Optimization study on neutronics and self-regulation of cold neutron source for China Advanced Research Reactor

The feasibility of the new cooling method in the world, two-phase thermo-siphon with auxiliary cooling, was studied in order to resolving the difficulties in the desigh of China Advanced Research Reactor （CARR）cold neutron source （CNS）. On the basis of feasibility of new cooling method, the shape of liquid hydrogen in moderator cell was optimized and the better configuration of moderator cell is founded by lots of neutronics analysis. Additionally, the self-regulation characteristics, which is most important to the stable operation, was researched and the equation of one-order inertial self-regulation was derived by the study of non-balanced thermodynamics analysis. Analysis to the equation results shows that good self-regulation characteristics could be possessed of and optimized.