BfS informs supervisory authorities about measured activity of a replaced filter

In September 2015, the Asse-GmbH detected during routine measurements that a filter for cleaning the exhaust air at the emplacement chamber for intermediate-level radioactive waste needed replacing. Over the years, radionuclides retained from the exhaust air concentrate inside the filter, so that the filter needs to be replaced in certain intervals. As the filter system has fully fulfilled its function, man and environment were not at risk at any time. Neither did the measurements of the exhaust air behind the filter show enhanced values.

Once the Repository Surveillance unit had given their approval, the filter was replaced. Before it was removed from the premises, the radioactivity level auf the dismounted filter was measured on the premises with a special device. On this basis the radioactivity concentration was estimated.

As the radioactivity concentration of caesium-137 measured in this filter has exceeded a certain value, this fact has to be reported to the Lower Saxon Ministry for the Environment, Energy and Climate Protection. For such a case, the licence provides for a report to the supervisory and licensing authority. The Asse-GmbH has informed the BfS as the operator of the Asse mine; the BfS has then reported the facts to the competent authorities.