Demolition and dismantling of the Karlsruhe Reprocessing Plant (WAK)

When the intention to build an industrial reprocessing plant was given up, operation of the Karlsruhe Reprocessing Plant (WAK) was discontinued for good in 1991. The high-level liquid waste stored on site is to be vitrified, the process installations containing a residual radioactivity inventory are to be dismantled, the building structures cleared for removal and demolished, and the site is to be re-cultivated. On the basis of the contamination status of WAK after the termination of reprocessing operations, a radiation protection concept was developed for demolition and dismantling in close cooperation with the supervisory authority. Demolition and dismantling of each plant section follow a standardized procedure: (1) Providing access to the site of demolition and dismantling for persons and material by means of ventilation and technical processing systems. (2) Dismantling and crushing of components. (3) Packaging, declaration, and disposal of residual materials. (4) Decontamination and dismantling of the new installations. (5) Clearance measurement of the empty spaces. In the techniques employed in demolition and dismantling, a distinction must be made between the tools and the support systems required to operate them. For cutting purposes, electric compass saws, abrasive cutters, and hydraulic shears so far have been used with convincing success. Unless work is performed manually, the equipment supports used are cranes, manipulators, and hydraulic excavators getting the tools into their proper working positions. Depending upon the radiation fields existing, work is performed under direct viewing conditions, partly behind shielding windows, or remotely by means of video cameras. The article covers the current status of the demolition project as well as experience accumulated in manual dismantling, semi-remotely controlled dismantling and demolition under direct viewing conditions, and dismantling controlled remotely by video cameras, and also refers to the radiation protection and the waste management concepts. (orig.)