The various commercial large power producing reactors are identified and described against a brief background of nuclear reactor principles and key reactor components Neutron Classification. TRIGA reactors use a U-ZrH or U-ZrH alloy fuel in Al or stainless steel cladding. Dr. John H. Bickel. Supercritical. Define multiplication factors of reactor systems: Subcritical. The various commercial large power producing reactors are identified Beyond existing large-scale nuclear reactors, nuclear power