS-KS code has advantages in simulating transient two-phase flow over computational fluid dynamics (CFD) codes. In order to confirm the prediction capability of the code for the present blanket system, the calculation results were compared with the CFD prediction. The results of MARS-KS calculation and CFD prediction are in good agreement. Afterwards, a transient simulation for a conceptual problem was carried out so as to show the applicability of MARS-KS for a transient or accident condition. Finally, a methodology to simulate the multiple blanket modules is proposed. [ABSTRACT FROM AUTHOR]

As the ITER is being constructed, there is a growing anticipation for an earlier realization of fusion energy. A major design philosophy for the initiated conceptual design study for a steady-state Korean fusion demonstration reactor (K-DEMO) is engineering feasibility. A two-staged development plan is envisaged. K-DEMO is designed not only to demonstrate a net electricity generation and a self-sustained tritium cycle, but also to be used, in its initial stage, as a component test facility. Then, in its second stage, a major upgrade is carried out by replacing in-vessel components in order to show a net electricity generation on the order of 500 MWe. After a thorough 0-D system analysis, the major radius and minor radius are chosen to be 6.8 m and 2.1 m, respectively. In order to minimize wave deflection, a top-launch high frequency (>200 GHz) electron cyclotron current drive (ECCD) system will be the key system for the current profile control. For matching the high frequency ECCD, a high toroidal field (TF) is required and can be achieved by using high current density Nb 3 Sn superconducting conductor. The peak magnetic field reaches to 16 T with the magnetic field at the plasma center above 7 T. Key features of the K-DEMO magnet system include the use of two TF coil winding packs, each of a different conductor design, to reduce the construction cost and save the space for the magnet structure material. [ABSTRACT FROM AUTHOR]

Abstract: A conceptual design study for a steady-state Korean fusion DEMO reactor (K-DEMO) has been initiated. Two peculiar features need to be noted. First, the major radius is designed to be just below 6.5m, considering practical engineering feasibilities. But still, high magnetic field at the plasma center around 8T is expected to be achieved by using current state-of-the-art high performance Nb3Sn strand technology. Second, a two-stage development plan is being considered. In the first stage, K-DEMO will demonstrate a net electricity generation but will also act as a component test facility. Then, after a major upgrade, K-DEMO is expected to show a net electric generation on the order of 300MWe and the competitiveness in cost of electricity (COE). Feasibility of such a practical, near-future demonstration reactor is studied in this paper, based on a zero dimensional system analysis code study. It was shown that a net electric generation on the order of 300MWe can be achieved below the optimistic β N limit of 5. The elongation of K-DEMO is around 1.8 with single null configuration. Detailed optimization process and the resultant various plasma parameters are described. [Copyright &y& Elsevier]