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Dismantling of primary shielding with prototype machines in a compact sodium cooled reactor - 15463

Conference ·
OSTI ID:22824362
;  [1];  [2]
  1. WAK Rueckbau- und Entsorgungs-GmbH, P.O.Box 12 63, 76339 Eggenstein-Leopoldshafen (Germany)
  2. Siempelkamp Nukleartechnik GmbH, Am Taubenfeld 25/1, 69123 Heidelberg (Germany)
The Compact Sodium Cooled Reactor Facility Karlsruhe (KNK), a prototype reactor to demonstrate the Fast Breeder Reactor Technology in Germany, was in operation from 1971 to 1991. The dismantling activities started in 1991. The project aim is the green field in 2020. Most of the reactor internals as well as the primary and secondary cooling loops have already been dismantled. The contaminated sodium inventory has already been disposed of completely. Only the highly activated reactor vessel shielding structures remain. Due to their high dose rates, these structures must be dismantled remotely. For the removal of the primary shielding of the reactor vessel, 12 stacked cast iron blocks with a total mass of 90 Mg and individual masses of up to 15.5 Mg, a remote-controlled multifunctional dismantling device (HWZ) was designed, manufactured and tested in a mock-up. Since it is not possible to remove the segments in one piece for offsite treatment, a special prototype band-saw (BWZ) had to be developed for sawing the segments both horizontally and vertically into smaller pieces. The resulting sub-segments are transferred directly into repository containers. After the successful approval of the test sequences by the authorities and intensive training of the operational staff, both prototype machines were installed inside the reactor building containment for final assembly. The dismantling started in 2013. The present paper covers the successful dismantling of the primary shielding as well as the experiences gained through the development, use and improvement of these prototype machines. (authors)
Research Organization:
WM Symposia, Inc., PO Box 27646, 85285-7646 Tempe, AZ (United States)
OSTI ID:
22824362
Report Number(s):
INIS-US--19-WM-15463
Country of Publication:
United States
Language:
English