235 U enrichment detection system for nuclear fuel rod based on compact D-D neutron generator

A reliable 235 U enrichment uniformity detection system based on a compact D-D neutron generator is developed to detect the 235 U enrichment uniformity of different fuel elements in the same nuclear fuel rod. The high-yield compact D-D neutron generator provides 2.45 MeV D-D neutrons, decelerated by a moderator to thermal neutrons or epithermal neutrons, thereby inducing 235 U fission to produce highly excited state fission fragments that undergo de-excitation via γ-ray emission. The system detects the 235 U enrichment uniformity of a nuclear fuel rod by measuring γ-rays and establishing a relationship between the γ-ray count rate and 235 U enrichment in nuclear fuel. The proposed system yields a confidence probability of 99.99% for a relative 235 U enrichment deviation of 10% and a neutron yield of 5 × 10 8 n/s, and the detection accuracy increases with increasing neutron yield. Furthermore, the developed system can satisfy quality control requirements for nuclear fuel production to promote the safe development of nuclear power.