Towards Next Generation Accelerator Driven Subcritical System

Abstract: Accelerator Driven sub-critical System (ADS) is considered to be the most important candidate for nuclear waste transmutation. We propose a Multi-Target Accelerator Driven System (MTADS) to resolve two longstanding challenges of ADS, namely heat removal and the associated target lifetime, and inhomogeneous power distribution that affects burn-up of the reactor. An 18 mA, 1 GeV proton beam is split into 12 beams by radio frequency cavities and injected to 12 compact targets inside the reactor. With beam power of 18 MW, the sub-critical reactor is driven to 1500 MW thermal power. The peaking factor of the reactor is reduced to 1.7 by optimization of targets number and position for Multi Target Accelerator Driven System. The maximum beam current density is also reduced to 18.5 μA/cm2, which prolongs the beam window lifetime to 12 months with T91 steel. Towards the next generation ADS, the concept of MTADS simplifies the sub-critical system and increases the transmutation efficiency.