Preliminary Analysis of Nuetronic-Source Transients in a Small ADS Prototype

A preliminary core-dynamics analysis of some typical current transients has been carried out for an 80 Mw Energy Amplifier Prototype fuelled by U/Pu mixed oxides and cooled by a molten Lead-Bismuth alloy. Temperature trends relevant to Recovered Beam-trip and Beamjump events have been preliminarily investigated. Beam-trip results show that the drop in temperature of the core-outlet coolant would be fairly reduced if the beam intensity could be recovered within few seconds. The worst thinkable current transient Beam-jump from zero power mainly depends on the coolant flow conditions. In the EAP design, the primary-loop coolant flow is assured by natural convection and it is enhanced by a particular system of cover gas injection into the bottom part of the riser. If this system of coolant flow enhancement is assumed working, even the Beam-jump from zero power event evolves without severe consequences.