Conditioning of fuel element skeletons and other core components in the KBR

During the annual inspection of a nuclear power plant (NPP), spent activated parts are regularly disassembled from the reactor core (core components). The core components are initially placed into the storage basin for fuel elements. Because there are only a limited number of positions for spent fuel elements in the storage basin, the core components require disposal. In order to place the core components in an intermediate or final repository, they need to be conditioned. On account of their high specific activity, the acceptance conditions in the intermediate storage locations or a future final repository require their conditioning in thick-walled shielding casks (e.g. model KONRAD II). For reasons of radiation protection, the conditioning of core components is only possible using special techniques, e.g. underwater dismantling facilities and equipment for underwater packaging of the dismantled core components into the shielding casks. In 2001, at the NPP Brokdorf, 25 fuel element skeletons, 2 flux distribution detector lances, the structural components of 2 primary neutron sources, 2 reactor pressure vessel (RPV) level measuring sensors, a pump as well as a large number of activated small parts were to be conditioned. The larger components were dismantled under water with underwater shears of type UWS III and then placed in an underwater box (UWB). Subsequently, the cut sections and small parts were transferred under water into MOSAIK registered inserts which were then placed in MOSAIK registered II-15 P/U casks. The lids of the MOSAIK registered casks were put on under water, then the casks were lifted out of the fuel element storage basin, drained by means of a tilting device and vacuum-dried. During the conditioning procedure at NPP Brokdorf, core components with a mass of approx. 1.9 Mg were transferred to 13 MOSAIK registered II-15-P/U casks. Some of the resulting waste packages have already been sent to the Gorleben waste repository. (orig.)