Development of a segmented gamma ray scanning system

A segmented gamma ray scanning system was developed for the purposes of non-destructive assay of the contents of uranium, plutonium or fission products existing in packed low density or median density unclear residuals, scrapes or wastes. Near-field three-dimensional model for computing CF(AT) was used for cylindrical sample and container. Full scale scanning of samples, spectrum accumulation and data reduction can be fulfilled automatically according to preset standard procedures. Radioisotopes of 169Yb and 75Se were used as transmission sources for assaying 235U and potential 239Pu respectively. Calibration of this system was performed using 192Ir and 235U. Standard deviations obtained for 192Ir gamma ray of 295 keV, 308 keV and 316 keV are ��0.41%, ��0.29% and ��0.42% respectively. The standard deviation for 235U 185keV gamma ray is ��0.62%.