The U.S. Department of Energy requires nuclear criticality control measures for storage of its highly enriched spent nuclear fuel. A new alloy based on the Ni-Cr-Mo alloy system with a gadolinium addition has been developed. Gadolinium has been chosen as the neutron absorption alloying element because of its high thermal neutron absorption cross section. The metallurgical development, mechanical and physical properties, thermal neutron absorption properties, and accelerated corrosion-testing performance of this Ni-Cr-Mo-Gd alloy is described. A brief comparison is also included of the corrosion performance of this alloy as compared to borated stainless steel, which is commonly used as a neutron-absorbing, structural alloy.