Gas-cooled high performance divertor for a power plant

Recent US activities on advanced He-cooled W-alloy divertor concepts for fusion power plants

“…An early concept is described in Ref. [1]. A more recent evolution of that concept is described in Ref.…”

“…Based on that evaluation, an advanced concept of a plate divertor employing heat transfer enhancement by either flow in micro-channels or through a pin-array had been proposed by Hermsmeyer and Malang at the ISFNT-6 in San Diego [1]. In this concept, the divertor surface heat flux limit was raised to ∼10 MW/m 2 by flowing the helium through an extremely small gap of 0.1 mm width over a length of ∼10 mm.…”

“…Recently, the Georgia Tech group has focused on variants of the He-cooled flat-plate divertor, a design originally developed at the Karlsruhe Research Center (FZK) [1]. The major advantage of this particular design is the large surface area of each module (2000 cm 2 ), which reduces the number of modules needed to cool the O(100 m 2 ) area of the divertor by more than two orders of magnitude compared with either the T-tube or HEMJ designs, with module surface areas of about 13 cm 2 and 2.5 cm 2 , respectively.…”

“…They range in scale from a plate configuration with characteristic dimension of the order of 1 m [1,2], to the ARIES-CS T-tube configuration with characteristic dimension of the order of 10 cm [3,4], to the EU FZK finger concept with characteristic dimension of the order of 1.5 cm [5,6]. All these designs utilize tungsten or tungsten alloy as structural material, requiring material development to widen their operating temperature range from a low of ∼600-700 • C (governed by W ductility considerations) to enable coupling to an ODS (oxide-dispersion-strengthened) FS (ferritic steel) manifold, to a high of ∼1300 • C (governed by the W re-crystallization limit) to provide desirable high-temperature capability.…”

High heat flux components—Readiness to proceed from near term fusion systems to power plants

“…The proposed concepts range in scale from a plate configuration with characteristic dimension of the order of 1 m [14,15], to the ARIES T-tube configuration with characteristic dimension of the order of 10 cm [12,16], to the EU FZK finger concept with characteristic dimension of the order of 2 cm [17,18]. The trend in moving to smaller-scale units is to minimize the thermal stress under a given heat load; however, this is done at the expense of increasing the number of units (for an example tokamak case, from ~750 to ~110,000 to ~535,000 for the plate, T-tube and finger concepts, respectively) with a corresponding impact on the reliability of the system.…”