ASME STP/NU-038

Description / Abstract: This report will first review the different concepts of IHX that could be envisioned for HTR/VHTR applications in a range of temperature from 850 to 950°C. This will cover shell-and-tube and compact designs (including the plate-fin concept). The review will then discuss the maturity of the concepts in terms of design, fabricability and component testing (or feedback from experience when applicable). Particular attention will be paid to the feasibility of developing the IHX concepts for the NGNP with operation expected in 2018-2021. This report will also discuss material candidates for IHX applications and will discuss specific issues that will have to be addressed in the context of the HTR design (thermal aging, corrosion, creep, creep-fatigue, etc). Particular attention will be paid to specific issues associated with operation at the upper end of the creep regime.