A Korean fusion energy development promotion law (FEDPL) was enacted in 2007. As a following step, a conceptual design study for a steady-state Korean fusion demonstration reactor (K-DEMO) was initiated in 2012. After the thorough 0D system analysis, the parameters of the main machine characterized by the major and minor radii of 6.8 and 2.1 m, respectively, were chosen for further study. The analyses of heating and current drives were performed for the development of the plasma operation scenarios. Preliminary results on lower hybrid and neutral beam current drive are included herein. A high performance Nb3Sn-based superconducting conductor is adopted, providing a peak magnetic field approaching 16 T with the magnetic field at the plasma centre above 7 T. Pressurized water is the prominent choice for the main coolant of K-DEMO when the balance of plant development details is considered. The blanket system adopts a ceramic pebble type breeder. Considering plasma performance, a double-null divertor is the reference configuration choice of K-DEMO. For a high availability operation, K-DEMO incorporates a design with vertical maintenance. A design concept for K-DEMO is presented together with the preliminary design parameters.

KSTAR has demonstrated divertor heat flux broadening during edge-localized-mode (ELM)-crash-suppression using ITER-like 3-row resonant magnetic perturbation (RMP) for the first time. To address a couple of critical issues in ITER RMP, robust ELM-crash-suppression methodology has been explored at low q95 and established in KSTAR using low-n RMPs. Taking full advantage of the ITER-like 3-row in-vessel control coils (IVCC) in KSTAR, a set of intentionally misaligned RMP configurations (IMC) was tested to investigate whether or not IMC could be compatible with ELM-crashsuppression, while minimizing electromagnetic loads on RMP coils. As a result, the ITER-like 3-row IMCs were found not only to have been compatible with the ELM-crash-suppression, but also to have broadened the heat flux in the vicinity of the outer strike point on divertor. In comparison, the 2-row RMPs have rarely affected the near scrape-off-layer (SOL) heat flux despite slightly broadened profile change in the far-SOL. Since the divertor heat flux broadening reflects the dispersal of the peaked near-SOL heat flux, the experimental outcome is quite favorable to the ITER choice of 3-rows, instead of 2-rows. Nonetheless, since the IMC-driven broadening observed in the attached plasmas in KSTAR might appear substantially different in the partially detached plasmas in ITER, additional investigation has been conducted to see if RMP-driven, ELMcrash-suppression could be compatible with detached plasmas. Although no detached plasmas have been identified with ELM-crash-suppression yet, significantly reduced divertor heat flux was confirmed in high density, ELM-crash-suppressed plasmas at q95=3.8 using n=2 RMPs. These new findings elevate the confidence level about the ITER RMP system, while the remaining uncertainties need to be further clarified using the 3-row IVCCs in KSTAR. As long as mode-locking percussion is minimized along with a quick recovery of wall conditions, the access to the targeted q95 (~ 3) for ITER is foreseen to be feasible in KSTAR.

We present calculations of heating and current drive by neutral injection and by electromagnetic waves in the ion cyclotron, helicon, lower hybrid, and electron cyclotron frequency ranges for the steady state burn conditions in a K-DEMO configuration with I p = 12.3 MA, a = 2.1 m, R o = 6.8 m, B o = 7.4 T, n e = 1.1 × 10 20 m −3 , T(0) = 40 keV, and Z eff = 1.5. Lower hybrid wave current drive calculations comprise a 2D scan over poloidal launcher location and launched n , at a fixed frequency of 5 GHz. An ICRF frequency scan over 50-100 MHz is based on an ITER-like ICRF midplane antenna; the absorption calculation includes thermal D, T, He, Ar, and W as well as suprathermal beam ions and alphas. Helicon fast wave performance is surveyed by varying frequency over 0.6-2.5 GHz, launched n from −1.6 to −3, and launcher position from top to bottom on the low-field side. An ITER-like 1 MeV neutral beam system with quasi-tangential geometry is scanned over elevation to vary the targeted minor radius. The electron cyclotron survey varies the frequency (190-300 GHz), launcher poloidal location, and the poloidal and toroidal direction of the launched waves. We report for each system the range of minor radius in which current is driven, the current drive efficiency, the optimal system parameters, and typical profiles of driven current. Electron and ion heating profiles are reported for the ICRF and NBI systems.

The 1st International workshop on Environmental, Safety and Economic Aspects of Fusion Power (ESEFP) was held on 13 September 2015 at Jeju Island, South Korea. The workshop was initiated by the International Energy Agency Implementing Agreement on a Co-operative Program on ESEFP. The workshop was well attended with about forty participants representing twelve institutions in ten countries. The presentations covered safety issues and environmental impacts, availability improvement and risk control and socio-economic aspects of fusion power. Safety and licensing gaps between DEMO and ITER were discussed in depth with the consensus output presented as a plenary presentation at the 12th International Symposium on Fusion Nuclear Technology (ISFNT-12). The next workshop is planned to be held in conjunction with the ISFNT-13 in 2017.

-K-DEMO is being studied by South Korean researchers as a follow-on to ITER and the next step toward the construction of a commercial fusion power plant. The K-DEMO mission defines a staged approach targeting operation with an initial testing phase for plasma facing components and critical operating systems to be followed by a second phase which centers on upgrading the in-vessel components for operation at 200 to 600 MWe with a planned 70% availability. This paper reviews the general arrangement of the K-DEMO device core, the novel configuration concept for the vertical maintenance of large in-vessel segments and describes the arrangement and maintenance of planned interfacing auxiliary systems and services -design features which impact the ability to operate with a staged mission strategy that ends with high availability operations.