The neutronic feasibility of testing fusing firstwall/blanket systems in a fission reactor is investigated. Heating rates resulting from a 14-MeV fusion source are calculated with one-dimensional transport theory for two tokamak blanket designs and compared with heating rates computed for the same blankets in the Engineering Test Reactor (ETR). The designs studied are a gas-cooled, liquid-lithium blanket with no neutron multiplier and a water-cooled, solid lithium-aluminate blanket with a beryllium multiplier. Based on these preliminary results, it is concluded that bulk heating rate profiles expected in tokamak reactor blankets can be simulated quite well in large (65- × 76- × 91-cm) blanket experiment modules placed on one side of the ETR core. Heating rates corresponding to tokamak wall loadings of 1 MW/m2 can be achieved, and the level varied to simulate the cyclic operation typical of tokamaks.