Melting of radioactive metal scrap from nuclear installations

Within the time of 1984 to 1989 in Germany the process of melting radioactive scrap was established. Up to now more than 2000 tons of low level contaminated scrap (≤ 74 Bq/g) have been melted and recycled. Looking to the scrap which was shipped to the plant, about 95 % of the activity was Co 60 and Cs 137. In the average the ratio between Co and Cs was 60 : 40. This is a ratio, which might be different in other plants, especially in plants which have no bigger damage on fuel elements, the Cs contents should be lower. Cs quantitatively was found in slag and filter dust, whereas cobalt remained in the melt. A separate and modernised facility had to be erected taking into consideration the results from the previous tests. The maximum activity level to be handled will be 500 Bq/g. It is planned to test here the ''onion-casting'' as it was described by the KRB-A plant people. A first casting was done using non-contaminated material. (author)