Russian DEMO-S reactor with continuous plasma burn

A conceptual study of DEMO-S steady state reactor is being carried out in RF. The main goals of the study are aimed at establishing physics and engineering basis and limitations of the reactor. It was assumed that DEMO is a next step after international thermonuclear experimental reactors (ITER) operation, and so conservative assumptions were used in the study based on ITER engineering. A steady state operation mode is recommended with fusion power of 2-3 GW and maximum first wall (FW) neutron load of 3-4 MW m-2. The reactor has to operate in advance plasma mode with high fraction of bootstrap current. The reversed shear regime and operation in H-mode are evaluated. A lifetime of 30-40 MW m-2 is assumed for the DEMO plant, with three to four changes of plasma facing components. The general reactor layout is determined. Two options of breeding blanket with ceramic and liquid lithium breeders are presented, supported by neutronic, thermalhydraulic and mechanical calculations. A conventional type of water or Li cooling divertor targets with maximum heat load of ∼10 MW m-2 was chosen. Heat to electricity conversion schemes are analysed for both helium and liquid metal coolant with net efficiency of 35-40%. Aspects of radioactive waste management are considered