Corrosion and activation in fusion cooling loops—TRACT

Abstract

TRansport and ACTivation simulates the flow and isotope transport inside a network of 1-D channels. The code handles liquid or gaseous coolants encountered in fusion devices. The physical model comprises fluid flow (pressure drop, flow and pumping power), mass transfer ( corrosion) and radioactive decay ( activation) in irradiation conditions. Solubility dictates precipitation and/or crud formation and deposition. TRACT is written in the IDL language with a graphical user interface. The parameters are provided by the u ser. A network is the combination of channel configuration and circulating fluid and parameters comprise pipes joining at n odes. The network topology, size-metrics and materials of channels are free, to construct an arbitrary network. The layout can be in 3-D space (elevation with gravity included), allowing for breaks and disconnected loops. An example case for IFMIF demonstrates the layout loop, its components (fittings, cooler, tank, target, 3-D elevation), flow, pumping power and corrosion, dissolution, precipitation and deposition of material. Calculations show the target flow velocity at 20.4 m/s, the cooler and pump pressure drop at 4.75 and 19.3 kPa, respectively, the pump power needed to circulate the lithium coolant at 2.5 kW, and the net positive suction head (pump inlet) at 40 kPa. The average corrosion, dissolution and deposition, normalised to solid density at about 16 months, are 34, 29 and 29 μ m, respectively. The dissolution is 4.192 × 1 0 − 9 kg/m 2s, and the masses released 66 kg and deposited 34 kg. The code is capable, and was developed, to be used for a general purpose cooling loop of any fusion components.