CHEMICAL DECONTAMINATION FOR DECOMMISSIONING PURPOSES
The aim of the research activities described was to develop vigorous decontamination techniques for decommissioning purposes, taking into account the cost of treatment of the radwaste, to achieve possibly unrestricted release of the treated components, and to obtain know-how for in-situ hard decontamination. The decontamination procedures for strong decontamination have been optimized in static and dynamic tests (DECO loop). The best values have been found for: (i) hydrochloric acid: 4 to 5 % vol. at low temperature, 0.7 to 1 % vol. at high temperature (80 degrees C); (ii) hydrofluoric plus nitric acid: 1.5 % vol. HF + 5 % vol. HNO-3 at low temperature; 0.3 to 0.5 % vol. HF 2.5 to 5 % vol. HNO-3 at high temperature. High flow rates are not necessary, but a good re-circulation of the solution is needed. The final contamination levels, after total oxide removal, are in accordance with limits indicated for unrestricted release of materials in some countries. The arising of the secondary waste is estimated. Decontamination of a 10 m**2 surface would typically produce 0.5 to 3.0 kg of dry waste, corresponding to 1.6 to 10 kg of concrete conditioned waste.
Bibliographic Reference: EUR 9303 EN (1984) FS, 87 P., BFR 300, EUROFFICE, LUXEMBOURG, POB 1003
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Record Number: 1989123010300 / Last updated on: 1987-01-01
Available languages: en