Estimation of the Pumping Power of the Liquid Metal Divertor REVOLVER-D for the LHD-Type Helical Fusion Reactor FFHR-d1

Abstract

The required pumping power for the liquid metal ergodic limiter/divertor REVOLVER-D (Reactor-oriented Effectively VOLumetric VERtical Divertor), which is considered as an optional divertor design for the LHDtype helical fusion reactor FFHR-d1, has been estimated with a consideration of the change in the strength of transverse magnetic field along the flow channel. It is found that the pressure drop and the required pumping power can be suppressed to an acceptable level by using insulated ducts.

Overview of Fusion Engineering Research in Japan Focusing on Activities in NIFS and Universities

“…Fundamental studies have been carried out such as thermofluid of the free surface flow in a magnetic field 80 and deuterium transport under plasma exposure 81 . Helical Reactor Design in NIFS adopted a liquid divertor option 82 . Experimental verification of the concept is being carried out 83 .…”

Conceptual design of a liquid metal limiter/divertor system for the FFHR-d1

“…This figure is obtained by assuming a flow velocity at the shower of 5 m/s and a constant mass flow rate of ~3,600 ton/h along the channel. The pressure loss and pump power under this condition have been evaluated [43]. In Ref.…”

“…In Ref. 43, the flow velocity of the shower jets was assumed to be ~3.7 m/s, while other conditions, e.g., the flow path, the inner diameter and the length of ducts, etc., were identical to those shown in Fig. 10.…”

“…10. Therefore, we have reevaluated the case with 5 m/s of the shower jet velocity using the same procedure used in [43]. In the case of v = 5 m/s, the total pressure loss is ~0.85 MPa, in which the MHD loss is ~0.17 MPa, and the total pump power needed to circulate molten tin at all 10 sections is ~14.4 MW.…”

Maintainability of the helical reactor FFHR-c1 equipped with the liquid metal divertor and cartridge-type blankets

“…For example, the High-Temperature Superconducting (HTS) magnets, the Liquid Metal (LM) divertor, and the toroidally segmented Molten Salt (MS) blanket are adopted in the challenging option. Typical candidates for the LM divertor and the cartridge-type MS blanket are the REVOLVER-D (Reactor-oriented Effectively VOLumetric VERtical Divertor) [5,6] and the CARDISTRY-B (CARtridges Divided and InSerTed RadiallY -Blanket) [7], respectively.…”