This study presents the material challenges associated with Advanced Reactor Concepts (ARC) such as the Advanced High Temperature Reactor (AHTR). ARCs are the next generation concepts focusing on power production and providing thermal energy for industrial applications. The efficient transfer of energy for industrial applications depends on the ability to incorporate cost-effective heat exchangers between the nuclear heat transport system and industrial process heat transport system.
The heat exchanger required for AHTR is subjected to a unique set of conditions that introduce several design challenges not encountered in standard heat exchangers. The corrosive molten salts, especially at higher temperatures, require materials throughout the system to avoid corrosion, and adverse high-temperature effects, such as creep. Given the very high steam generator pressure of the supercritical steam cycle, it is anticipated that water tube and molten salt shell steam generators heat exchanger will be used.
In this paper, the American Society of Mechanical Engineers (ASME) Section III and Section VIII requirements (acceptance criteria) are discussed. Also, the ASME material acceptance criteria (ASME Section II, Part D) for high temperature environments are presented. Finally, lack of ASME acceptance criteria for thermal design and analysis are discussed with potential benefit.