Structure Design and Experimental Verification of Safety Rod System on Uranium-rod Grid Critical Assembly

In order to meet the requirements of nuclear safety regulations and emergency shutdown of uranium-rod grid critical assembly, a safety rod system composed of eight cadmium rods side by side was designed, and the electromagnet was powered off to realize rapid falling, so as to achieve the purpose of emergency shutdown. The experimental results show that the system has stable and reliable performance and good repeatability. The safety rod value is 1.125×10^-2 Δk/k and fast falling time is (0.363±0.002) s, which meets the requirements of nuclear safety regulations. This provides a guarantee for the safe operation of uranium-rod grid critical assembly water reactor.