Conceptual design of a fast breeder reactor cooled by supercritical steam

Abstract The steam-cooled fast breeder reactor with negative reactivity characteristics against voiding and flooding is feasible under the supercritical pressure. The breeding ratio is 1.04. A flat core with a zirconium hydride layer is adopted for mitigating the void reactivity. The thermal efficiency of the indirect cycle system is improved 9% relatively from current PWRs. The core should be cooled in 10 s after the large break LOCA. The coast down time should be larger than 30 s to overcome the LOF by the trip of all blowers.