The ANTECH G3250-220 Wide Range Segmented Gamma Scanner (WR-SGS) builds on the segmented gamma scanning technique to measure the radionuclide content of waste drums. The technique is applicable to the measurement of activity from extremely low levels to extremely high levels and across a large range of densities. It is capable of measuring waste in a variety of matrices and chemical forms and is particularly applicable when the chemical form and the relationship between the nuclide and matrix are unknown.
As in the standard Segmented Gamma Scanner (SGS), the drum or sample is rotated about its vertical axis as horizontal segments are scanned. This allows for any inconsistencies in the matrix density whilst building a vertical profile of gamma-ray transmission and nuclide concentration.
The ANTECH G3250-220 is the first system to utilise both the storage of the transmission source within a tungsten shielded safe and a fully automated variable collimator aperture. The variable aperture collimator greatly increases the range of activity that can be assayed on one measurement system without the need for any manual alteration. Laser alignment during assembly and PLC motor control ensures optimum alignment of the transmission source and the detector once the source leaves the safe. When the transmission source is stored in the safe, there is typically a leakage of less than 5 μSv/hr near the surface of the safe. In the safe storage position the detector does not detect any gamma-rays from the transmission source.
The ANTECH implementation of the wide range segmented gamma scanning technique in the Model G3250-220 complies with the Standard Test Method for Non-destructive Assay by Segmented Passive Gamma-ray Scanning, ASTM number C1133-03.