Gamma Scanning of Spent Fuel Element from PWR

4 intact and 4 failed spent fuel elements from PWR with burnup range of 9600-45 000 MW•d/t（U） were measured by gamma scanning, and the axial Cs distributions were obtained, which can indicate the burnup distribution of the intact elements and the Cs loss of the failed elements. The results show that there are different degrees of Cs migration and loss in the failed elements, and there is a Cs counting mutation (decrease) at the failure position. The distribution of ¹³⁴Cs/¹³⁷Cs atom ratio of one failed element is basically the same with the sibling intact element, indicating that the loss ratio of ¹³⁴Cs and ¹³⁷Cs is approximately equal, and the relative burnup distribution can be characterized by the atom ratio. The low volatility fission product ¹⁵⁴Eu can be used to identify the fuel pellet damage. The results can provide an important basis for the failure cause analysis and the in-pile behavior analysis.