2015

Novotny, Radek; Janík, Premysl; Toivonen, Aki; Ruiz, Anna; Szaraz, Zoltan; Siegl, Jan; Hausild, Petr; Penttilä, Sami

The main target of the HPLWR Phase 2 follow-up FP7 project “Fuel Qualification Test for Super Critical Water Reactor” is to make significant progress towards the design, analysis and licensing of a fuel assembly cooled with supercritical water in a research reactor which also includes the material research on those in-core materials which could be licensed in near future. In frame of WP4 - Pre-qualification, stress corrosion cracking (SCC) resistance of three selected austenitic stainless steels 08Cr18Ni10Ti (equivalent of AISI 321), AISI 347H and AISI 316L was investigated by conducting slow strain rate tensile tests in an autoclave in 550°C supercritical water. SCC susceptibility was evaluated using three criteria: loss of mechanical properties compared to those in inert environment, fractographic analysis of the fracture surfaces and finally analysis of secondary cracks. Obtained results were compared to those available in the literature and utilization of these results is discussed. Based on the results of SSRT tests and following fractographic analysis, 316L was selected as the best performer.