Correlation of the Cesium-134/Cesium-137 Ratio to Fast Reactor Burnup

The correlation of ¹³⁴Cs/¹³⁷Cs to burnup in irradiated fast reactor fuel pins was investigated using nondestructive precision gamma-ray scanning. This correlation was significant within individual subassemblies provided certain basic assumptions are satisfied. The calibration line must be calculated for each assembly based on independently measured burnup values. Differences in calibration lines for separate subassemblies are highly significant (P < 0.005). Therefore, application of this technique for the nondestructive measurement of burnup in fast reactor fuels has serious problems that must be considered.