Interest in generating energy with thorium fuel has increased lately as a result of the activation of subcritical ThO2 lattices by accelerated protons. A tight, ThO2 water-cooled lattice has been proposed to generate 200 MW(thermal) with 1.5-GeV protons in a current of ∼7mA. A tight-latticed core, consisting of a ThO2/233UO2 seed embedded in a large ThO2 blanket, has been proposed to generate 2400 MW(thermal) with 1.0-GeV protons in a current of 20 mA. A consistent detailed analysis of these two energy amplifiers, carried out with the HERMES, MCNP, KORIGEN, WIMS, and BOXER codes, results in performances inferior to those claimed. The net power generated will be one-fourth of that claimed for the former and 1/2.5 of that claimed for the latter.