Progress in alloy development in the fusion materials program

This paper describes the various alloy paths of the Alloy Development for Irradiation Performance (ADIP) program for the U.S. Magnetic Fusion Energy (MFE) effort. In particular, the progress in and underlying reasons for alloy development of the Path A (Austenitic Stainless Steel) alloys are highlighted, because we have considerable data on these in a variety of reactor irradiation environments. These results at least indicate that microstructural management of helium will be important in resisting property degradation in the first wall, such as swelling and embrittlement. Because alloy development is less advanced for the other alloy paths, some general principles for alloy development are extended from Path A to the other paths. (orig.)