Research on the Control System of Thorium-Based Long-Life Core

In the thorium-based long-life reactor, the thorium-spent fuel plutonium mixed fuel and lead-bismuth coolant are used to design a fast neutron spectrum core. This paper studies the control system in the long-life core and gets some useful conclusion. The control system includes two parts: the central control rod and a peripheral control unit that surrounds the core. The paper studies the thickness of the absorber, which influences the neutron absorb capability and economy, and gives the relation between the thickness and the reactivity. A peripheral reflector is used in most small fast neutron spectrum critical equipment to control the reactivity. The paper discusses the absorber mode and the reflector mode in peripheral control unit design. The paper gives the final design details of the control system in the thorium-based long-life core reactor. The control system has high control efficiency and achieves the requirement of the long-life core.