The conceptual design of the subcritical advanced burner reactor (SABR), a 3000-MW(thermal) annular, modular sodium pool–type fast reactor, fueled by metallic transuranic (TRU) fuel processed from discharged light water reactor fuel and driven by a tokamak D-T fusion neutron source based on ITER physics and technology, has been substantially upgraded. Several issues related to the integration of fission and fusion technologies have been addressed, e.g., refueling a modular sodium pool reactor located within the magnetic coil configuration of a tokamak, achieving long-burn quasi-steady-state plasma operation, access for heating and current drive power transmission to a toroidal plasma surrounded by a sodium pool fast reactor, suppression of magnetohydrodynamic effects in a liquid metal coolant flowing in a magnetic field, tritium self-sufficiency in a TRU transmutation reactor, shielding the superconducting magnets from fusion and fission neutrons, etc. A design concept for a SABR that could be deployed within 25 years, based on the IFR/PRISM metal-fuel, sodium pool fast reactor technology and on the ITER fusion physics and technology, is presented. This design concept can be used for realistic fuel cycle, dynamic safety, and other performance analyses of a SABR.