Project group clears leaching test field
The Institute for Knowledge Analysis and Knowledge Synthesis (IWW) of Helmholtz Zentrum München is clearing the so-called leaching test field on the 490-m level of the Asse II mine. On request of the supervisory authorities, the former operator carried out long-term tests with test specimens in this area from 1979, after the emplacement of radioactive waste had stopped. In these tests it was examined how radioactive materials contained in concrete samples are released when they come into contact with different salt solutions.
On 12 March 2013, twelve test specimens consisting of concrete including the leaching liquids having generated in the tests were taken from the Asse II mine in altogether 13 containers.
In the 41st calendar week 2013, 58 drums containing operational radioactive waste have now been transported in a first lot to the Lower Saxon federal state collecting depot. At least one further transport of operational radioactive waste to the Lower Saxon federal state collecting depot is required.
In the summer of 2012, Helmholtz Zentrum München filed an application to the Lower Saxon Ministry for the Environment, Energy and Climate Protection (NMU) for the clearance of the leaching test field, which was approved on 9 November 2012.
Activity of test specimens is clearly lower than the activity of the radioactive waste emplaced
Both the test specimens and the leaching liquids contain small amounts of radioactive materials. For the tests, the former operator had added small amounts of radioactivity as markers to the test specimens. This was done to observe the behaviour of radioactive materials in salt solutions without damaging real waste at the same time or releasing radioactivity unintentionally.
The activity of the test specimens is about one hundred thousandth of the radioactive waste stored in the Asse mine. The test specimens can thus not put on a level with the radioactive waste stored in the Asse mine.
Test evaluation at the Karlsruhe Institute of Technology
The IWW took the specimens to the Karlsruhe Institute of Technology for the evaluation of the test. The transport was carried out in special transport containers that have been approved for the shipment of low-level radioactive materials (so-called IP-2 packages used for low-level radioactive material in the industry).
Removal of operational radioactive waste
While the long-term tests are carried out in the leaching test field, solid and liquid radioactive wastes have been produced. In accordance with the prescribed waste management path, these wastes have now been transported to the competent Lower Saxon federal state collecting depot. Like before with the test specimens, the transport was carried out with IP-2 containers approved for the transport of this type of radioactive material.
Under nuclear law, Helmholtz Zentrum München is responsible for the leaching test field
The former operator carried out long-term tests in the leaching test field, starting in 1979. In these tests it should be examined how radioactive materials contained in concrete samples are released when they come into contact with different salt solutions. Also after the operator responsibility for the Asse II mine had been taken over by the Federal Office for Radiation Protection (BfS), the leaching test field remained the responsibility of Helmholtz Zentrum München under nuclear law. Helmholtz Zentrum München is thus also the owner of the radioactive materials and specimens stored there and of the conventional waste.
Handing over of the leaching test field to the BfS only after successful clearance procedure
Only after a successful clearance procedure under nuclear law will the leaching test field be handed over to the BfS. The removed test specimens and leaching liquids and the operational radioactive wastes are not part of the planned retrieval.