Materials research for future Generation IV fission plants

The increasing demand on electric energy and heat produced in a sustainable manner led to a revival of research for nuclear plants. International research projects are launched within the Generation IV initiative. Six different reactor concepts were proposed of which currently the sodium fast reactor (SFR) and the gas cooled very high temperature reactor (VHTR) are internationally considered as most important concepts. The long service times envisaged (60 years), a save and reliable operation together with demanding service conditions well above those for currently used light water reactors make materials and life-time assessments to important research themes. Creep damage (thermal induced and irradiation induced), fatigue, irradiation and thermal ageing are very important research topics. Design codes must be adapted and new techniques for damage assessments combining modeling and experimental model validation (multiscale approach) become important. The paper summarizes current developments taking mainly gas cooled reactors as an example. (orig.)