Structural materials in nuclear reactors. Activities of R and D in CIEMAT

Nuclear power plants life management, as well as their extended operation, is strongly related to the materials behaviour. Stress corrosion cracking of austenitic alloys, stainless steels and nickel base alloys, is one of the more penalising phenomena to the safe and reliable plant operation. Recently, the multiple circumferential cracks found in dissimilar welds in the pressurizer of Wolf Creek led to the revision of the inspections plan to guarantee the safety margin of the structural integrity evaluation. CIEMAT Materials division carries out research projects to study structural materials in representative conditions of light water nuclear reactors. These projects are performed in collaboration with international and spanish organizations, being the Spanish nuclear power plants some of them. the objective of this article is describe in a short way some of the running or recently finished experimental projects related to stress corrosion cracking performed in our laboratory. (Author) 15 refs