Reconditioning of Historic Radioactive Waste in Austria - Experiences with and Status of the Project

At Nuclear Engineering Seibersdorf GmbH (NES) all radioactive substances produced in Austria are, on behalf of the Republic of Austria, collected, safely conditioned and temporarily stored until their final disposal.This agreement has been expanded until 2045, leading to investments in new buildings and technical equipment to assure the stability of the waste until final disposal. The main projects to achieve this goal are: The construction of a New Handling Center (NHZ) for radioactive waste, the construction of new interim storage halls ("Transfer Storage") and the reconditioning of old, historic waste drums.The project has been implemented in three phases which correspond to the three main types of drums to recondition:The first phase concerned 200- Liter drums with supercompacted pellets. The pellets therein have been repackaged, dried and analyzed by gamma-scanning. About 1500 drums were treated that way. This phase has been completed.The second phase concerns homogenously cemented sludges, salts and ashes. These drums are being dismantled using custom made machinery and then milled (for sampling and reduction of the radius) before they are being repackaged and analyzed via gamma-scanning. The milling samples are also being analyzed chemical and radiochemical. This phase of the project is ongoing. Over 1000 drums have been reconditioned in this way.The third phase concerns 100-Liter drums with raw radioactive waste that has been formerly cemented into 200-Liter drums. We call these drums in-homogenously cemented. These drums are also being dismantled using the same machinery as in phase 2. Then the concrete lining is being removed before the 100-Liter drum is inspected. Depending on the contents of the inner drum, these are being repackaged into cartridges for supercompaction or – in case of burnable waste – repackaged into plastic bags for incineration. Sampling is also done on one drum per week. This phase of the project is ongoing. Over 400 drums have so far been reconditioned this way.In all phases – especially in phase 2 and 3 – considerations for waste minimization are being upheld. Especially phase 2 drums are being considered for free release and phase 3 drums are being reduced in volume. (author)