Speaker
Description
Waste conditioning, handling and storage is a challenging task not only during operation and decommissioning of nuclear sites, but also in other areas like science and research.
Usually waste is packed in drums where a detailed documentation of the drum content is mandatory.
In many cases e.g. due to the change of regulatory requirements it becomes necessary to re-characterise waste drums as the existing documentation does not give sufficient details about the nuclear inventory of the waste packages. In these cases one simple way is to measure the dose rate on the surface but due to inner shielding effects, the true activity content cannot be obtained. The more accurate way is to characterise the waste by using High Purity Germanium Detectors which can determine the activity for each nuclide inside the waste drum.
But nuclide specific waste characterisation requires detailed information of the waste content and activity distribution in order to achieve as accurate results as possible.
If the waste content or activity distribution is not available, assumptions are made which represents the worst case scenario. This often leads to definitions of additional, so called virtual activities.
Mirion Technology (Canberra) has developed in cooperation with the Aachen Institute for Nuclear Training (AiNT) a novel approach which allows determining the spatial activity distribution inside the waste drums by scanning the drum in single sectors. The so called Advanced Sectorial Gamma Scanner (ASGS) uses the Efficiency Calibration for Inhomogeneous Activity Distribution (ECIAD) to analyse the spectra of each sector.
A validation campaign which was performed with a test system showed a significant improvement of accuracy versus standard waste characterisation systems which leads to a reduction of conservative assumptions and therefore to reduction of waste handling and storage costs.
| Speaker's title | Mr |
|---|---|
| Affiliation | Mirion Technologies (Canberra) |
