Preliminary studies of compact Brayton cycle performance for Small Modular High Temperature Gas-cooled Reactor system

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>A High Temperature Gas-cooled Reactor (HTGR) system was generally designed and planned to be constructed in a medium size reactor (around 600MWe power output) in the past. In this paper, authors are exploring the potential of very small modular type HTGR with a special attention given to the power conversion system. Since HTGR is relatively less challenging to achieve passive safety while easy to adopt an air-cooled Brayton cycle for a power conversion system, HTGR can be suitable for a small modular reactor application. However, as the size of the power system decreases the consisting component performance usually degrades and the final effect on the total system performance was not seriously studied before for a small size HTGR system. 20MWth reactor was chosen for this study to investigate how helium Brayton cycle performance can be affected by the component level performance and how the optimal operating condition shifts when the system size reduces. The discussion of component design that can deliver assumed performance for the cycle estimation will be briefly presented as well. Furthermore, a supercritical CO<SUB>2</SUB> cycle option will be compared to the helium Brayton cycle to show that the S-CO<SUB>2</SUB> cycle can be a good alternative for a very small scale system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We are exploring the power conversion system for the very small modular type HTGR. </LI> <LI> Helium Brayton cycle for 20MWth SM-HTGR was studied to evaluate the cycle features. </LI> <LI> The comparison between S-CO<SUB>2</SUB> Brayton cycle and helium Brayton cycle was performed. </LI> <LI> Cycle analysis was conducted while considering various turbomachinery efficiencies. </LI> </UL> </P>