High-Priority R&D Problems of Advanced Fast Sodium Reactors

Abstract

The transition to new design and circuitry requires careful validation of the efficacy of the new solutions. For the sodium-water BN-1200 macro-modular steam generator, the damage is determined by the failure of the structural material in the zone of a water leak into the sodium and the amount of water entering the coolant. The parameter that ultimately determines the magnitude of the damage is the time interval between the start of a small leak and the actuation of the steam generator’s protection system. Acoustic methods are effective for decreasing the lag of the indication system. The design is based on the use of two-frequency ranges – vibro-acoustic (0.1–40 kHz) and ultrasonic (40–500 kHz) – of high-sensitivity acoustic sensors, and fast software-hardware methods of analyzing acoustic signals in real-time. The presence of thermal insulation and protective jackets on the sodium equipment and pipelines strongly affects the character of the outflow and burning of the sodium and eliminates dispersal. Analysis shows that there are strong grounds for reducing the conservatism (safety margins) in studying emergency regimes associated with sodium leaks.