An in-depth nuclear analysis has been performed for WILDCAT that is a conceptual design of a commercial tokamak reactor utilizing a catalyzed deuterium-deuterium (D-D) fusion fuel cycle. Comparisons are made with the deuterium-tritium-fueled STARFIRE design in order to identify the salient features of D-D tokamak reactor designs. Since WILDCAT does not have to breed tritium, the blanket and shield system can be optimized to have a thinner inboard extent (∼0.8 versus 1.2 m for STARFIRE) leading to more efficient use of the toroidal field. The nonbreeding blanket concept of WILDCAT can also be utilized for substantial enhancement of the system energy multiplication (2.02 versus 1.14). These benefits help to overcome the reduced fusion reactivities and lead to a 60% more efficient blanket in terms of power generation. The outboard blanket and shield'system has been designed for personnel access within 24 h after reactor shutdown and uses as much as possible materials that are not resource limited and that have lower activation. Ninety percent of the materials in WILDCAT can be recycled within 50 yr after their discharge from the reactor.