Haw-project. An underground demonstration facility for the disposal of high-level waste in salt.

In order to demonstrate the safe disposal of High-Level Radioactive Waste (HAW) in salt thirty highly radioactive canisters containing the radionuclides Caesium 137 and Strontium 90 in quantities sufficient to cover the bandwidth of heat generation and gamma radiation of genuine HAW will be emplaced in six boreholes located in two test galleries at the 800-m-level in the Asse salt mine in the Federal Republic of Germany. For the emplacement of the radioactive canisters a complete handling system consisting of an above ground transfer station, an underground transport vehicle, a disposal machine, and a borehole slider was developed. A scientific investigation programme on the interaction of the radioactive canisters and the rock salt is performed in situ as well as in the laboratory. This programme includes measurement of thermally and radiolytically induced water and gas release from the rock salt and the radiolytical decomposition of salt minerals. For gamma dose and dose rate measurements in the test field a measuring system consisting of ionisation chambers and solid state dosemeters was developed. Thermomechanical computer code validation is performed by calculational predictions and parallel investigation of the stress and deformation fields in the underground test field