High strength ODS materials and joining technology development

With a recent accelerated evolution of nuclear reactors combined with ever-increasing world energy demands, Generation IV future nuclear systems has spurred considerable research and developmental interests in the world's major nations with nuclear power reactors because the Gen IV is believed to further improve efficiency, safety, reliability, and proliferation-resistance of nuclear reactors. Among the Gen IV future nuclear systems, the Republic of Korea is focusing on the development of a sodium cooled fast reactor (SFR) and a very high temperature reactor (VHTR). While there is continued effort and concern for the implementation of the fast reactors in the commercial nuclear reactors, unfortunately, it has not yet been substantialized, as well as studies and reports have shown that there are numerous challenges to overcome. A fundamental one of those challenges is difficulty in achieving efficiency and safety of the future nuclear reactors using the existing core structural materials. Accordingly, most of leading nations in the development of future nuclear systems realizes the importance of advanced materials as critical path to implement fully efficient and safe future nuclear systems, thus have intensively developed advanced materials for future nuclear systems as government lead research and development. Since the development of advanced nuclear materials is well known as the typical area of high-risk, high-reward R&D and is also required to evaluate in-pile test as well as post-irradiation examination for a long period, for the purpose of enjoying the technical dominant position in the field of future reactor systems and high temperature materials, the development of the advanced nuclear material such as oxide dispersion strengthened (ODS) steel which is applicable to future nuclear systems as the core structural component is urgently inevitable. ODS steel is a new alloy material manufactured through oxide dispersion using a mechanical alloying (MA) method to enhance the high temperature properties and radiation-resistance, in which the oxide is very small at nano-sized scale and is stable at an elevated temperature. Up to now, ODS alloys have been intensively studied and developed for possible application as nuclear cladding and structural materials due to the high strength and excellent creep properties, which are critical to nuclear material consideration for future nuclear systems. Therefore, the primary objective of this project is to establish high strength advanced material technology and joining technology through the development of high strength advanced ODS alloy, fabrication technology of structural components and basic joining technology.