Bituminization of the dowtherm

Dowtherm, an eutectic mixture of diphenyl C6H5-C6H5 and diphenyloxide C6H5-O-C6H5 in the ratio 26.5%: 73.5% has been used for the cooling and storage of the spent fuel elements at the NPP A-1 in Jaslovske Bohunice. The technological process and product properties of bitumen which is relevant to the immobilization of radioactive dowtherm from NPP A-1 are discussed. Results are give from the experiments devoted to both the verification to the inactive dowtherm bituminization in the laboratory and to establishment the basic parameters of the laboratory equipment. The results are given of verification of inactive and active dowtherm bituminization on the pilot-plant facility. The basic physico-chemical properties of the bitumen samples with the embedded dowtherm are discussed, too. The paper gives the proposals for the dowtherm bituminization technology and the results from the verification of inactive dowtherm bituminization