The FED/INTOR Critical Issues activity examined three key testing requirements that have the largest impact on the design, operation and cost of FED/INTOR. These are: 1) the total testing time (fluence) during the device lifetime, 2) the minimum number of back-to-back cycles, and 3) the neutron wall load. These requirements were quantified by investigating the benefits/risks to the DEMO from testing structural materials, blankets, and main reactor components in FED/INTOR.