Monitoring of radiation effects to insure reactor vessel integrity

The owners of light water cooled nuclear power plants are required by Federal Regulations to monitor the radiation-induced changes in the mechanical properties of the materials employed in the construction of the reactor vessel. Test data obtained from the surveillance program allow determination of the margin of safety against fracture and a determination of the conditions under which the reactor vessel may be operated. Fracture mechanics techniques are employed to quantitatively define the margin of safety against fracture. An overview of the reactor vessel surveillance program and the methods employed to insure vessel integrity are presented