In order to reduce the volume and the radiotoxicity of the nuclear waste coming from the operation of existing pressurized water reactors, accelerator-driven systems (ADSs) have been envisioned. The Lead-Cooled (Pb) European Facility for Industrial-Scale Transmutation (EFIT) (Pb-EFIT) plant is the first ADS design that has been going into a rather detailed engineering level. It is a lead-cooled, 385-MW(thermal)ADS prototype for minor actinide (MA) transmutation designed to achieve an optimal MA destruction rate of ;42 kg/TW{h(thermal). The spallation target unit is located in the center of the diagrid where 800-MeV protons from the accelerator impinge on a free surface of lead exposed to vacuum. The core inlet temperature was set at 4008C to assure a sufficiently large safety margin to lead freezing, and the core outlet temperature was limited to 4808C to allow acceptable corrosion. The ferritic-martensitic 9% Cr steel T91 protected against corrosion with alumina FeCrAlY [GESA (Gepulste Elektronen Strahl Anlage) treatment]. The primary circuit is designed for effective natural circulation, i.e., relatively low pressure losses, and the design offers good protection for a heat removal system in case of a blackout accident. The EFIT plant is designed to have a low likelihood and a low degree of core damage, to eliminate the need for off-site emergency responses in case of a severe accident, to use an extensively reliable passive safety system to fulfill the safety functions, and to eliminate the need of alternating-current safety-grade power (no safety-grade diesel generator). Three systems contribute to the decay heat removal (DHR) function of Pb-EFIT: the steam generators, the direct reactor cooling system, and the isolation condenser system. The EFIT plant exhibits four primary pumps; eight steam generator units, each rated at 52MW, provide heat removal under normal operation. On the secondary side, the water steam ensures a thermal efficiency of ;40% with the superheated vapor secondary circuit, taking into account the electricity required by pumps ( from both the primary circuit and the secondary circuits) but without deducing the power required for the accelerator. An estimate of the Pb-EFIT plant cost has been performed based mainly on experience and engineering judgment. A best estimate (base cost and contingency) of about Y1890 million, with an overall uncertainty of 22%, has been found.