China’s spent fuel production is increasing year by year, having already exceeded 1000 tons per year. At the same time, the inventory of spent fuel in storage in China is also growing, with approximately 90% of the cumulative production stored in nuclear power plant spent fuel pools at the end of 2020. With the in-pile storage capacity approaching saturation, the increased off-site storage capacity, and the completion of geological disposal facilities, there will be a large demand for spent fuel transportation containers. The radiation safety issues of spent fuel transportation containers have become an important research topic. The national standard “Regulations for the Safe Transportation of Radioactive Materials” (GB 11806) specifies the relevant requirements for the radiation shielding performance that transport containers for radioactive materials must meet. This work focuses on the AFA-3G type spent fuel assembly used in the HPR1000 reactor, and analyzes the relationship between neutron and photon emission intensity and burn-up for irradiated low-enriched uranium dioxide (UO2) fuel. The study calculates the neutron and photon emission intensities, as well as decay heat, for spent fuels with different initial enrichments, burn-ups, and cooling times. The analysis shows that there is a power-law relationship between neutron emission intensity and burn-up, with a larger power index for lower enrichments; and a shorter cooling time also results in a larger power index. There is a linear relationship between photon emission intensity and decay heat and burn-up. This research will provide reference for the shielding design and thermal transfer design of AFA-3G type spent fuel transport containers.