Neutronics Design of a Small LBE Cooled Accelerator Driven System CIADS

As an important part of advanced fuel cycle R&D, conceptual study of accelerator driven system (ADS) in China started since 1995. In 2000, China Institute of Atomic Energy (CIAE), Institute of High Energy Physics (IHEP) and other institutes started a ten-year project aiming at ADS fundamental R&D on physics and related technologies, which is one item of “Key Project of Chinese National Program for Fundamental Research and Development (973 Program)” in energy domain. In order to get a better understanding of ADS neutronics characteristic, China Fast Reactor Research Center initiates a preliminary R&D program focused on neutronics design of a small lead-bismuth eutectic cooled ADS with fast spectrum. In this program, the reactor core of a 10MW thermal power ADS called CIADS (China Initiative ADS) with MOX fuel has been studied and designed. For generally concerning, CIADS can operate in either subcritical or critical mode. Different parameters, such as target size and position, position that transmutation assemblies are placed have been studied during the design work. Results show that a half size target and one zone loading can meet the needs for a small size ADS. Moreover, some important physical parameters of CIADS, such as k_eff, k_s, power peak factor and neutron maximum flux density are evaluated. According to the R&D work, it’s appropriate to set the k_s of CIADS at 0.96∼0.98.