Calculation of Calibration Factors and Layout Criteria for Gamma Scanning of Waste Drums from Nuclear Plants

This work presents (a) a procedure to calculate calibration factors for converting the measured gamma rate of waste drums into activity content and (b) a layout and free release measurement criterion for waste drums. A computer program is developed that simulates drum scanning techniques, which calculates calibration factors and eliminates laborious experimental measurements. The calculated calibration factors exhibit good agreement with experimentally determined values. By checking the calculated calibration factors for trial equipment layouts (including the waste drum and the scanning facility) using the layout and free release measurement criterion, a layout can be achieved that clearly determines whether there can be free release of a waste drum.