Compact DEMO, SlimCS: design progress and issues

Abstract

The design progress in a compact low aspect ratio (low A) DEMO reactor, ‘SlimCS’, and its design issues are reported. The design study focused mainly on the torus configuration including the blanket, divertor, materials and maintenance scheme. For continuity with the Japanese ITER-TBM, the blanket is based on a water-cooled solid breeder blanket. For vertical stability of the elongated plasma and high beta access, the blanket is segmented into replaceable and permanent blankets and a sector-wide conducting shell is arranged inbetween these blankets. A numerical calculation indicates that fuel self-sufficiency can be satisfied when the blanket interior is ideally fabricated. An allowable heat load to the divertor plate should be 8 MW m−2 or lower, which can be a critical constraint for determining a handling power of DEMO.

Plasma surface interactions in impurity seeded plasmas

“…ITER itself will heavily rely on impurity seeding, at least during its nuclear phase with high power discharges and a tungsten divertor. A future reactor will have to radiate several hundreds of megawatts [14] [15], and power exhaust is one of the major design issues.…”

Direct extrapolation of radial profile data to a self-ignited fusion reactor based on the gyro-Bohm model

“…In designing fusion reactors [1][2][3][4][5], the temperature and density profiles have been artificially determined by designers. In spite of the strict constraints enforced by MHD equilibrium and transport physics, there still is a large degree of freedom in determining the profiles.…”

Nuclear analysis of DEMO water-cooled blanket based on sub-critical water condition

“…In line with the reactor design, the DEMO blanket design was conducted [2]. For continuity with the Japanese ITER-TBM, the blanket was based on water-cooled solid breeders [3,4]. Presently, the blanket design was now underway to achieve sufficiently high tritium breeding ratio (TBR) [5] (Fig.…”