Feasibility of fast reactor concept without any control rods: RAPID-A

A fast reactor concept without any control rods have been demonstrated to achieve inherent safety and fully automated reactor operation, and to provide reactivity control systems with maintenance free and reliable performance over the plant design lifetime. The design involves Lithium Expansion Module (LEM) for inherent reactivity feedback, Lithium Injection Module (LIM) for inherent ultimate shutdown, and Lithium Release Module (LRM) for automated reactor startup. Burnup compensation by LEMs enables 90% of full power operation even in the end-of-life core. LEMs also realize partial load operation minimum to 25% of full power by primary flow rate control. Deviation of core outlet temperature is less than 17 degrees celsius in both cases. In addition, LIMs assure sufficient negative reactivity feedback in ULOF and ULOHS transients. UTOP transient can be eliminated because no control rods equipped. (author)