(502b) Characterization of Structural Materials for Nuclear Hydrogen Generation

Generation of hydrogen as an alternate source of energy using nuclear power is creating significant global attention. While different routes are being explored to achieve this goal, the use of thermochemical processes such as a sulfur-iodine (S-I) cycle is a leading technique, which is currently being preferred by the United States Department of Energy. The S-I cycle involves the decomposition of hydroiodic acid at elevated temperatures leading to the formation of hydrogen. A several structural materials have been identified to characterize their metallurgical and corrosion behavior in environments relevant to the nuclear hydrogen generation system. This paper presents the results of stress corrosion cracking, hydrogen embrittlement and localized corrosion studies of a few refractory materials such as Zr702, Zr705, Nb7.5Ta and Nb1Zr. In addition, the results of tensile testing of these materials at ambient and elevated (up to 400oC) temperatures will be included. The metallographic and fractographic data will also be presented in this paper.