The integrated reactor vessel material surveillance program was initiated in 1977 as the direct result of two driving forces: (1) the need to obtain better characterization of fracture toughness data for irradiated weld metals to ensure continued licenseability of operating plants, and (2) the requirements for alternative irradiation schemes brought about by the failure of surveillance capsule holder tubes in six operating reactors. The program has two parts—the plant specific program and the research capsule program. The plant-specific program involves the continued irradiation of the surveillance capsules removed from those reactors in which the capsule holder tubes were damaged along with the capsules from the radiation site reactor vessels. The second part comprises special research capsules designed to provide fracture toughness data on a series of weld metals similar to those in the reactor vessel that are predicted to exhibit high sensitivity to irradiation.